Single-impeller water wheel pump suitable for variable flow rate environment and control method thereof

Abstract

A single-impeller water wheel pump suitable for variable flow rate environment and a control method thereof, comprising a Venturi tube, a propeller-type impeller and a centrifugal pump group coaxially arranged with the propeller-type impeller arranged in sequence, and the propeller-type impeller is externally provided with a water passing cover connected with the Venturi tube and the centrifugal pump group; the propeller-type impeller is provided with an output shaft for driving the centrifugal pump group to rotate and a plurality of adjusting blades for driving the output shaft to rotate, and the output shaft is internally provided with a rotating shaft for synchronously controlling the rotating angle of the plurality of adjusting blades; compared with the prior art, by arranging the adjusting blades with adjustable angle, the different adjusting blade angle switching under different flow rate states can be realized, and the wave-shaped protrusions are formed at the leading edges of the adjusting blades, so that the flow separation can be effectively inhibited, the wake vortex amount at the impeller outlet is reduced, the pressure pulsation is reduced, and the waste of water flow energy is also reduced.

Description

Technical Field

[0001] This invention relates to the field of water turbine pump technology, specifically to a single-impeller water turbine pump suitable for variable flow velocity environments and its control method. Background Technology

[0002] A water turbine pump is a hydraulic machine that is directly driven by water energy, requiring no electricity or fuel. It is widely used for irrigation, water supply, and small-scale power generation in remote mountainous areas. Existing water turbine pump technology is mainly divided into two categories: one is the traditional impulse or reaction water turbine pump, and the other is the flow velocity water turbine pump developed in recent years.

[0003] Among them, the flow velocity type water turbine pump is a water lifting device that directly utilizes the kinetic energy of the flow velocity in natural rivers and streams. The flow velocity type water turbine pump does not require dam construction or power consumption, and is particularly suitable for plains or gentle slope areas with low water head, shallow water flow, and large flow.

[0004] Chinese patent CN114893408A discloses a low-head flow rate water turbine pump, including a tapered and expanding throat, a booster unit, a speed transmission component, and a pump body unit. The tapered and expanding throat is connected to one side of the booster unit, and the speed transmission component is connected to the other side of the booster unit. A drainage channel is formed between the speed transmission component and the booster unit. The rotating shaft inside the booster unit is connected to the output shaft of the pump body unit via the speed transmission component. Fluid is transported to the booster unit through the tapered and expanding throat and output from the drainage channel, so that the rotating shaft inside the booster unit can rotate around its own axis to drive the pump body unit to draw water.

[0005] The aforementioned water turbine pump drives the rotation of the water turbine by setting up a pressure booster component with a multi-stage blade structure. However, under the action of the multi-stage blade structure, the resistance inside the water turbine pump is easily increased, resulting in the formation of vortex zones between the multi-stage blades, which wastes energy. At the same time, the multi-stage blade structure has a large number of parts, requires high assembly precision, has a high probability of failure, and is difficult to maintain. Summary of the Invention

[0006] The present invention aims to overcome the defects in the prior art and provide a single impeller water pump and its control method that are simple in structure, highly efficient in operation, and compact in structure and suitable for variable flow velocity environments.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a single-impeller water pump suitable for variable flow velocity environments, comprising a Venturi tube, a propeller impeller, and a centrifugal pump unit coaxially arranged with the propeller impeller in sequence; the propeller impeller is provided with a water shroud connecting the Venturi tube and the centrifugal pump unit; the propeller impeller is provided with an output shaft for driving the centrifugal pump unit to rotate and a plurality of adjusting blades for driving the output shaft to rotate; the output shaft is provided with a rotating shaft for synchronously controlling the rotation angle of the plurality of adjusting blades; the propeller impeller is provided with a driving bevel gear that rotates synchronously with the rotating shaft and a driven bevel gear that rotates synchronously with the adjusting blades; the driving bevel gear meshes with the driven bevel gear, and the rotation of the driven bevel gear drives the adjusting blades to rotate; the leading edge of the adjusting blades has a wavy protrusion, and the trailing edge of the adjusting blades has a serrated structure; the centrifugal pump unit is driven by the output shaft, and a generator driven by the output shaft is also installed at the tail of the centrifugal pump unit.

