Turbine runner and hydraulic turbine

Abstract

The application discloses a runner for a hydraulic turbine and the hydraulic turbine. The runner comprises an upper crown, a lower ring and a plurality of blades. The plurality of blades are connected between the upper crown and the lower ring, and are distributed at intervals around an axis of the runner. Each blade comprises a high-pressure side and a low-pressure side. The low-pressure side is located on a side of the high-pressure side close to the axis. The high-pressure side is arranged to be inclined relative to the axis direction of the runner. An included angle between the high-pressure side and the axis direction of the runner is 15-60 degrees. The runner disclosed by the application greatly reduces pressure pulsation of a flow passage of the runner, especially pressure pulsation of a high-pressure side of the runner. The amplitude of alternating stress caused by the high-pressure side pressure pulsation is reduced. High-cycle fatigue damage of the runner is avoided. The stability and safety of the runner operation are improved. The runner is not only suitable for high-head hydroelectric generating units, but also suitable for high-lift water pump units.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydraulic turbines, and particularly relates to a runner for a hydraulic turbine and the hydraulic turbine. BACKGROUND

[0002] Hydropower energy is one of the most widely used renewable clean energies in the world, and its economic, social and environmental benefits are significant. In the context of global climate change and energy crisis, the booming hydropower energy is increasingly important in the new energy system. Compared with medium and low head hydropower units, high head units have high speed, complex and variable internal flow, and high pressure pulsation amplitude, which makes the design and safe operation of high head hydropower units face more challenges. SUMMARY

[0003] The embodiments of the application provide a runner for a hydraulic turbine and the hydraulic turbine to reduce the pressure pulsation of the runner and improve the operation stability and safety of the runner.

[0004] According to a first aspect of the application, the application provides a runner for a hydraulic turbine, which comprises: an upper crown; a lower ring; and a plurality of blades connected between the upper crown and the lower ring, the plurality of blades are distributed at intervals around an axis of the runner, each blade comprises a high-pressure side and a low-pressure side, the low-pressure side is located on a side of the high-pressure side close to the axis, the high-pressure side is arranged obliquely relative to a direction of the axis of the runner, and an included angle between the high-pressure side and the direction of the axis of the runner is 15°-60°.

[0005] In some embodiments, the plurality of blades comprises a plurality of first blades and a plurality of second blades, the plurality of first blades and the plurality of second blades are alternately and at intervals distributed around the axis of the runner; the first blade comprises a first high-pressure side and a first low-pressure side, and the second blade comprises a second high-pressure side and a second low-pressure side, and a length of the first blade extending from the first high-pressure side to the first low-pressure side is greater than a length of the second blade extending from the second high-pressure side to the second low-pressure side.

[0006] In some embodiments, a first included angle between the first high-pressure side and the direction of the axis of the runner and a second included angle between the second high-pressure side and the direction of the axis of the runner are the same.

[0007] In some embodiments, a first distance between the first high-pressure side and an axis center of the runner is equal to a second distance between the second high-pressure side and the axis center of the runner.

[0008] In some embodiments, the first blade further comprises a first surface and a second surface connected between the first high-pressure side and the first low-pressure side, the first surface and the second surface are oppositely arranged along a thickness direction of the first blade; the second blade further comprises a third surface and a fourth surface connected between the second high-pressure side and the second low-pressure side, the third surface and the fourth surface are oppositely arranged along a thickness direction of the second blade; and the first surface, the second surface, the third surface and the fourth surface are all three-dimensional twisted surfaces.

[0009] In some embodiments, the twist shape of the first surface and the second surface is the same, and the twist shape of the third surface and the fourth surface; the twist shape of the first surface and the second surface is different from the twist shape of the third surface and the fourth surface.

[0010] In some embodiments, the length of the second blade is 1 / 2-4 / 5 of the length of the first blade.

[0011] In some embodiments, the number of the first blade and the second blade is 5-15.

[0012] In some embodiments, the curvature fitting formula of the blade bone line of the first blade is y1=0.06x1 2 -0.26x1+0.92, wherein y1 represents the longitudinal coordinate value of the blade bone line of the first blade in a first preset coordinate system, x1 represents the horizontal coordinate value of the blade bone line of the first blade in the first preset coordinate system, the horizontal coordinate direction of the first preset coordinate system is the axial surface streamline direction of the first blade, and the longitudinal coordinate direction of the first preset coordinate system is the thickness direction of the first blade.

