CN103206331A - Low-head efficient shaft-extension tubular pump turbine and blades thereof - Google Patents

Abstract

The invention relates to a low water head shaft extension tubular water pump turbine and blades thereof, belonging to the technical field of energy and power. It includes a water pump turbine, a reversible motor, a flow channel and a flow guide mechanism, and the flow channel includes a water inlet section flow channel, a guide vane section flow channel, a runner chamber and an S-shaped draft tube flow channel; the runner It is connected with the reversible motor through the main shaft transmission, and the other side of the runner is provided with a guide mechanism; the runner includes a hub of the runner and a water discharge cone, and the hub of the runner is uniformly arranged with blades along the circumference, and the blades The shape is thick in the middle and thin on both sides, and it is a three-dimensional distorted curved surface in space. Its spatial characteristics are represented by three sections: the upper, middle, and lower sections; A runner needs to meet the dual needs of pumping water and generating electricity at the same time, and the efficiency of taking into account the two operating conditions at the same time is suitable for low-head pumped storage power plants.

Description

A low-head high-efficiency shaft extension tubular pump turbine and its blades

technical field

The invention relates to a low-head, high-efficiency shaft-extension tubular pump-turbine used in a pumped-storage power station with a low head. The pump-turbine belongs to the field of fluid machinery and engineering equipment.

Background technique

Since the reform and opening up, with the rapid development of my country's economic construction and the continuous improvement of people's living standards, the power supply has become increasingly tense, and the peak-to-valley difference has gradually increased. Based on the requirements of ensuring the safety and effective operation of the power grid, the pumped storage power station, as a power station with special characteristics: peak-shaving and valley-filling, frequency regulation, voltage regulation, emergency backup, black start and other functions, will be the strategic focus of my country's power grid development. The working method of the pumped storage power station is to use the excess electric energy in the power system to pump the water in the low-elevation reservoir (commonly known as the "lower pool") to the high-altitude reservoir (commonly known as the "upper pool") and store it in the form of potential energy. When the system needs power, it will discharge water from the upper pool to the lower pool for power generation. Generally speaking, pumped storage power stations are high-head power stations, and their stand-alone capacity is also large, and they mainly operate in conjunction with the power grid. At present, there have been relatively in-depth researches on medium and high head and large capacity pump turbines at home and abroad, accumulated experience in design, construction and operation management, and achieved fruitful technical results. However, with the development of new energy sources such as wind energy, solar energy, ocean tidal current energy and other new energy sources, due to the instability of these energy sources, such as solar energy can only generate electricity when there is sun, and wind power can only generate electricity when the wind reaches a certain intensity. Only then can wind power be generated. In particular, these energy sources may be far away from the large power grid during the development and application process, such as some remote areas such as islands. The use of these new energy sources forms an isolated small power system. In the small power system of mixed multi-energy applications, the pumped storage power station can be used to regulate, store energy when other energy sources are in excess, and provide energy when other energy sources are insufficient. Such pumped storage power plants generally have a very low water head, generally below 50 m, and some only have about 10 m. This patent provides a pump turbine runner with low head pumped storage. The pump-turbine runner is a cross-flow two-way three-blade runner. In order to reduce investment and facilitate layout, the power station adopts a shaft extension through-flow arrangement.

Shaft-extension tubular pump turbines are rarely studied in my country. The main reasons are the flow channel design of the shaft-extension tubular unit, the overall structural type of the unit, the design optimization of high-performance runners and the connection mode of the speed increaser. The lack of in-depth research and design of key technologies, such as shaft extension tubular units with simple structure, convenient installation and maintenance, excellent hydraulic performance, and less civil engineering, has not been developed and popularized. At the same time, my country's low-head hydraulic resources are very rich, especially in East China, South China and coastal areas, where industrial and agricultural production is developed, and the demand for electricity is increasing rapidly. Research on new shaft extension tubular units and apply them to low-head pumped storage It has far-reaching significance for the development of comprehensive utilization of new energy.

Contents of the invention

The present invention proposes a low-head shaft-extension tubular pump-turbine to solve the problem that the two water flow directions of the pump-turbine power generation and pumping conditions are opposite. Efficiency for two operating conditions.