[0008] As a preferred embodiment of the present invention, the impeller includes an adjustment seat, a plurality of adjustment blades are circumferentially mounted on the adjustment seat, an output shaft is connected to both ends of the adjustment seat, and the output shaft rotates synchronously with the adjustment seat, and the rotation shaft passes through the adjustment seat.

[0009] As a preferred embodiment of the present invention, a connecting column passing through the adjusting seat is provided between the driven bevel gear and the adjusting blade. The connecting column, the driven bevel gear and the adjusting blade rotate synchronously. A rotary encoder for identifying the rotation angle of the adjusting blade is installed on the connecting column.

[0010] As a preferred embodiment of the present invention, a planetary gearbox connected to the output shaft is provided between the centrifugal pump unit and the impeller, and the planetary gearbox and the generator are switchably connected via an electromagnetic clutch.

[0011] As a preferred embodiment of the present invention, the planetary gearbox includes a synchronously rotating sun gear, planet gears, a planet carrier, and a ring gear. The sun gear is connected to the end of the rotating shaft, the planet carrier is connected to the input shaft of the centrifugal pump unit, and the ring gear is connected to the generator via an electromagnetic clutch.

[0012] As a preferred embodiment of the present invention, the output shaft end is disposed toward the Venturi tube, the output shaft end is provided with a water-passing grid to facilitate water flow, the water-passing grid abuts against the Venturi tube, and the output shaft is provided with a drive motor for driving the rotating shaft to rotate.

[0013] As a preferred embodiment of the present invention, the front end of the Venturi tube is provided with a vortex sedimentation device and a fish barrier arranged sequentially along the direction of the Venturi tube inlet. The vortex sedimentation device is located between the Venturi tube and the fish barrier. The Venturi tube includes a converging section, a throat section and a diffuser section connected in sequence. The converging section is provided corresponding to the vortex sedimentation device, the diffuser section is provided corresponding to the propeller impeller, and a pressure sensor for detecting real-time water kinetic energy pressure is provided in the throat section.

[0014] As a preferred embodiment of the present invention, the centrifugal pump set is equipped with a return pipe and an outlet pipe. The return pipe is connected to the inlet of the venturi tube, and a return control valve is provided on the return pipe, while a flow sensor is provided on the outlet pipe.

[0015] As a preferred embodiment of the present invention, the relative amplitude of the wavy protrusions is 0.02 to 0.05 times the chord length, and the relative spacing of the wavy protrusions is 0.08 to 0.15 times the chord length.

[0016] A control method for a single-impeller water turbine pump suitable for variable flow velocity environments, based on a single-impeller water turbine pump suitable for variable flow velocity environments, includes the following steps:

[0017] Step S1: Obtain the synergistic relationship curves of water kinetic energy pressure, pumping rate, blade angle adjustment, and backflow control valve outputs based on a finite number of experiments;

[0018] Step S2: Real-time detection of water kinetic energy pressure using a pressure sensor and real-time monitoring of water flow rate using a flow sensor;

[0019] Step S3: Based on the data from Step S2, compare it with the synergy curve in Step S1 to obtain the corresponding blade angle data;

[0020] Step S4: Synchronously adjust the angle of several adjusting blades by rotating the shaft, and adjust the opening of the return flow control valve according to the angle of the adjusting blades identified by the rotary encoder.

[0021] Step S5: When the input power exceeds the pumping requirement, engage the electromagnetic clutch to generate electricity; when the input power is insufficient, disengage the electromagnetic clutch and the centrifugal pump set pumps water at full capacity.

[0022] Compared to existing technologies, by setting adjustable blades, different blade angles can be switched under different flow velocities. In addition, the wavy protrusions formed at the leading edge of the blades can effectively suppress flow separation, reduce the wake vortex at the impeller outlet, reduce pressure pulsation, and reduce the waste of water flow energy.