[0013] In some embodiments, the curvature fitting formula of the blade bone line of the second blade is y2=0.002x2 3 +0.063x2 2 +0.796x2-0.19, wherein y2 represents the longitudinal coordinate value of the blade bone line of the second blade in a second preset coordinate system, x2 represents the horizontal coordinate value of the blade bone line of the second blade in the second preset coordinate system, the horizontal coordinate direction of the second preset coordinate system is the axial surface streamline direction of the second blade, and the longitudinal coordinate direction of the second preset coordinate system is the thickness direction of the second blade.

[0014] In some embodiments, the blade comprises two curved surfaces oppositely arranged along the thickness direction of the blade, and each curved surface is smoothly connected with the high-pressure side and the low-pressure side.

[0015] According to a second aspect of the present application, the present application further provides a water turbine comprising the runner provided according to any embodiment of the present application.

[0016] The runner for hydraulic turbine provided by the embodiment of the application comprises an upper crown, a lower ring and a plurality of blades, the plurality of blades are connected between the upper crown and the lower ring and are distributed at intervals around the axis of the runner to form flow channels between adjacent blades. Each blade comprises a high-pressure side and a low-pressure side, and the low-pressure side is located on the side of the high-pressure side close to the axis. The high-pressure side is arranged to be inclined relative to the direction of the axis of the runner, and the included angle between the high-pressure side and the direction of the axis of the runner is 15°-60°. That is, the high-pressure side is greatly inclined relative to the direction of the axis of the runner, effectively buffers the water flow pressure in the flow channel of the runner, can greatly reduce the pressure pulsation of the flow channel of the runner, especially the pressure pulsation of the high-pressure side of the runner, reduces the amplitude of the alternating stress caused by the pressure pulsation of the high-pressure side, avoids high-cycle fatigue damage of the runner, improves the stability and safety of the operation of the runner, and makes the runner not only suitable for low-head hydroelectric generating set, but also suitable for high-head hydroelectric generating set and high-lift water pump set with a head of 200-800 meters. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments of the application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0018] Figure 1 FIG. 1 is a structural schematic diagram of a runner for hydraulic turbine provided by an embodiment of the application.

[0019] Figure 2 FIG. 2 is a structural schematic diagram of the runner shown in FIG. 1 after removing the upper crown. Figure 1

[0020] Figure 3 FIG. 3 is a structural schematic diagram of a first blade of the runner shown in FIG. 1. Figure 1

[0021] Figure 4 FIG. 4 is a structural schematic diagram of a second blade of the runner shown in FIG. 1. Figure 1 DETAILED DESCRIPTION

[0022] The embodiments of the technical solutions of the application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the application, and therefore only serve as examples, and cannot limit the protection scope of the application.

[0023] ​​​Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise noted, the terms "including" and "comprising" are open-ended and do not exclude the presence of unrecited elements or limitations.

[0024] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0025] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, or necessarily alternatives to other embodiments. It will be explicitly and implicitly appreciated by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, m and / or n, which can represent the three cases of m alone, m and n together, and n alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after it.

[0027] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two).

[0028] In the description of the embodiments of the present application, the technical terms "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0029] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "linking", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0030] In the embodiments of the present application, "parallel" not only includes the case of absolute parallel, but also includes the case of approximate parallel which is generally recognized in engineering; at the same time, "perpendicular" not only includes the case of absolute perpendicular, but also includes the case of approximate perpendicular which is generally recognized in engineering. Illustratively, the included angle between two directions is 85°-90°, which can be considered as perpendicular; the included angle between two directions is 0°-5°, which can be considered as parallel.

[0031] With the continuous enhancement of people's environmental protection and energy saving concept, the demand of society for using clean and renewable energy to achieve energy saving and emission reduction and reduce environmental pollution is also increasing, so that the water power generation industry is favored. Among them, the water turbine is a power machine capable of converting the energy of water flow into rotary mechanical energy. When the water flow is introduced to the runner of the water turbine, the water flow can drive the runner to rotate to drive the generator to generate electricity.

[0032] For high head water turbine unit, its rotating speed is high, internal flow is complex and changeable, pressure pulsation amplitude is high, etc., which often causes serious accidents of runner fatigue failure, seriously threatening the efficient and stable operation of the unit and the life safety of the power station staff.