The technical solution proposed by the present invention to solve the above-mentioned technical problems is: a blade of a low water head axially extending through-flow water pump turbine, the shape of the blade is thick in the middle and thin on both sides, and it is a three-dimensional distorted curved surface in space. Three sections are represented; at the same time, the middle section adopts a new type of line, which is composed of curves connected end to end at the upper and lower ends. The coordinate system is established with the center point of each type line of the three sections as the origin, x _1, x _{2 and} x ₃ are the abscissas of each coordinate, y ₁ , y ₂ , and y ₃ are the ordinates of each coordinate, and F1, F2, and F3 respectively represent the three molded lines, then the position of the part point of the blade in the Cartesian coordinate system As shown in the table below:

serial number 101 102 103 104 105 106 107 108 109 the F1 on_X1 -59.552 -50.0 -40.0 -20.0 0.0 20.0 30.896 40.0 52.836 the F1 on_Y1 16.119 15.821 14.627 9.851 1.642 -6.119 -9.851 -12.090 -14.776 the serial number 109 110 111 112 113 114 115 116 101 the F1 under_X1 40.0 30.896 20.0 0.0 -20.149 -40.0 -52.985 -59.552 40.0 the F1 down_Y1 -13.284 -11.940 -8.806 -1.493 6.866 12.985 14.776 16.119 -13.284 the serial number 201 202 203 204 205 206 207 208 209 210 F2 up_X2 -48.507 -40.0 -30.0 -20.0 -10.0 10.0 20.0 30.0 40.0 44.179 F2 on_Y2 18.209 18.507 15.522 12.687 7.463 -3.284 -8.657 -12.090 -15.075 -16.269 serial number 210 211 212 213 214 215 216 217 218 201 F2 down_X2 40.000 30.000 21.343 10.000 -10.000 -20.000 -30.000 -40.000 -48.507 40.000 F2 down_Y2 -15.821 -14.478 -11.940 -7.164 3.284 8.955 13.582 16.418 18.209 -15.821 serial number 301 302 303 304 305 306 307 308 309 310 F3 on_X3 -35.522 -30.597 -25.0 -15.0 -5.0 5.0 15.0 25.0 30.597 35.821 F3 on_Y3 17.910 17.761 16.418 13.284 6.567 -0.597 -8.507 -15.224 -18.209 -19.701 serial number 310 311 312 313 314 315 316 317 318 301 F3 under_X3 35.821 30.597 25.0 15.0 5.0 -5.0 -15.0 -25.0 -30.597 -35.522 F3 down_Y3 -19.701 -19.403 -18.209 -14.179 -6.567 1.194 9.701 14.328 16.119 17.910

Among them, Fn up indicates the upper line of the nth profile, and Fn down indicates the lower line of the nth profile (n=1, 2, 3); Fn_Xn indicates the xn coordinate value of the curve on the profile Fn, Fn up _Yn indicates the yn coordinate value of the curve on the model line Fn (n=1, 2, 3); Fn under _Xn indicates the xn coordinate value of the curve on the model line Fn, and Fn _Yn indicates the yn coordinate of the curve on the model line Fn value (n=1, 2, 3).

Preferably: the six curve fitting equations of the three sections are as follows:

F1-F1 upper curve:

y ₁ = 4.139e-005 x ₁ ³ -0.0003387x ₁ ² -0.4065x ₁ + 1.731

F1-F1 lower curve:

y ₁ = 4.574e-005 x ₁ ³ -0.0006619x ₁ ² -0.4059x ₁ -1.201

F2-F2 upper curve:

y ₂ =8.084e-005x ₂ ³ -0.0004966x ₂ ² -0.5473x ₂ + 2.202

F2-F2 lower curve:

y ₂ =8.481e-005x ₂ ³ +0.001491x ₂ ² -0.54141x ₂ -1.947

F3-F3 upper curve:

y ₃ =0.0001776x ₃ ³ -0.003233x ₃ ² -0.7519x ₃ + 2.966

F3-F3 lower curve:

y ₃ =0.0002241x ₃ ³ +0.001285 x ₃ ² -0.8037x ₃ -2.674.

A shaft extension tubular pump turbine based on the above-mentioned low water head, including a pump turbine, a reversible motor, a flow channel, and a flow guide mechanism, and the flow channel includes a flow channel of the water inlet section and a flow channel of the guide vane section that are sequentially connected. , the runner chamber and the S-shaped draft tube flow channel; the reversible motor is arranged outside the S-shaped draft tube flow channel, the runner and the reversible motor are connected through the main shaft passing through the flow channel, and the power generation of the runner The inlet side of the working condition is provided with a diversion mechanism; at the same time, the runner is arranged in the runner chamber, and the diversion mechanism is arranged in the flow channel of the water inlet section and the flow channel of the guide vane section; the runner includes a runner hub, a discharge cone , the runner hub is evenly provided with a plurality of blades with symmetrical airfoil cross-section along the circumferential direction, and the drain cone is installed on the drain side of the runner hub; the initial placement angle of the blades is 39°, and the adjustment value is - Between 3° and 3°.