[0023] By setting meshing active and driven bevel gears to adjust the angle of the regulating blades, the regulating blades can be effectively adjusted within the required adjustment range, enabling the impeller itself to efficiently absorb water energy at different flow rates and avoiding the blockage or "stall" phenomenon that occurs when the fixed blades are at high flow rates. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 This is an exploded view of the present invention;

[0026] Figure 3 This is a schematic diagram of the usage state;

[0027] Figure 4 This is a schematic diagram of the adjustable blade structure;

[0028] Figure 5 This is a schematic diagram showing the connection between the planetary gearbox, centrifugal pump unit, and electromagnetic clutch.

[0029] Figure 6 This is a schematic diagram of the adjustment seat;

[0030] Figure 7 This is a schematic diagram of a propeller impeller.

[0031] Figure 8 This is a flowchart of the present invention;

[0032] Figure 9 This is a comparison chart of the efficiency of the present invention and fixed structure blades;

[0033] Reference numerals: Venturi tube 1, contraction section 11, throat section 12, diffuser section 13, impeller 2, adjusting seat 21, adjusting blade 22, wavy protrusion 221, sawtooth structure 222, output shaft 23, drive motor 231, rotating shaft 24, driving bevel gear 25, driven bevel gear 26, connecting column 27, rotary encoder 28, water-passing grid 29, centrifugal pump set 3, return pipe 31, outlet pipe 32, return control valve 33, flow sensor 34, generator 4, planetary gearbox 5, sun gear 51, planetary carrier 52, gear ring 53, cyclone sedimentation device 6, fish barrier 7, water-passing cover 8, electromagnetic clutch 9. Detailed Implementation

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] like Figure 1-9As shown, a single-impeller water pump suitable for variable flow velocity environments includes a Venturi tube 1, a propeller impeller 2, and a centrifugal pump assembly 3 arranged sequentially. The propeller impeller 2 is externally equipped with a water-passing cover 8 connecting the Venturi tube 1 and the centrifugal pump assembly 3. The propeller impeller 2 has an output shaft 23 for driving the centrifugal pump assembly 3 and several adjusting blades 22 for driving the output shaft 23 to rotate. The output shaft 23 contains a rotating shaft 24 for synchronously controlling the rotation angle of the adjusting blades 22. The impeller 2 is equipped with a driving bevel gear 25 that rotates synchronously with the rotating shaft 24 and a driven bevel gear 26 that rotates synchronously with the adjusting blade 22. The driving bevel gear 25 and the driven bevel gear 26 mesh with each other, and the rotation of the driven bevel gear 26 drives the adjusting blade 22 to rotate. The leading edge of the adjusting blade 22 has a wave-shaped protrusion 221, and the trailing edge of the adjusting blade 22 has a serrated structure 222. The centrifugal pump set 3 is driven by the output shaft 23, and a generator 4 driven by the output shaft 23 is also installed at the tail of the centrifugal pump set 3.

[0036] The angle of the adjusting blade 22 can be continuously adjusted within a certain range (5°-25°). The airfoil of the adjusting blade 22 is biomimetic optimized. The surface of the adjusting blade 22 is coated with an anti-wear coating, which can be sprayed with tungsten carbide to increase the service life of the adjusting blade 22.

[0037] During the operation of the propeller impeller 2, the rotating shaft 24 rotates synchronously with the output shaft 23. When the rotating shaft 24 rotates relative to the output shaft 23, the rotating shaft 24 drives the rotation of the drive bevel gear 25 to adjust the angle of several adjusting blades 22.

[0038] The water shroud 8 is installed outside the impeller 2. When water flows through the venturi tube 1, it flows into the water shroud 8. The water shroud 8 is used to set the impeller 2 in a relatively closed environment so that it can be pumped by the centrifugal pump set 3.

