High-specific-speed axial flow water turbine with double-inlet volute

A technology with high specific speed and dual inlets, which is applied in the field of water turbines, can solve problems such as optimization of water inlet conditions, and achieve the effects of enhancing velocity components, increasing water flow circulation, and good hydraulic performance

CN111577508AInactive Publication Date: 2020-08-25HOHAI UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-08-25
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a high-specific-speed axial flow water turbine with a double-inlet volute. A seat ring is arranged in an annular opening in the inner side of the double-inlet volute, a circleof 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 drain cone penetrates through a rotating wheel, and the top of the drain cone is connected with the inner side of the seat ring in a sleeved mode; and a tail water pipe is arranged at the bottom of the rotating wheel, the rotating wheel comprises a rotating hub, a plurality of blades are uniformly arranged on the rotating hub, the tail end of the drain cone penetrates through the rotating hub, each blade is of a non-uniform-thickness twisted structure, and the front surface and the back surface of each blade are smoothly connected through curved surfaces with different curvatures from top to bottom. According to the high-specific-speed axial flow water turbine,double-direction water incoming is achieved through two water inlets, the uniformity of water flow in the volute in the circumferential direction is improved, and the velocity component of the waterflow in the circumferential direction is improved, so that the water flow circulation of the incoming flow is effectively improved, the water flow condition entering a water distributor is improved, the hydraulic loss of the water distributor is reduced, and the advantages of being high in hydraulic performance and high in operation efficiency and the like are achieved.
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Description

technical field

[0001] The invention relates to a high-specific-speed axial-flow water turbine with a double-inlet volute, which belongs to the technical field of water turbines. Background technique

[0002] In recent years, water turbines have become an indispensable part of the hydropower industry. At present, there are a large number of installed water turbines in my country, among which the mixed-flow, axial-flow and tubular water turbines are widely used. The axial flow turbine is also called the Kaplan type. The water flow changes from a radial flow to an axial flow between the guide vane and the runner, and the water flow maintains an axial flow in the runner area. The applied water head of the axial flow turbine is lower than that of the mixed flow type, but at the same diameter and head, its flow capacity is larger than that of the mixed flow type, and it is widely used in medium and low head and large flow hydropower stations. The runner of the axial flow turbine...

Examples

Embodiment 1

[0094] Take the application of the axial-flow turbine with double-inlet volute proposed by the present invention in a power station as an example. The water head of the power station is 28m, the design flood flow is 18500m3 / s, and the specific speed of the turbine is 600.

[0095] The optimization parameters of the present invention are: two water inlet pipes are arranged in the circumferential direction of the spiral structure section, the two water inlet pipes are symmetrical about the center of the spiral structure section, and the end of the water inlet pipe is provided with a downward slope section; the ratio of the height to the width of the water inlet pipe is b / a=2.2. The number of movable guide vanes is 32; the blades adopt non-equal thickness twisted structure, and the number is 5 pieces; the draft tube adopts an elbow-shaped draft tube, and the elevation angle of the top plate of the water outlet diffusion section is 11°.

Embodiment 2

[0097] The optimization parameters of the present invention are: two water inlet pipes are arranged in the circumferential direction of the spiral structure section, the two water inlet pipes are symmetrical about the center of the spiral structure section, and the end of the water inlet pipe is provided with a downward slope section; the ratio of the height to the width of the water inlet pipe is b / a=1.9. The number of movable guide vanes is 32; the blades adopt non-equal thickness twisted structure, and the number is 5 pieces; the draft tube adopts an elbow-shaped draft tube, and the elevation angle of the top plate of the water outlet diffusion section is 11°.

Embodiment 3

[0099] The specific application process of the present invention is: the pressurized water flow in the two inlet pipes connected by the double-inlet volute of the present invention generates a center-symmetrical tangential flow in the circumferential direction of the volute structure section through the flow guide pier, so that the water flow A sufficiently large circulation is generated before entering the water guiding mechanism, and the water flowing out of the water guiding mechanism pushes the runner to rotate, thereby converting the energy of the water flow into rotational mechanical energy. The water flow comes out from the runner and is discharged downstream through the draft tube.