[0033] Therefore, the embodiment of the present application provides a runner for water turbine, which can greatly reduce the pressure pulsation of the runner through simple structure design, thereby improving the operation stability and safety thereof.

[0034] The embodiments will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0035] The embodiment of the present application provides a runner for water turbine, Figure 1 is a structural schematic diagram of the runner for water turbine provided by an embodiment of the present application, Figure 2 is Figure 1 is a structural schematic diagram of the runner shown in Figure 1 and Figure 2The runner 1 for a hydraulic turbine provided by the embodiments of the present application comprises an upper crown 10, a lower ring 20, and a plurality of blades 30. The plurality of blades 30 are connected between the upper crown 10 and the lower ring 20, and are spaced around the axis a of the runner 1. Each blade comprises a high-pressure side and a low-pressure side, and the low-pressure side is located on the side of the high-pressure side close to the axis a. The high-pressure side is inclined relative to the axis direction of the runner 1, and the included angle between the high-pressure side and the axis direction of the runner 1 is 15°-60°.

[0036] The plurality of blades 30 are spaced in the circumferential direction of the runner, so that flow channels can be formed between adjacent blades for water flow.

[0037] The plurality of blades 30 are independently connected between the upper crown 10 and the lower ring 20, and there is no connection relationship between the blades. The connection mode between the blades and the upper crown 10 and the connection mode between the blades and the lower ring 20 can be various, and the connection mode between the blades and the upper crown 10 can be the same as or different from the connection mode between the blades and the lower ring 20. Alternatively, the blades can be welded to the upper crown 10 and the lower ring 20.

[0038] The high-pressure side of the blade is adjacent to the radial outer side of the runner 1, and the low-pressure side of the blade is adjacent to the radial inner side of the runner 1. The lower ring 20 is used to fix the blades of the runner 1 to prevent the blades from falling off or shifting during operation. Water flow can flow into the runner 1 through the high-pressure side of the runner 1, and then flow out of the runner 1 from the low-pressure side after flowing through the flow channels of the runner 1.

[0039] The high-pressure side of the runner 1 is the radial outer side of the upper crown 10 and the lower ring 20, that is, the side where the high-pressure side of the blade 30 is located. The low-pressure side of the runner 1 is the bottom end of the lower ring 20 away from the upper crown 10.

[0040] The high-pressure side is connected to the radial outer edge of the lower ring 20 on the side adjacent to the lower ring 20 in the axis direction of the runner 1, and is connected to the radial outer edge of the upper crown 10 on the side adjacent to the upper crown 10 in the axis direction of the runner 1. The outer diameter of the upper crown 10 and the outer diameter of the lower ring 20 are substantially the same.

[0041] The high-pressure side can be inclined relative to the axis direction of the runner 1 in a first direction, or can be inclined relative to the axis direction of the runner 1 in a second direction opposite to the first direction. The inclination directions of the high-pressure sides of the blades relative to the axis direction of the runner 1 are consistent.

[0042] Alternatively, the included angle between the high-pressure side and the axis direction of the runner 1 can be 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, or 60°.

[0043] Preferably, the included angle between the high-pressure side and the axis direction of the runner 1 can be 30°-60°, which is more effective.

[0044] If the angle between the high-pressure side and the axis direction of the runner 1 is too small, that is, the inclination of the high-pressure side is too small, the pressure pulsation on the high-pressure side of the runner 1 and the alternating stress on the high-pressure side of the runner 1 cannot be reduced. If the angle between the high-pressure side and the axis direction of the runner 1 is too large, that is, the inclination of the high-pressure side is too large, the stress of the blade will be increased, which may cause deformation or fatigue damage of the blade. Therefore, in the embodiments of the present application, the angle between the high-pressure side and the axis direction of the runner 1 is set to 15°-60°, that is, the high-pressure side is greatly inclined relative to the axis direction of the runner 1, effectively buffers the water flow pressure in the runner channel, and makes the pressure distribution on the surface of the blade more uniform, reduces water flow diversion and turbulence, and can greatly reduce the pressure pulsation of the runner channel, especially the pressure pulsation on the high-pressure side of the runner (the peak value of the pressure pulsation can be reduced to less than 10% of the water head). At the same time, the amplitude of the alternating stress caused by the pressure pulsation on the high-pressure side can be reduced, avoiding high-cycle fatigue damage of the runner, improving the stability and safety of the operation of the runner, and making the runner not only suitable for low-head hydroelectric generating units, but also suitable for high-head hydroelectric generating units with a head of 200-800 meters and high-lift pump units.

