Water turbine system based on cavitation erosion resistance and active vibration suppression

Abstract

The invention discloses a water turbine system based on cavitation erosion resistance and active vibration suppression, which comprises a water turbine, an active vibration suppression device, a sensor module, an intelligent regulation and control unit and blades arranged in the water turbine, bionic micro-groove arrays are distributed on the pressure surfaces of the blades, the active vibration suppression device is mounted on a main shaft, and the sensor module is mounted on the main shaft. The active vibration suppression device is used for actively suppressing vibration generated by the spindle when the water turbine works, the sensor module is arranged on the spindle and used for detecting spindle vibration data, and the intelligent regulation and control unit is electrically connected with the water turbine, the sensor module and the active vibration suppression device. The control module is used for controlling operation parameters of the active vibration suppression device and the water turbine according to vibration data acquired by the sensor module. Through integration of the composite anti-cavitation structure, the active vibration suppression device and the intelligent regulation and control technology, the problems of cavitation damage and low-frequency vibration are solved, the service life of equipment is remarkably prolonged, and the operation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to a water turbine system based on anti-cavitation and active vibration suppression, belonging to the technical field of hydropower generation. Background Art

[0002] A water turbine system is a power mechanical system that converts the energy of water flow into rotational mechanical energy. Most water turbine systems are installed in hydropower stations to drive generators to generate electricity. In a hydropower station, water in the upstream reservoir is led to the water turbine through a water inlet pipe, pushing the runner of the water turbine to rotate and driving the generator to generate electricity. The water that has done work is then discharged downstream through the tail water pipe. The higher the head and the larger the flow rate, the greater the output power of the water turbine.

[0003] The following technical defects exist in traditional water turbine systems: severe cavitation damage. Due to the phenomenon that the flow velocity of the water flowing through the water turbine suddenly increases at some positions, causing the pressure at that position to locally decrease, it will damage the water turbine blades. The existing runner blade surfaces usually adopt stainless steel surfacing or spraying hard alloys, and the cavitation phenomenon makes the coating easy to peel off. Usually, the average annual cavitation depth can reach 3 - 5 mm, and frequent shutdowns are required for repair; at the same time, it is difficult to suppress the low-frequency vibration of the water turbine. The vortex band in the draft tube causes low-frequency vibration of 0.5 - 10 Hz, and traditional mechanical dampers cannot effectively suppress it, resulting in a shortened bearing life by more than the above. The existing technology lacks a systematic solution for the coordinated optimization of materials, structures, and controls, resulting in a short lifespan, low efficiency, and high maintenance costs of water turbines. Therefore, we propose a water turbine system based on anti-cavitation and active vibration suppression. Summary of the Invention

[0004] The purpose of the present invention is to provide a water turbine system based on anti-cavitation and active vibration suppression, which solves the problems of cavitation damage and low-frequency vibration through the integration of a composite anti-cavitation structure, an active vibration suppression device, and intelligent control technology, and significantly extends the equipment lifespan and improves the operating efficiency.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions: A water turbine system based on anti-cavitation and active vibration suppression, comprising:

[0006] A water turbine, the water turbine is respectively connected to the upstream water source and the downstream reservoir through a water inlet pipe and a water outlet pipe, one end of the output end of the water turbine is connected to one end of a main shaft, and the other end of the main shaft is successively connected to a speed increaser box and a generator;

[0007] Blades arranged inside the water turbine, on the pressure surface of the blades, a bionic micro-groove array is distributed, imitating the micro-groove texture of shark skin, optimizing the blade flow channel, reducing turbulent separation, and thus suppressing the generation of cavitation effects;

[0008] An active vibration suppression device, which is installed on the main shaft and used to actively suppress the vibration generated by the main shaft during the operation of the water turbine. The active vibration suppression device uses controllable magnetic field damping to suppress low-frequency vibrations of 0.5 - 10 Hz and can be actively regulated;

[0009] A sensor module, which is arranged on the main shaft and used to detect the vibration data of the main shaft;

[0010] An intelligent control unit, which is electrically connected to the water turbine, the sensor module, and the active vibration suppression device respectively, and is used to control the operating parameters of the active vibration suppression device and the water turbine according to the vibration data obtained by the sensor module. The intelligent control unit can use an industrial computer to obtain the low-frequency vibration information of the main shaft collected by the sensor module and perform analysis and calculation based on the original operation data of the hydropower electric control system to adjust the operating parameters of the dynamic vibration suppression device.

