Low-water-head large-flow axial flow water turbine with double-inlet type volute
阅读说明：本技术 一种带有双进口式蜗壳的低水头大流量轴流式水轮机 (Low-water-head large-flow axial flow water turbine with double-inlet type volute ) 是由 阚阚 陈会向 陈雅楠 郑源 周大庆 戴景 许哲 于 2020-05-11 设计创作，主要内容包括：本发明公开了一种带有双进口式蜗壳的低水头大流量轴流式水轮机,所述双进口式蜗壳内侧环形开口处设置座环,所述座环内设置有一周活动导叶,所述座环底部设置有转轮,泄水锥底部穿过转轮,泄水锥顶部套接在座环内侧；所述转轮底部设置有尾水管；蜗状结构段圆周方向设置有两个进水管,进水管末端设置有向下的斜面段；所述尾水管末端设置有多个出水管。叶片的正面与反面从上至下由不同曲率的曲面平滑连接。本发明通过两个进水口双向进水,提高了蜗壳中圆周方向上水流的均匀性,增强了水流在圆周方向上的速度分量,进而有效增大来流的水流环量,改善进入导水机构的水流条件,减小导水机构的水力损失,具有水力性能好、运行效率高等优点。(The invention discloses a low-water-head large-flow axial flow water turbine with a double-inlet volute, wherein a seat ring is arranged at an annular opening at the inner side of the double-inlet volute, a circle of movable guide vanes are arranged in the seat ring, a rotating wheel is arranged at the bottom of the seat ring, the bottom of a water drainage cone penetrates through the rotating wheel, and the top of the water drainage cone is sleeved at the inner side of the seat ring; a tail water pipe is arranged at the bottom of the rotating wheel; two water inlet pipes are arranged in the circumferential direction of the volute-shaped structure section, and the tail ends of the water inlet pipes are provided with downward inclined surface sections; and a plurality of water outlet pipes are arranged at the tail ends of the draft tubes. The front surface and the back surface of the blade are smoothly connected by curved surfaces with different curvatures from top to bottom. The invention improves the uniformity of water flow in the circumferential direction in the volute casing and enhances the velocity component of the water flow in the circumferential direction by two-way water inlet of the two water inlets, thereby effectively increasing the water flow circulation of the incoming flow, improving the water flow condition entering the water distributor, reducing the hydraulic loss of the water distributor, and having the advantages of good hydraulic performance, high operation efficiency and the like.)
1. The utility model provides a large-traffic axial-flow hydraulic turbine of low head with two import formula volutes which characterized in that: the method comprises the following steps: the double-inlet volute comprises a double-inlet volute body, wherein a seat ring is arranged at an annular opening at the inner side of the double-inlet volute body, a circle of movable guide vanes are arranged in the seat ring, a rotating wheel is arranged at the bottom of the seat ring, the bottom of a water drainage cone penetrates through the rotating wheel, and the top of the water drainage cone is sleeved on the inner side of the seat ring; a tail water pipe is arranged at the bottom of the rotating wheel; the double-inlet volute comprises a volute-shaped structure section, two water inlet pipes are arranged in the circumferential direction of the volute-shaped structure section, and a downward inclined plane section is arranged at the tail end of each water inlet pipe; and a plurality of water outlet pipes are arranged at the tail ends of the draft tubes.
2. The low head high flow axial flow hydraulic turbine with dual inlet volute of claim 1, wherein: the two water inlet pipes are symmetrical about the center of the volute-shaped structure section.
3. The low head high flow axial flow hydraulic turbine with dual inlet volute of claim 1, wherein: the ratio b/a of the height to the width of the water inlet pipe is 1.5-2.5.
4. The low head high flow axial flow hydraulic turbine with dual inlet volute of claim 1, wherein: the runner comprises a rotating hub, a plurality of blades are uniformly arranged on the rotating hub, and the tail end of the water drainage cone penetrates through the rotating hub; the blade adopts the non-uniform thickness distortion structure, and the front and the reverse of blade are from last to down by the smooth connection of different camber's curved surface.