Preferably: the flow guide mechanism includes a guide body and movable guide vanes, the movable guide vanes are installed on the tail of the guide body, and the number of movable guide vanes is 8; the movable guide vanes are arranged in the flow channel of the guide vane section, and the guide vanes The fluid is arranged in the flow channel of the water inlet section and the guide vane section; the head of the guide body is spherical, the middle part is a cylinder, and the tail is a cone, and the cone angle is 18o. The head of the guide body, The middle part is arranged in the flow channel of the water inlet section, and the tail part of the guide body is arranged in the flow channel of the guide vane section.

Working principle of the present invention: the present invention is suitable for low water head pumped storage power stations. The pumped storage power station is a special form of hydropower station. The main difference from conventional hydropower stations is that it has two reservoirs, upper and lower, to recycle water. Its electromechanical equipment consists of two parts: pump turbine, and reversible motor. The pump-turbine has the dual functions of the water turbine and the water pump, and the reversible motor has the dual functions of the generator and the motor. Its operation can be divided into two working conditions, that is, the pump working condition and the water turbine working condition. The water pump working condition lifts the water from the lower reservoir to the upper reservoir, consumes electric energy, and converts the electric energy into the potential energy of the water in the upper reservoir; The water in the upper reservoir is put into the lower reservoir through the water turbine, and the potential energy of the water is converted into electrical energy to generate electrical energy. The energy conversion process of the two working conditions is shown in Figure 1. When other energy resources in the power system are sufficient, it pumps the excess capacity and electricity through the electric motor water pump to pump the water from the lower reservoir to the upper reservoir, and stores this part of the water in the form of potential energy. When other energy sources are insufficient, This part of the water is then used to generate electricity through the turbine generator to supplement the shortage of other energy sources to meet the stability of the system's power consumption, so that the cycle works continuously. The water guide mechanism changes the flow through the water turbine by changing the angle of the movable guide vane so as to change the output of power generation or the power suitable for pumping water, and at the same time fine-tune the installation angle (θ) of the runner according to the change of water head and flow to make the wheel rotate and move The guide vanes work together to ensure that the pump turbine operates in the high-efficiency zone.

Compared with the prior art, a low-head shaft-extension tubular pump-turbine of the present invention has the following beneficial effects: In order to ensure that the two-way efficiency of the pump-turbine is high, the rotor of the present invention adopts a symmetrical airfoil design. Good energy conversion efficiency can be obtained under both the pumping and pumping conditions. When generating power in the forward direction, the water flow flows through the movable guide vane and the runner through the water inlet channel, and finally is discharged to the downstream reservoir through the draft tube; the direction of the water flow is opposite when pumping water in the reverse direction. It is required that the runner can work in both directions, and that both forward and reverse work can have better energy conversion performance: forward power generation can convert water energy into as much electrical energy as possible; reverse pumping uses the remaining electrical energy to pump water to the upstream reservoir, to get as much water potential energy as possible. The energy conversion efficiency of the runner reaches more than 80% when it is generating electricity in the forward direction; it reaches more than 75% when it is working as a reverse pump. The unit is easy to install and maintain, and the overall cost of development in the power station is relatively cheap, which is about 20% lower than the cost of the bulb tubular unit.

Description of drawings

Accompanying drawing 1—the energy conversion diagram of pumping water and power generation two working conditions;

Accompanying drawing 2 - two-dimensional flow channel model diagram of the shaft-extension tubular pump-turbine;

Accompanying drawing 3 - Schematic diagram of the structure of the shaft-extension tubular pump turbine, Figure a is the structural diagram of the pump turbine, Figure b is the bottom view of Figure 5a, Figure c is the schematic diagram of the structure of the blades placed horizontally, and Figure d is the schematic diagram of the structure of the blades placed vertically;

Attached Figure 4 - Cross-sectional view of the runner blade, three sections F1~F3 of the blade space section,

Accompanying drawing 5, 6, 7 are the airfoil space molded lines on three sections of F1, F2, F3 in accompanying drawing 4 successively;

Among them: S1—inlet section flow channel, S2—guide vane section flow channel, S3—runner chamber, S4—s-type draft tube flow channel, 1—water inlet section, 2—diversion body, 3—flow diversion mechanism, 4—movable guide vane, 5—runner, 51-blade, 52-runner hub, 53-discharge cone, 6-s-type draft tube flow channel, 7—main shaft, 8—generator, 9—draft tube outlet Section, b ₂ - the minimum thickness of the blade, b ₁ - the maximum thickness of the blade.