[0039] The impeller 2 includes an adjustment seat 21, several adjustment blades 22 are circumferentially mounted on the adjustment seat 21, an output shaft 23 is connected to both ends of the adjustment seat 21 and the output shaft 23 rotates synchronously with the adjustment seat 21, and a rotating shaft 24 is set through the adjustment seat 21.

[0040] A connecting post 27 is provided between the driven bevel gear 26 and the adjusting blade 22, passing through the adjusting seat 21. The connecting post 27, the driven bevel gear 26 and the adjusting blade 22 rotate synchronously. A rotary encoder 28 for identifying the rotation angle of the adjusting blade 22 is installed on the connecting post 27.

[0041] A planetary gearbox 5 connected to the output shaft 23 is provided between the centrifugal pump unit 3 and the impeller 2. The planetary gearbox 5 and the generator 4 are connected in a switchable manner via an electromagnetic clutch 9.

[0042] Under the action of the planetary gearbox 5, the rotation of the impeller 2 is also simultaneously output to the centrifugal pump group 3 and the generator 4, and under the action of the electromagnetic clutch 9, the rotation output of the impeller 2 can be received and controlled.

[0043] The planetary gearbox 5 includes a synchronously rotating sun gear 51, planet gears, planet carrier 52, and ring gear 53. The sun gear 51 is connected to the end of the rotating shaft 24, the planet carrier 52 is connected to the input shaft of the centrifugal pump set 3, and the ring gear 53 is connected to the generator 4 via an electromagnetic clutch 9.

[0044] Multiple planetary gears are arranged around the sun gear 51, and the sun gear 51 is fixedly connected to the output shaft 23. Under the rotation of the output shaft 23, the sun gear 51 is driven to rotate synchronously. The planetary gears mesh with the sun gear 51, thereby driving the rotation of the planetary gears and the movement of the planetary gears within the gear ring 53 under the rotation of the sun gear 51. The planet carrier 52 is connected to the multiple planetary gears. Under the rotation and movement of the planetary gears, the planet carrier 52 is driven to rotate, while the gear ring 53 rotates through the movement of the planetary gears. The rotation of the gear ring 53 is output to the electromagnetic clutch 9.

[0045] The generator 4 receives the rotation of the gear ring 53 through the electromagnetic clutch 9, and the generator 4 is connected to the battery for energy storage via the rectifier energy storage module.

[0046] The output shaft 23 is positioned with its end facing the venturi tube 1. The output shaft 23 is provided with a water-passing grid 29 to facilitate water flow. The water-passing grid 29 abuts against the venturi tube 1. The output shaft 23 is provided with a drive motor 231 for driving the rotating shaft 24 to rotate.

[0047] The end of the water-passing grid 29 abuts against the interior of the diffuser section 13 of the venturi tube 1. The water-passing grid 29 is a hollow frustum structure formed at the end of the output shaft 23. The middle part of the water-passing grid 29 is used to receive the water flow out of the diffuser section 13. The water flow enters the water-passing cover 8 through the grid holes on the water-passing grid 29.

[0048] The drive motor 231 can be connected to the rotating shaft 24 via gears. Under the action of the drive motor 231 driving the gear to rotate, the gear sleeved on the rotating shaft 24 will rotate, thereby driving the rotating shaft 24 to rotate. The rotation of the rotating shaft 24 drives the driving bevel gear 25 and the driven bevel gear 26 to rotate synchronously, thereby controlling the rotation of the adjusting blade 22. At the same time, the rotation encoder 28 identifies the amount of rotation of the adjusting blade 22 in real time and feeds it back to the drive motor 231 to control the amount of rotation of the rotating shaft 24.

[0049] Under the action of gear connection between rotating shaft 24 and drive motor 231, when drive motor 231 is stationary, the gear meshing achieves self-locking between rotating shaft 24 and drive motor 231, thereby satisfying the synchronous rotation of rotating shaft 24, drive motor 231 and output shaft 23.