[0045] The runner 1 provided by the embodiments of the present application can be adapted to different high-head hydroelectric stations, pumped storage power stations, and can also be used in pump stations with different lift, and has wide application value.

[0046] In some embodiments, the plurality of blades 30 includes a plurality of first blades 31 and a plurality of second blades 32, and the plurality of first blades 31 and the plurality of second blades 32 are alternately and spacedly distributed around the axis a of the runner 1. The first blade 31 includes a first high-pressure side 311 and a first low-pressure side 312, and the second blade 32 includes a second high-pressure side 321 and a second low-pressure side 322. The length of the first blade 31 extending from the first high-pressure side 311 to the first low-pressure side 312 is greater than the length of the second blade 32 extending from the second high-pressure side 321 to the second low-pressure side 322.

[0047] The first high-pressure side 311 is a side of the first blade 31 away from the axis a of the runner in the radial direction, and the first low-pressure side 312 is a side of the first blade 31 close to the axis a of the runner in the radial direction. Similarly, the second high-pressure side 321 is a side of the second blade 32 away from the axis a of the runner in the radial direction, and the second low-pressure side 322 is a side of the second blade 32 close to the axis a of the runner in the radial direction.

[0048] Optionally, the first high-pressure side 311 and the second high-pressure side 321 can be adjacent to the radially outer side edge of the lower ring 20, and the first low-pressure side 312 and the second low-pressure side 322 can be adjacent to the radially inner side of the lower ring 20. The distance between the first low-pressure side 312 and the radially inner side edge of the lower ring 20 is greater than the distance between the second low-pressure side 322 and the radially inner side edge of the lower ring 20.

[0049] The first blades 31 are identical in shape, and the second blades 32 are identical in shape.

[0050] The first blades 31 and the second blades 32 are distributed in a rotationally symmetrical structure around the axis a of the runner 1.

[0051] The runner of the embodiments of the present application adopts the first blades 31 and the second blades 32 of different lengths which are alternately distributed, so that the fluid control flexibility in the flow passage of the runner can be improved, the flow state of the water flow in the flow passage of the runner is improved, the water flow in the flow passage flows more uniformly, and thus the hydraulic efficiency of the runner is improved.

[0052] In addition, the first blades 31 and the second blades 32 of different lengths in combination can also enhance the adaptability of the runner 1 under different working conditions, so that the runner 1 can safely and stably operate under different water heads, flow rates and load conditions.

[0053] Meanwhile, the first blades 31 and the second blades 32 of different lengths in combination can also improve the overall structural width of the runner 1, especially the stiffness of the high-pressure side of the runner 1, so as to improve the reliability, durability and economy of the runner 1, and reduce the maintenance cost of the runner 1.

[0054] In some embodiments, the first included angle a between the first high-pressure side 311 and the axis direction of the runner 1 and the second included angle β between the second high-pressure side 321 and the axis direction of the runner 1 are the same.

[0055] It can be understood that the first included angle a and the second included angle β are both 15°-60°, and preferably 30°-60°.

[0056] The first included angle a between each first high-pressure side 311 and the axis direction of the runner 1 is the same, and the second included angle β between each second high-pressure side 321 and the axis direction of the runner 1 is the same.

[0057] The embodiments of the present application set the first included angle a and the second included angle β to be the same, so that the pressure distribution of the water flow on the surface of the first blade 31 and the second blade 32 close to the high-pressure side of the runner is more uniform, thereby reducing local stress concentration, improving the structural stability of each blade, prolonging the service life of the blade, and at the same time, the design process and manufacturing process can also be simplified, and the complexity and cost of manufacturing are reduced.

[0058] In some embodiments, the first distance between the first high-pressure side 311 and the axis of the runner 1 is equal to the second distance between the second high-pressure side 321 and the axis of the runner 1.

[0059] Alternatively, the first high-pressure side 311 and the second high-pressure side 321 are both at the edge radially outside the upper crown 10 and the lower ring 20.