Detailed ways

The accompanying drawing discloses a schematic structural view of a preferred embodiment of the present invention without limitation, and the technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings.

Example

In this embodiment, a blade of a low water head shaft extension tubular water pump turbine is shown in Fig. Section representation; at the same time, the middle section adopts a new type of line, which is composed of curves connected end to end at the upper and lower ends. The coordinate system is established with the center point of each type line of the three sections as the origin, x _1, x _{2 ,} x ₃ are the abscissas of each coordinate, y ₁ , y ₂ , y ₃ are the ordinates of each coordinate, and F1, F2, F3 respectively represent the three molded lines, then the position of the part point of the blade in the Cartesian coordinate system is shown in the following table Shown:

serial number 101 102 103 104 105 106 107 108 109 the F1 on_X1 -59.552 -50.0 -40.0 -20.0 0.0 20.0 30.896 40.0 52.836 the F1 on_Y1 16.119 15.821 14.627 9.851 1.642 -6.119 -9.851 -12.090 -14.776 the serial number 109 110 111 112 113 114 115 116 101 the F1 under_X1 40.0 30.896 20.0 0.0 -20.149 -40.0 -52.985 -59.552 40.0 the F1 down_Y1 -13.284 -11.940 -8.806 -1.493 6.866 12.985 14.776 16.119 -13.284 the serial number 201 202 203 204 205 206 207 208 209 210 F2 up_X2 -48.507 -40.0 -30.0 -20.0 -10.0 10.0 20.0 30.0 40.0 44.179 F2 on_Y2 18.209 18.507 15.522 12.687 7.463 -3.284 -8.657 -12.090 -15.075 -16.269 serial number 210 211 212 213 214 215 216 217 218 201 F2 down_X2 40.000 30.000 21.343 10.000 -10.000 -20.000 -30.000 -40.000 -48.507 40.000 F2 down_Y2 -15.821 -14.478 -11.940 -7.164 3.284 8.955 13.582 16.418 18.209 -15.821 serial number 301 302 303 304 305 306 307 308 309 310 F3 on_X3 -35.522 -30.597 -25.0 -15.0 -5.0 5.0 15.0 25.0 30.597 35.821 F3 on_Y3 17.910 17.761 16.418 13.284 6.567 -0.597 -8.507 -15.224 -18.209 -19.701 serial number 310 311 312 313 314 315 316 317 318 301 F3 under_X3 35.821 30.597 25.0 15.0 5.0 -5.0 -15.0 -25.0 -30.597 -35.522 F3 down_Y3 -19.701 -19.403 -18.209 -14.179 -6.567 1.194 9.701 14.328 16.119 17.910

Among them, Fn up indicates the upper line of the nth profile, and Fn down indicates the lower line of the nth profile (n=1, 2, 3); Fn_Xn indicates the xn coordinate value of the curve on the profile Fn, Fn up _Yn indicates the yn coordinate value of the curve on the model line Fn (n=1, 2, 3); Fn under _Xn indicates the xn coordinate value of the curve on the model line Fn, and Fn _Yn indicates the yn coordinate of the curve on the model line Fn value (n=1, 2, 3).

Preferably: the six curve fitting equations of the three sections are as follows:

F1-F1 upper curve:

y ₁ = 4.139e-005 x ₁ ³ -0.0003387x ₁ ² -0.4065x ₁ + 1.731

F1-F1 lower curve:

y ₁ = 4.574e-005 x ₁ ³ -0.0006619x ₁ ² -0.4059x ₁ -1.201

F2-F2 upper curve:

y ₂ =8.084e-005x ₂ ³ -0.0004966x ₂ ² -0.5473x ₂ + 2.202

F2-F2 lower curve:

y ₂ =8.481e-005x ₂ ³ +0.001491x ₂ ² -0.54141x ₂ -1.947

F3-F3 upper curve:

y ₃ =0.0001776x ₃ ³ -0.003233x ₃ ² -0.7519x ₃ + 2.966

F3-F3 lower curve:

y ₃ =0.0002241x ₃ ³ +0.001285 x ₃ ² -0.8037x ₃ -2.674

A low-head shaft-extending through-flow pump-turbine in this embodiment is shown in Figure 2, which includes a pump-turbine, a reversible motor, a flow channel, and a diversion mechanism. Guide vane section flow channel, runner chamber and S-shaped draft tube flow channel; the reversible motor is arranged outside the S-shaped draft tube flow channel, the water turbine includes a runner and movable guide vanes, and the runner and reversible The motor is connected through the main shaft transmission through the flow channel, and the reversible motor is located on one side of the runner, while the other side of the runner is provided with a guide mechanism; the guide mechanism includes a guide body and movable guide vanes, the The movable guide vane is installed on the guide body; at the same time, the runner is arranged in the runner chamber, the movable guide vane is arranged in the flow channel of the guide vane section, and the guide body is arranged in the flow channel of the water inlet section and the flow channel of the guide vane section;

As shown in Figure 3, the runner includes three parts: the blade, the hub of the runner, and the water discharge cone. The drain cone is installed; the shape of the blade is thick in the middle and thin on both sides; the initial placement angle θ of the blade is 39°, and the adjustment value is between -3° and 3°. The number of blades of the runner is 3. The blade of the runner is a new type of high-efficiency blade, which combines the advantages of the blades of the tubular water turbine and the blade of the tubular pump, so that the runner can be used as a water turbine and a water pump, and has good energy conversion performance. As shown in Figure 4, the runner blade described is a three-dimensional distorted surface in space, and its spatial characteristics can be represented by multiple sections. The key shape line can be fitted through the control points, and then the space surface is formed according to the key shape line. The minimum thickness of the blade is The ratio of b ₂ to the maximum thickness b ₁ is 0.28-0.35.

The present invention is only applicable to low-head pumped-storage power stations, with a water head of 5-20 meters and high-speed operation due to the small size of the runner, whose operating speed is 500rad/s-1000rad/s.

Its operation is divided into two working conditions, that is, the pump working condition and the turbine working condition. The pump working condition is that the pump turbine obtains kinetic energy through the motor to lift the water in the lower reservoir to the upper reservoir, consumes electrical energy, and converts the electrical energy into water in the upper reservoir. The working condition of the hydraulic turbine is that the water in the upper reservoir is converted into electrical energy through the hydraulic turbine to generate electrical energy, and then flows to the lower reservoir after passing through the hydraulic turbine. The invention not only can work in two directions, but also has better energy conversion performance. The energy conversion efficiency of the runner reaches more than 80% when the power is generated in the forward direction, and it reaches more than 75% when the water pump works in the reverse direction.

The preferred specific embodiments of the present invention described above in conjunction with the accompanying drawings are only used to illustrate the implementation of the present invention, rather than as a limitation to the foregoing invention purpose and the content and scope of the appended claims. Any simple modifications, equivalent changes and modifications made in the embodiments still belong to the technical and rights protection scope of the present invention.

Claims (4)