[0050] The front end of the Venturi tube 1 is provided with a vortex sedimentation device 6 and a fish barrier 7 arranged sequentially along the inlet direction of the Venturi tube 1. The vortex sedimentation device 6 is located between the Venturi tube 1 and the fish barrier 7. The Venturi tube 1 includes a converging section 11, a throat section 12 and a diffuser section 13 connected in sequence. The converging section 11 is provided corresponding to the vortex sedimentation device 6, and the diffuser section 13 is provided corresponding to the impeller 2. A pressure sensor for detecting real-time water kinetic energy pressure is provided in the throat section 12.

[0051] The contraction angle of the contraction section 11 is 22°, the diffusion angle of the diffusion section 13 is 8°, the throat section 12 has a diameter of 0.2m, and a pressure sensor is installed in the throat section 12.

[0052] As the water flows into the contraction section 11, the flow area decreases sharply. According to the continuity equation (A1v1=A2v2), the flow velocity is forcibly increased, reaching its peak at the throat section 12. Based on Bernoulli's principle, the static pressure decreases as the kinetic energy increases, forming a significant low-pressure zone in the throat section 12, which can be used to pump water. After passing through the throat section 12, the water enters the diffuser section 13, where the flow area increases, the flow velocity drops, and the static pressure partially increases. By combining the pressure sensor inside the throat section 12 with the pipe diameter of the throat section 12, the water flow rate can be calculated.

[0053] The cyclone separator 6 is used to screen the water flow entering the venturi tube 1. The cyclone separator 6 includes a tangential inlet, spiral guide vanes and a conical settling chamber. Under the action of the cyclone separator 6, centrifugal force is used to efficiently separate and remove inorganic solid particles (sand, gravel, slag, etc.) with higher density in the water flow, so as to protect the stable use of the subsequent venturi tube 1 and reduce the interference of foreign objects on the impeller 2.

[0054] The fish barrier 7 is used to block fish and shrimp in the water flow. By forming a grid structure, the fish barrier 7 prevents fish and shrimp in the water flow from entering the Venturi tube 1 and the impeller 2 and affecting the use of the overall structure. At the same time, the fish barrier 7 is provided with fish guide channels and low-frequency vibration fish driveers on both sides through the grid structure.

[0055] The centrifugal pump set 3 is equipped with a return pipe 31 and an outlet pipe 32. The return pipe 31 is connected to the inlet of the venturi tube 1, and a return control valve 33 is provided on the return pipe 31. A flow sensor 34 is provided on the outlet pipe 32.

[0056] The relative amplitude of the wavy protrusions 221 is 0.02 to 0.05 times the chord length, and the relative spacing of the wavy protrusions 221 is 0.08 to 0.15 times the chord length.

[0057] The wave-shaped protrusion 221 is set at the leading edge of the regulating blade 22 (0-5% of the chord length), with an amplitude of 0.3 mm (0.03 times the chord length) and a wavelength of 1 mm (0.1 times the chord length). This structure can increase the lift coefficient by 8% to 12% and reduce the drag coefficient by 5% to 7% at large angles of attack (10°~20°), and effectively suppress trailing edge vortex shedding.

[0058] Figure 9 The MAP table in the model was calibrated through model tests, so that the propeller impeller 2 operated near the point of highest hydraulic efficiency at different flow velocities.

[0059] A control method for a single-impeller water turbine pump suitable for variable flow velocity environments, characterized by comprising the following steps:

[0060] Step S1: Obtain the correlation curve of water kinetic energy pressure, pumping rate, adjusting blade 22 angle and backflow control valve 33 as outputs based on a limited number of experiments;

[0061] Step S2: The pressure of the water flow energy is detected in real time by the pressure sensor, and the water flow rate is monitored in real time by the flow sensor 34;

[0062] Step S3: Based on the data from Step S2, compare it with the synergy curve in Step S1 to obtain the corresponding adjustment blade angle data;

[0063] Step S4: Simultaneously adjust the angles of several adjusting blades 22 by rotating shaft 24, and identify the angles of adjusting blades 22 according to the rotary encoder 28, while adjusting the opening of the return flow control valve 33.