5. The low head high flow axial flow hydraulic turbine with dual inlet volute of claim 4, wherein: the front surface and the back surface of the blade are arranged as follows from top to bottom according to the section airfoil curve of the curved surface:
at a position which is 197mm away from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝0.00403x2+0.79114x+43.6953
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝0.00194x2+1.13114x+16.4691
at a position 217mm away from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝-1.77866×10-5x3+0.00842x2-0.26079x+58.4285
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝8.48×10-4x2+0.84773x-15.968
at a distance of 237mm from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝-1.7019×10-5x3+0.00872x2-0.78663x+71.7797
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝-6.5435×10-7x4+3.69186×10-4x3-0.0754x2+7.32065x-245.30075
at a distance of 257mm from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝-8.56475×10-6x3+0.00549x2-0.71048x+64.76445
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝-7.44012×10-20x3+0.00138x2+0.02538x-4.72338
at 277mm from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝9.2777×10-9x5-7.5269×10-6x4+0.00239x3-0.36764x2+27.42264x-773.0001
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝0.00131x2-0.19742x+1.04017
at the position 297mm away from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝3.33985×10-9x5-2.6039×10-6x4+7.91058x3-0.11593x2+8.00103x-205.0969
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝-3.885×10-10x5+4.4807×10-7x4-1.8185×10-4x3+0.0347x2-3.1998x+92.9279。
6. the low head high flow axial flow hydraulic turbine with the double inlet volute of claim 1,
the method is characterized in that: the centers of the double-inlet volute, the seat ring, the movable guide vane, the rotating wheel and the draft tube are in the same position
On the vertical axis.
7. The low head high flow axial flow hydraulic turbine with the double inlet volute of claim 4,
the method is characterized in that: the number of the blades is 5-10.
8. The low head high flow axial flow hydraulic turbine with the double inlet volute of claim 1,
the method is characterized in that: a plurality of flow guide piers are vertically arranged in the inclined plane section and are arranged at equal intervals.
Technical Field
The invention relates to a low-water-head large-flow axial flow water turbine with a double-inlet volute, belonging to the technical field of water turbines.
Background
In recent years, water turbines have become indispensable components in the hydroelectric power generation industry, the installed quantity of water turbines is large in China at present, and mixed-flow type, axial-flow type and through-flow type water turbines are widely applied. Axial flow turbines, also known as kaplan turbines, convert radial flow of water between a guide vane and a runner into axial flow, while maintaining axial flow in the runner region. The axial flow water turbine has lower applied water head than the mixed flow type, but has larger flow capacity than the mixed flow type when the diameter and the water head are the same, and is widely applied to medium and low water head and large flow hydropower stations. The axial flow hydraulic turbine runner is composed of a runner body and blades.
The volute is used as a water diversion component of the water turbine, and has the function of enabling water flow to form a ring amount from the hydraulic viewpoint so as to ensure that the water flow can enter the seat ring and the movable guide vane at a smaller attack angle and reduce the hydraulic loss of the water guide mechanism.
Disclosure of Invention
The purpose is as follows: in order to overcome the defects in the prior art, the invention provides a low-water-head large-flow axial flow water turbine with a double-inlet type volute.
The technical scheme is as follows: in order to solve the technical problems, the technical scheme adopted by the invention is as follows:
a low head high flow axial flow turbine with a dual entry volute comprising: the double-inlet volute comprises a double-inlet volute body, wherein a seat ring is arranged at an annular opening at the inner side of the double-inlet volute body, a circle of movable guide vanes are arranged in the seat ring, a rotating wheel is arranged at the bottom of the seat ring, the bottom of a water drainage cone penetrates through the rotating wheel, and the top of the water drainage cone is sleeved on the inner side of the seat ring; a tail water pipe is arranged at the bottom of the rotating wheel; the double-inlet volute comprises a volute-shaped structure section, two water inlet pipes are arranged in the circumferential direction of the volute-shaped structure section, and a downward inclined plane section is arranged at the tail end of each water inlet pipe; and a plurality of water outlet pipes are arranged at the tail ends of the draft tubes.
Preferably, the two water inlet pipes are symmetrical with respect to the center of the volute-shaped structure section.