1. A low water head shaft extension tubular water pump turbine blade, characterized in that: the shape of the blade is thick in the middle and thin in both sides, and is a three-dimensional twisted curved surface in space, and its spatial characteristics are represented by three sections: upper, middle and lower; The section adopts a new type of line, which is composed of curves connected end to end at the upper and lower ends. The coordinate system is established with the center point of each line of the three sections as the origin, and x _1, x _{2, and} x ₃ are each The abscissa of the coordinates, y ₁ , y ₂ , and y ₃ are the ordinates of each coordinate, and F1, F2, and F3 respectively represent the three molded lines. The position of the blade part in the Cartesian coordinate system is shown in the table below: serial number 101 102 103 104 105 106 107 108 109 the F1 on_X1 -59.552 -50.0 -40.0 -20.0 0.0 20.0 30.896 40.0 52.836 the F1 on_Y1 16.119 15.821 14.627 9.851 1.642 -6.119 -9.851 -12.090 -14.776 the serial number 109 110 111 112 113 114 115 116 101 the F1 under_X1 40.0 30.896 20.0 0.0 -20.149 -40.0 -52.985 -59.552 40.0 the F1 down_Y1 -13.284 -11.940 -8.806 -1.493 6.866 12.985 14.776 16.119 -13.284 the serial number 201 202 203 204 205 206 207 208 209 210 F2 up_X2 -48.507 -40.0 -30.0 -20.0 -10.0 10.0 20.0 30.0 40.0 44.179 F2 on_Y2 18.209 18.507 15.522 12.687 7.463 -3.284 -8.657 -12.090 -15.075 -16.269 serial number 210 211 212 213 214 215 216 217 218 201 F2 down_X2 40.000 30.000 21.343 10.000 -10.000 -20.000 -30.000 -40.000 -48.507 40.000 F2 down_Y2 -15.821 -14.478 -11.940 -7.164 3.284 8.955 13.582 16.418 18.209 -15.821 serial number 301 302 303 304 305 306 307 308 309 310 F3 on_X3 -35.522 -30.597 -25.0 -15.0 -5.0 5.0 15.0 25.0 30.597 35.821 F3 on_Y3 17.910 17.761 16.418 13.284 6.567 -0.597 -8.507 -15.224 -18.209 -19.701 serial number 310 311 312 313 314 315 316 317 318 301 F3 under_X3 35.821 30.597 25.0 15.0 5.0 -5.0 -15.0 -25.0 -30.597 -35.522 F3 down_Y3 -19.701 -19.403 -18.209 -14.179 -6.567 1.194 9.701 14.328 16.119 17.910 Among them, the upper line of Fn means the upper line of the nth profile, and the lower line of Fn means the lower line of the nth profile (n=1, 2, 3); Fn_Xn indicates the xn coordinate value of the curve on the profile line Fn, and the upper line of Fn _Yn indicates the yn coordinate value of the curve on the model line Fn (n=1, 2, 3); Fn under _Xn indicates the xn coordinate value of the curve on the model line Fn, and Fn _Yn indicates the yn coordinate of the curve on the model line Fn value (n=1, 2, 3). 2. According to claim 1, the blade of the low-head shaft extension tubular water pump turbine is characterized in that: the equations after fitting of the six curves of the three sections are as follows: F1-F1 upper curve: y ₁ = 4.139e-005 x ₁ ³ -0.0003387x ₁ ² -0.4065x ₁ + 1.731 F1-F1 lower curve: y ₁ = 4.574e-005 x ₁ ³ -0.0006619x ₁ ² -0.4059x ₁ -1.201 F2-F2 upper curve: y ₂ =8.084e-005x ₂ ³ -0.0004966x ₂ ² -0.5473x ₂ + 2.202 F2-F2 lower curve: y ₂ =8.481e-005x ₂ ³ +0.001491x ₂ ² -0.54141x ₂ -1.947 F3-F3 upper curve: y ₃ =0.0001776x ₃ ³ -0.003233x ₃ ² -0.7519x ₃ + 2.966 F3-F3 lower curve: y ₃ =0.0002241x ₃ ³ +0.001285 x ₃ ² -0.8037x ₃ -2.674. 3. A low-head shaft-extending through-flow pump-turbine based on claim 1, characterized in that it includes a pump-turbine, a reversible motor, a flow channel, and a flow guide mechanism, and the flow channel includes water inlet sections that pass through in sequence Flow channel, guide vane section flow channel, runner chamber and S-shaped draft tube flow channel; the reversible motor is arranged outside the S-shaped draft tube flow channel, and the runner and reversible motor pass through the main shaft passing through the flow channel Transmission connection, and the inlet side of the power generation condition of the runner is provided with a flow guide mechanism; at the same time, the runner is set in the runner chamber, and the flow guide mechanism is set in the flow channel of the water inlet section and the flow channel of the guide vane section; the runner It includes a runner hub and a water discharge cone. The runner hub is evenly provided with a plurality of blades with symmetrical airfoils in the circumferential direction, and a water discharge cone is installed on the water discharge side of the runner hub; the initial placement angle of the blades is is 39°, and the adjustment value is between -3° and 3°. 4. According to claim 3, the low-head shaft-extension tubular flow pump-turbine is characterized in that: the flow guide mechanism includes a guide body and a movable guide vane, the movable guide vane is installed on the tail of the guide body, and the movable guide vane The number of guide vanes is 8; the movable guide vane is arranged in the flow channel of the guide vane section, and the guide body is arranged in the flow channel of the water inlet section and the guide vane section flow channel; the head of the guide body is spherical, the middle part is a cylinder, and the tail is Conical body, and the cone angle is 18o, the head and middle part of the guiding body are arranged in the flow channel of the water inlet section, and the tail of the guiding body is arranged in the flow channel of the guide vane section.

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