[0064] Step S5: When the input power exceeds the pumping requirement, engage the electromagnetic clutch 9 and the generator 4 generates electricity. When the input power is insufficient, disengage the electromagnetic clutch 9 and the centrifugal pump set 3 pumps water at full capacity.

[0065] Based on actual results, under low flow rate conditions (2~4m / s), the angle of the adjusting blade 22 is 0°-5°. When the adjusting blade 22 is adjusted to this angle, the electromagnetic clutch 9 is disengaged, the return control valve 33 is engaged, and the device pumps water at full capacity. The measured pumping flow rate is 85~100m³ / h, and the overall pumping efficiency is 68.5%.

[0066] Under medium to high flow rate conditions (4~7m / s), the angle of the blade 22 is adjusted to 10°-20° to increase the torque absorption capacity. The electromagnetic clutch 9 is engaged, and the generator 4 generates electricity. At the same time, the backflow control valve 33 is opened to a certain extent, so that the flow rate of the outlet pipe 32 is stabilized at 100m³ / h. The measured output power of the generator 4 is 2~8kW, and the comprehensive utilization rate is 89%~91%.

[0067] Under high flow rate conditions (7~9m / s), the angle of the adjusting blade 22 is set to 25° of the maximum angle, the electromagnetic clutch 9 remains engaged, the generator 4 is fully loaded at 10kW, and the opening of the return flow control valve 33 is increased to 60%~80% to divert excess water, with a comprehensive utilization rate of about 91%.

[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention; therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0069] Although this document uses numerous reference numerals from the figures, such as Venturi tube 1, contraction section 11, throat section 12, diffuser section 13, impeller 2, adjusting seat 21, adjusting blade 22, wavy protrusion 221, serrated structure 222, output shaft 23, drive motor 231, rotating shaft 24, driving bevel gear 25, driven bevel gear 26, connecting column 27, rotary encoder 28, water-passing grid 29, centrifugal pump set 3, return pipe 31, outlet pipe 32, return control valve 33, flow sensor 34, generator 4, planetary gearbox 5, sun gear 51, planetary carrier 52, gear ring 53, cyclone sedimentation device 6, fish barrier 7, water-passing cover 8, electromagnetic clutch 9, etc., the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A single-impeller water pump suitable for variable flow velocity environments, comprising a venturi tube (1), a propeller impeller (2), and a centrifugal pump assembly (3) coaxially arranged with the propeller impeller (2), wherein the propeller impeller (2) is provided with a water shroud (8) connecting the venturi tube (1) and the centrifugal pump assembly (3); characterized in that, The impeller (2) is provided with an output shaft (23) for driving the centrifugal pump group (3) to rotate and a plurality of adjusting blades (22) for driving the output shaft (23) to rotate. The output shaft (23) is provided with a rotating shaft (24) for synchronously controlling the rotation angle of the plurality of adjusting blades (22). The impeller (2) is provided with a driving bevel gear (25) that rotates synchronously with the rotating shaft (24) and a driven bevel gear (26) that rotates synchronously with the adjusting blades (22). The driving bevel gear (25) and the driven bevel gear (26) mesh with each other. The rotation of the driven bevel gear (26) drives the adjusting blades (22) to rotate. The leading edge of the adjusting blades (22) has a wave-shaped protrusion (221), and the trailing edge of the adjusting blades (22) has a sawtooth structure (222). The centrifugal pump group (3) is driven by the output shaft (23), and a generator (4) driven by the output shaft (23) is also installed at the tail of the centrifugal pump group (3).

2. A single-impeller water pump suitable for variable flow velocity environments according to claim 1, characterized in that, The impeller (2) includes an adjustment seat (21), several adjustment blades (22) are circumferentially mounted on the adjustment seat (21), the output shaft (23) is connected to both ends of the adjustment seat (21), and the output shaft (23) rotates synchronously with the adjustment seat (21), and the rotating shaft (24) passes through the adjustment seat (21).