Preferably, the ratio b/a of the height to the width of the water inlet pipe is 1.5 to 2.5.
Preferably, the runner comprises a rotating hub, a plurality of blades are uniformly arranged on the rotating hub, and the tail end of the water drainage cone penetrates through the rotating hub; the blade adopts the non-uniform thickness distortion structure, and the front and the reverse of blade are from last to down by the smooth connection of different camber's curved surface.
Preferably, the section airfoil curves of the curved surfaces of the front surface and the back surface of the blade from top to bottom are set as follows:
at a position which is 197mm away from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝0.00403x2+0.79114x+43.6953
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝0.00194x2+1.13114x+16.4691
at a position 217mm away from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝-1.77866×10-5x3+0.00842x2-0.26079x+58.4285
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝8.48×10-4x2+0.84773x-15.968
at a distance of 237mm from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝-1.7019×10-5x3+0.00872x2-0.78663x+71.7797
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝-6.5435×10-7x4+3.69186×10-4x3-0.0754x2+7.32065x-245.30075
at a distance of 257mm from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝-8.56475×10-6x3+0.00549x2-0.71048x+64.76445
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝-7.44012×10-20x3+0.00138x2+0.02538x-4.72338
at 277mm from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝9.2777×10-9x5-7.5269×10-6x4+0.00239x3-0.36764x2+27.42264x-773.0001
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝0.00131x2-0.19742x+1.04017
at the position 297mm away from the transverse axis of the lower edge of the drainage cone, the section airfoil curve formula of the curved surface of the front surface of the blade is as follows:
y＝3.33985×10-9x5-2.6039×10-6x4+7.91058x3-0.11593x2+8.00103x-205.0969
the section airfoil curve formula of the curved surface of the reverse surface of the blade is as follows:
y＝-3.885×10-10x5+4.4807×10-7x4-1.8185×10-4x3+0.0347x2-3.1998x+92.9279。
preferably, centers of the double-inlet volute, the seat ring, the movable guide vane, the rotating wheel and the draft tube are on the same vertical axis.
Preferably, the number of the blades is 5-10.
As a preferred scheme, a plurality of flow guide piers are vertically arranged in the inclined plane section and are arranged at equal intervals.
Has the advantages that: the low-water-head large-flow axial flow water turbine with the double-inlet volute provided by the invention has the advantages that the double-inlet volute is applied, water flows in two directions through the two water inlets in the volute, the uniformity of the water flow in the circumferential direction in the volute is improved, the velocity component of the water flow in the circumferential direction is enhanced, the circulation volume of the incoming water flow is further effectively increased, the water flow condition entering the water distributor is improved, the hydraulic loss of the water distributor is reduced, the hydraulic performance is good, the operation efficiency is high and the like.
Drawings
Fig. 1 is a schematic structural diagram of a low head high flow axial flow hydraulic turbine with a double-inlet type volute provided by the invention.
Fig. 2 is a top view structural diagram of a dual-inlet volute provided by the invention.
Fig. 3 is a schematic view of a seat ring and a runner according to the present invention.
Fig. 4 is a schematic sectional dimension view of a water inlet pipe according to the present invention.
Fig. 5 is a schematic view of a vane according to the present invention in a forward direction.
Fig. 6 is a radial schematic view of a blade according to the present invention.
FIG. 7 is a schematic view of airfoil profiles on blades of the present invention at different axial distances from the lower edge of the wash cone.
Detailed Description
The present invention will be further described with reference to the accompanying drawings.
Referring to fig. 1-3, a low-head large-flow axial flow water turbine with a double-inlet volute comprises a double-inlet volute 1, a seat ring 2, movable guide vanes 3, a rotating wheel 4 and a tail water pipe 5 in sequence according to a water inlet direction, wherein the seat ring 2 is arranged at an annular opening at the inner side of the double-inlet volute 1, a circle of movable guide vanes 3 are arranged in the seat ring 2, the rotating wheel 4 is arranged at the bottom of the seat ring 2, the rotating wheel 4 penetrates through the bottom of a water discharge cone 6, and the top of the water discharge cone 6 is sleeved on the inner side of the seat ring 2; a tail water pipe 5 is arranged at the bottom of the rotating wheel 4; the double-inlet volute 1 comprises a volute-shaped structure section 101, two water inlet pipes 102 are arranged in the circumferential direction of the volute-shaped structure section 101, and a downward inclined surface section 103 is arranged at the tail ends of the water inlet pipes 102; the tail end of the draft tube 5 is provided with a plurality of water outlet tubes 501.