[0060] The first high-pressure edge 311 of each first blade 31 is spaced at a first distance from the axis of the rotor 1, and the second high-pressure edge 321 of each second blade 321 is spaced at a second distance from the axis of the rotor 1. The distances between the high-pressure edge of each blade and the axis of the rotor 1 are all equal.

[0061] In this embodiment, the distance between the high-pressure side of the long and short blades and the axis of the impeller 1 is set to be equal, so that the water can flow into each channel evenly. This makes the pressure distribution of the water flow on the surface of each blade near the high-pressure side of the impeller more uniform, thereby reducing local stress concentration, improving the structural stability of each blade, extending the blade life, and simplifying the design process and manufacturing process, reducing the complexity and cost of manufacturing.

[0062] Figure 3 yes Figure 1 The diagram shows the structure of the first blade of the rotor. Figure 4 yes Figure 1 A schematic diagram of the structure of the second blade of the rotor is shown. In some embodiments, refer to... Figures 2 to 4 The first blade 31 further includes a first surface 313 and a second surface 314 connected between the first high-pressure side 311 and the first low-pressure side 312. The first surface 313 and the second surface 314 are disposed opposite to each other along the thickness direction of the first blade 31. The second blade 32 further includes a third surface 323 and a fourth surface 324 connected between the second high-pressure side 321 and the second low-pressure side 322. The third surface 323 and the fourth surface 324 are disposed opposite to each other along the thickness direction of the second blade 32. The first surface 313, the second surface 314, the third surface 323, and the fourth surface 324 are all three-dimensional twisted surfaces.

[0063] Both the first blade 31 and the second blade 32 can be sheet-like components.

[0064] Specifically, the first blade 31 has a first high-pressure side 311 and a first low-pressure side 312 at its two opposite ends along its length direction, and the first blade 31 is connected to the upper crown 10 and the lower ring 20 on both sides along the direction parallel to the axis of the wheel. The first blade 31 has a first surface 313 and a second surface 314 on both sides along its thickness direction.

[0065] The second blade 32 has a second high-pressure side 321 and a second low-pressure side 322 at its two opposite ends along its length direction. The two sides of the second blade 32 along the direction parallel to the axis of the rotor are connected to the upper crown 10 and the lower ring 20, respectively. The two sides of the second blade 32 along its thickness direction are the third surface 323 and the fourth surface 324, respectively.

[0066] Optionally, the thickness of the first blade 31 and the second blade 32 can be uniform, in which case the first surface 313 and the second surface 314 have the same curved surface shape, and the third surface 323 and the fourth surface 324 have the same curved surface shape.

[0067] Optionally, the thickness of the first blade 31 and the second blade 32 can also be non-uniform, in which case the first surface 313 and the second surface 314 have different curved surface shapes, and the third surface 323 and the fourth surface 324 have different curved surface shapes.

[0068] In the embodiments of the present application, the surfaces of the first blade 31 and the second blade 32 are all set as three-dimensional twisted curved surfaces, which can optimize the flow state in the runner channel. Compared with the circular-arc-shaped blades, the first blade 31 and the second blade 32 in the three-dimensional twisted shape in the embodiments of the present application have higher hydraulic efficiency.

[0069] In some embodiments, the twisted shapes of the first surface 313 and the second surface 314 are the same, and the twisted shapes of the third surface 323 and the fourth surface 324 are the same. The twisted shapes of the first surface 313 and the second surface 314 are different from the twisted shapes of the third surface 323 and the fourth surface 324.

[0070] The thickness of the first blade 31 is uniform, and the first surface 313 and the second surface 324 oppositely arranged along the thickness direction of the first blade 31 have the same twisted shape.

[0071] The thickness of the second blade 32 is uniform, and the third surface 323 and the fourth surface 324 oppositely arranged along the thickness direction of the second blade 32 have the same twisted shape.

[0072] In the embodiments of the present application, the first blade 31 and the second blade 32 are set to different twisted shapes, which can better control the flow state of the water flow in the runner channel, reduce pressure pulsation and blade channel vortex, and improve the hydraulic efficiency of the runner 1.

[0073] In some embodiments, the length of the second blade 32 is 1 / 2-4 / 5 of the length of the first blade 31.