3. A single-impeller water pump suitable for variable flow velocity environments according to claim 1, characterized in that, A connecting post (27) is provided between the driven bevel gear (26) and the adjusting blade (22) through the adjusting seat (21). The connecting post (27), the driven bevel gear (26) and the adjusting blade (22) rotate synchronously. A rotary encoder (28) for identifying the rotation angle of the adjusting blade (22) is installed on the connecting post (27).

4. A single-impeller water pump suitable for variable flow velocity environments according to claim 1, characterized in that, The centrifugal pump unit (3) and the impeller (2) are provided with a planetary gearbox (5) connected to the output shaft (23). The planetary gearbox (5) and the generator (4) are connected in a switchable manner through an electromagnetic clutch (9).

5. A single-impeller water pump suitable for variable flow velocity environments according to claim 4, characterized in that, The planetary gearbox (5) includes a synchronously rotating sun gear (51), planet gears, planet carrier (52) and gear ring (53). The sun gear (51) is connected to the end of the rotating shaft (24), the planet carrier (52) is connected to the input shaft of the centrifugal pump group (3), and the gear ring (53) is connected to the generator (4) through an electromagnetic clutch (9).

6. A single-impeller water pump suitable for variable flow velocity environments according to claim 1, characterized in that, The output shaft (23) is positioned with its end facing the venturi tube (1). The output shaft (23) is provided with a water-passing grid (29) to facilitate water flow. The water-passing grid (29) abuts against the venturi tube (1). The output shaft (23) is provided with a drive motor (231) for driving the rotating shaft (24) to rotate.

7. A single-impeller water pump suitable for variable flow velocity environments according to claim 1, characterized in that, The front end of the Venturi tube (1) is provided with a vortex sedimentation device (6) and a fish barrier (7) arranged sequentially along the inlet direction of the Venturi tube (1). The vortex sedimentation device (6) is located between the Venturi tube (1) and the fish barrier (7). The Venturi tube (1) includes a converging section (11), a throat section (12) and a diffuser section (13) connected in sequence. The converging section (11) is provided corresponding to the vortex sedimentation device (6), and the diffuser section (13) is provided corresponding to the impeller (2). A pressure sensor for detecting real-time water kinetic energy pressure is provided in the throat section (12).

8. A single-impeller water pump suitable for variable flow velocity environments according to claim 1, characterized in that, The centrifugal pump set (3) is equipped with a return pipe (31) and an outlet pipe (32). The return pipe (31) is connected to the inlet of the venturi pipe (1), and a return control valve (33) is provided on the return pipe (31), and a flow sensor (34) is provided on the outlet pipe (32).

9. A single-impeller water pump suitable for variable flow velocity environments according to claim 1, characterized in that, The relative amplitude of the wave-shaped protrusions (221) is 0.02 to 0.05 times the chord length, and the relative spacing of the wave-shaped protrusions (221) is 0.08 to 0.15 times the chord length.

10. A control method for a single-impeller water turbine pump suitable for variable flow velocity environments, based on the single-impeller water turbine pump suitable for variable flow velocity environments as described in any one of claims 1-9, characterized in that, Includes the following steps: Step S1: Obtain the synergistic relationship curves of water kinetic energy pressure, pumping volume, adjusting blade (22) angle and reflux control valve (33) as outputs based on a limited number of experiments; Step S2: Real-time detection of water kinetic energy pressure by pressure sensor and real-time monitoring of water flow rate by flow sensor (34); Step S3: Based on the data from step S2, compare the correlation curve in step S1 to obtain the corresponding adjustment blade (22) angle data; Step S4: Simultaneously adjust the angles of several adjusting blades (22) by rotating shaft (24), and identify the angles of the adjusting blades (22) according to the rotating encoder (28), while adjusting the opening of the return flow control valve (33); Step S5: When the input power exceeds the pumping requirement, engage the electromagnetic clutch (9) and the generator (4) generates electricity. When the input power is insufficient, disengage the electromagnetic clutch (9) and the centrifugal pump set (3) pumps water at full capacity.

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