As shown in fig. 4, the ratio b/a of the height to the width of the inlet pipe 102 is 1.5 to 2.5.
The two inlet pipes 102 are symmetrical about the volute centre.
The runner 4 comprises a rotating hub 401, a plurality of blades 402 are uniformly arranged on the rotating hub 401, and the tail end of the drain cone 6 penetrates through the rotating hub 401; as shown in fig. 5-6, the blade 402 is of a non-uniform thickness twisted structure, the front surface and the back surface of the blade 402 are smoothly connected from top to bottom by curved surfaces with different curvatures, and the section airfoil curves of the curved surfaces of the front surface and the back surface from top to bottom are set as follows:
as shown in FIG. 7, the coordinates of points on the airfoil curves of the front and back sections of the blade at a distance of 197mm from the transverse axis of the lower edge of the bleed cone are shown in Table 1.
TABLE 1
The two curves fitted are respectively represented as:
the front side of the blade is as follows: 0.00403x2+0.79114x+43.6953
Blade back: 0.00194x2+1.13114x+16.4691
The numerical values of the point coordinates on the airfoil curves of the front and back sections of the blade at a distance of 217mm from the transverse axis of the lower edge of the drainage cone are shown in Table 2.
TABLE 2
The two curves fitted are respectively represented as:
front face of blade is-1.77866 × 10-5x3+0.00842x2-0.26079x+58.4285
Blade back surface, y is 8.48 × 10-4x2+0.84773x-15.968
The values of the coordinates of the points on the airfoil curves of the front and back sections of the blade at a distance of 237mm from the transverse axis of the lower edge of the bleed cone are shown in table 3.
TABLE 3
The two curves fitted are respectively represented as:
front face of blade is-1.7019 × 10-5x3+0.00872x2-0.78663x+71.7797
Blade back y-6.5435 × 10-7x4+3.69186×10-4x3-0.0754x2+7.32065x-245.30075
The values of the coordinates of the points on the airfoil curves of the front and back sections of the blade at 257mm from the transverse axis of the lower edge of the bleed cone are shown in table 4.
TABLE 4
The two curves fitted are respectively represented as:
front face of blade is-8.56475 × 10-6x3+0.00549x2-0.71048x+64.76445
Blade back y-7.44012 × 10-20x3+0.00138x2+0.02538x-4.72338
The numerical values of the point coordinates on the airfoil curves of the front and back cross sections of the blade at 277mm from the transverse axis of the lower edge of the bleed cone are shown in table 5.
TABLE 5
The two curves fitted are respectively represented as:
the front side of the blade is as follows:
y＝9.2777×10-9x5-7.5269×10-6x4+0.00239x3-0.36764x2+27.42264x-773.0001 blade back: y is 0.00131x2-0.19742x+1.04017
The numerical values of the point coordinates on the airfoil curves of the front and back cross sections of the blade at a distance of 297mm from the transverse axis of the lower edge of the drainage cone are shown in Table 6.
TABLE 6
The two curves fitted are respectively represented as:
the front side of the blade is as follows:
y＝3.33985×10-9x5-2.6039×10-6x4+7.91058x3-0.11593x2+8.00103x-205.0969 blade back:
y＝-3.885×10-10x5+4.4807×10-7x4-1.8185×10-4x3+0.0347x2-3.1998x+92.9279
the centers of the double-inlet volute 1, the seat ring 2, the rotating wheel 4 and the draft tube 5 are on the same vertical axis.
The number of the blades 402 is 5-10.
A plurality of flow guide piers 104 are vertically arranged in the inclined plane section 103. The flow guiding piers 104 are arranged at equal intervals.