[0074] It should be noted that the length of the second blade 32 refers to the length of the second blade 32 extending from the second high-pressure side 321 to the second low-pressure side 322. The length of the first blade 31 refers to the length of the first blade 31 extending from the first high-pressure side 311 to the first low-pressure side 312.

[0075] The length of the second blade 32 is set to 1 / 2-4 / 5 of the length of the first blade 31 in the embodiment of the application, which can ensure the best flow state of the runner channel and improve the energy conversion efficiency. If the length of the second blade 32 is too short, the water flow cannot be effectively controlled, which leads to water flow separation and increased turbulence, affecting the hydraulic performance of the runner 1. If the length of the second blade 32 is too long, the water flow resistance will be increased, resulting in energy loss and reducing the overall efficiency of the runner 1.

[0076] In some embodiments, the number of the first blades 31 and the second blades 32 is 5-15.

[0077] Alternatively, the number of the first blades 31 and the second blades 32 can be the same or different. For example, the number of the first blades 31 and the second blades 32 can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15.

[0078] In the embodiment of the application, the number of the first blades 31 and the second blades 32 is set to 5-15, which can form a proper number of flow channels in the runner 1, which is beneficial to improve the hydraulic efficiency of the runner.

[0079] In some embodiments, the curvature fitting formula of the blade skeleton line 315 of the first blade 31 is y1=0.06x1 2 -0.26x1+0.92, wherein y1 represents the longitudinal coordinate value of the blade skeleton line 315 of the first blade 31 in the first preset coordinate system, x1 represents the transverse coordinate value of the blade skeleton line 315 of the first blade 31 in the first preset coordinate system, the transverse coordinate direction of the first preset coordinate system is the axial surface streamline direction of the first blade 31, and the longitudinal coordinate direction of the first preset coordinate system is the thickness direction of the first blade 31.

[0080] The blade skeleton line 315 of the first blade 31 can generally represent the twisted shape of the first blade 31 from the high-pressure side to the low-pressure side.

[0081] In the embodiment of the application, the curvature fitting formula of the blade skeleton line 315 of the first blade 31 is set to y1=0.06x1 2 -0.26x1+0.92, which can make the flow state of the runner 1 more stable and further reduce the pressure pulsation.

[0082] In some embodiments, the curvature fitting formula of the blade skeleton line 325 of the second blade 32 is y2=0.002x2 3 +0.063x2 2+0.796x2-0.19, wherein y2 represents a longitudinal coordinate value of the blade bone line 325 of the second blade 32 in a second preset coordinate system, x2 represents a transverse coordinate value of the blade bone line 325 of the second blade 32 in the second preset coordinate system, the transverse coordinate direction of the second preset coordinate system is the meridian direction of the second blade 32, and the longitudinal coordinate direction of the second preset coordinate system is the thickness direction of the second blade 32.

[0083] The blade bone line 325 of the second blade 32 can substantially represent the twisted shape of the second blade 32 from the high-pressure side to the low-pressure side.

[0084] In the embodiment of the present application, the curvature fitting formula of the blade bone line 325 of the second blade 32 is set to y2=0.002x2 3 +0.063x2 2 +0.796x2-0.19, so that the flow state of the flow passage of the runner 1 is more stable, and the pressure pulsation is further reduced.

[0085] In some embodiments, the blade includes two curved surfaces oppositely arranged along the thickness direction of the blade, and each curved surface is smoothly connected with the high-pressure side and the low-pressure side.

[0086] Optionally, the plurality of blades 30 can include a plurality of first blades 31 and a plurality of second blades 32. Taking the first blade 31 as an example, the two curved surfaces of the first blade 31 are a first surface 313 and a second surface 314, the first surface 313 is smoothly connected with the first high-pressure side 311, and the first surface 313 is smoothly connected with the first low-pressure side 312. The second surface 314 is smoothly connected with the first high-pressure side 311, and the second surface 314 is smoothly connected with the first low-pressure side 312. In this way, the external edge of the first blade 31 for contacting the water flow is smooth, the resistance generated by the first blade 31 to the water flow is reduced, and the vortex loss of the water flow is reduced.

[0087] Similarly, the external edge of the second blade 32 is also relatively smooth, the resistance generated by the second blade 32 to the water flow is reduced, and the vortex loss of the water flow is reduced.

[0088] In the embodiment of the present application, the surface of the blade is set to a curved surface, and the curved surface is smoothly connected with the high-pressure side and the low-pressure side, so that the water flow resistance can be reduced to the greatest extent, the vortex loss is reduced, and the hydraulic efficiency of the runner 1 is improved.

[0089] According to the second aspect of the present application, the embodiment of the present application further provides a water turbine, which includes the runner 1 provided by any one of the above-mentioned embodiments.

[0090] Since the water turbine provided by the embodiment of the present application includes the runner 1 provided by any one of the above-mentioned embodiments, the water turbine has the corresponding technical effects of the runner 1, which will not be described in detail here.

[0091] The above description is provided as an enabling teaching of the application and is not intended to limit its scope in any way. Any modification of the application in keeping with the spirit thereof that is apparent to those skilled in the art is to be considered within the scope of the application as defined by the appended claims.

Claims

1. A runner for a hydraulic turbine, characterized by The turbine comprises: an upper crown; a lower ring; and a plurality of blades connected between the upper crown and the lower ring, the plurality of blades being spaced apart around an axis of the turbine, each of the blades comprising a high-pressure side and a low-pressure side, the low-pressure side being located on a side of the high-pressure side close to the axis, the high-pressure side being inclined with respect to a direction of the axis of the turbine, an angle between the high-pressure side and the direction of the axis of the turbine being 30°-60°; the plurality of blades comprising a plurality of first blades and a plurality of second blades, the plurality of first blades and the plurality of second blades being alternately spaced apart around the axis of the turbine; the first blades comprising a first high-pressure side and a first low-pressure side, the second blades comprising a second high-pressure side and a second low-pressure side, a length of the first blade extending from the first high-pressure side to the first low-pressure side being greater than a length of the second blade extending from the second high-pressure side to the second low-pressure side; the length of the second blade being 1 / 2-4 / 5 of the length of the first blade. A curvature fitting formula of a blade bone line of the first blade is y1=0.06x1 2 -0.26x1+0.92, wherein y1 represents a longitudinal coordinate value of the blade bone line of the first blade in a first preset coordinate system, x1 represents a transverse coordinate value of the blade bone line of the first blade in the first preset coordinate system, the transverse coordinate direction of the first preset coordinate system is the axial surface streamline direction of the first blade, and the longitudinal coordinate direction of the first preset coordinate system is the thickness direction of the first blade. The curvature fitting formula of the blade bone line of the second blade is y2=0.002x2 3 +0.063x2 2 +0.796x2-0.19, wherein y2 represents the longitudinal coordinate value of the blade bone line of the second blade in a second preset coordinate system, x2 represents the transverse coordinate value of the blade bone line of the second blade in the second preset coordinate system, the transverse coordinate direction of the second preset coordinate system is the axial surface streamline direction of the second blade, and the longitudinal coordinate direction of the second preset coordinate system is the thickness direction of the second blade.

2. The turbine according to claim 1, wherein: a first angle between the first high-pressure side and the direction of the axis of the turbine is the same as a second angle between the second high-pressure side and the direction of the axis of the turbine.

3. The turbine according to claim 1, wherein: a first distance between the first high-pressure side and an axis of the turbine is the same as a second distance between the second high-pressure side and the axis of the turbine.

4. The turbine according to claim 1, wherein: the first blade further comprises a first surface and a second surface connected between the first high-pressure side and the first low-pressure side, the first surface and the second surface being oppositely arranged along a thickness direction of the first blade; the second blade further comprises a third surface and a fourth surface connected between the second high-pressure side and the second low-pressure side, the third surface and the fourth surface being oppositely arranged along a thickness direction of the second blade; the first surface, the second surface, the third surface and the fourth surface are three-dimensional twisted surfaces.

5. The turbine according to claim 4, wherein: the first surface and the second surface have the same twisted shape, and the third surface and the fourth surface have the same twisted shape; the first surface and the second surface have different twisted shapes from the third surface and the fourth surface.

6. The turbine according to claim 1, wherein: a number of the first blades and the second blades is 5-15.

7. The turbine according to claim 1, wherein: the blade comprises two curved surfaces oppositely arranged along a thickness direction of the blade, each of the curved surfaces being smoothly connected to the high-pressure side and the low-pressure side. The turbine according to any one of claims 1-7.

8. A hydraulic turbine characterized by ​

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