[0011] The aforementioned water turbine system based on cavitation resistance and active vibration suppression. The water turbine further includes a housing and a guide bearing arranged inside the housing. A rotating shaft is installed on the guide bearing. One end of the rotating shaft is connected to the main shaft, and the other end of the rotating shaft extends into the inner cavity of the housing and is provided with a plurality of blades distributed in a ring shape. A guide vane is arranged at the water inlet end of the housing. The guide vane is connected with a control link, and the control link is electrically connected to the intelligent control unit. The intelligent control unit can adjust the guide vane opening based on real-time flow data to destroy the formation conditions of the draft tube vortex band.

[0012] The aforementioned water turbine system based on cavitation resistance and active vibration suppression. The upper and lower sides of the blade are the water inlet edge and the water outlet edge respectively. The bionic microgroove array is composed of a plurality of bionic grooves extending from the water inlet edge to the water outlet edge. The cross-section of the bionic groove is trapezoidal. The inclined surfaces on both sides of the trapezoidal bionic groove can guide the water flow into the bionic groove gently, reduce the turbulent vortices generated by flow separation, and a stable secondary eddy current is formed at the bottom of the trapezoidal cross-section of the bionic groove, reducing the mainstream shear stress and suppressing the initial cavitation.

[0013] The aforementioned water turbine system based on cavitation resistance and active vibration suppression. The long side width of the bionic groove is 80 - 100 μm, the short side width is 50 - 70 μm, the depth is 20 - 30 μm, and the spacing is 200 - 300 μm.

[0014] The aforementioned water turbine system based on cavitation resistance and active vibration suppression. The water inlet edge of the blade is arc-shaped and the radius of the water inlet edge a gradually increases from the inside to the outside. The inner end of the water inlet edge gradually descends while the outer end gradually ascends, which can guide the water flow towards the inner hub direction of the blade, reduce the low-pressure area on the back of the water inlet edge of the blade, and improve the water flow impact near the front water inlet edge, which is beneficial to the improvement of cavitation performance.

[0015] The aforementioned water turbine system based on cavitation resistance and active vibration suppression, on the surface of the blade is provided with a laser cladding cobalt-based alloy layer, which significantly improves surface wear resistance and chemical corrosion resistance, can effectively resist the impact of cavitation collapse, and prolongs the service life.

[0016] The aforementioned water turbine system based on cavitation resistance and active vibration suppression, the active vibration suppression device includes a fixed housing and a connecting bearing installed on the main shaft. The connecting bearing penetrates the fixed housing and has a gap with the fixed housing. A permanent magnet is arranged around the outer side wall of the connecting bearing. The outer surface of the permanent magnet is coated with an inner magnetic conductive plate. The side wall of the inner cavity of the fixed housing is distributed around the center line of the main shaft with exciting coils. The exciting coils are electrically connected to the intelligent control unit. The surface of the exciting coils is coated with an outer magnetic conductive plate. The inner magnetic conductive plate and the fixed housing are provided with a flexible sealing part, so that an annular cavity is formed among the flexible sealing part, the inner magnetic conductive plate and the outer magnetic conductive plate. The annular cavity is filled with magnetorheological fluid. While the flexible sealing part plays a sealing role, it cooperates with the fixed housing to limit the connecting bearing. When the main shaft generates radial vibration, it drives the connecting bearing to vibrate, and the flexible sealing part can also play a preliminary buffering and damping role. The permanent magnet generates a basic radial magnetic field. After the exciting coils are energized, a superimposed magnetic field is generated. By adjusting the current, the viscosity of the magnetorheological fluid can be changed to perform active vibration suppression. Even the current intensity of multiple exciting coils can be adjusted separately to control the different magnetic field intensities of the magnetic fields in each part, and targeted vibration suppression can be adjusted according to the vibration.

[0017] The aforementioned water turbine system based on cavitation resistance and active vibration suppression, the sensor module is arranged on the outer side wall of the connecting bearing extending out of the fixed housing. The sensor module includes a multi-axis vibration sensor, which can adopt one or more of the x-axis, y-axis, and z-axis sensors to detect the amplitude data of the connecting bearing at different angles.

[0018] The aforementioned water turbine system based on cavitation resistance and active vibration suppression, the permanent magnet adopts a neodymium iron boron ring permanent magnet, the inner diameter of which matches the connecting bearing, and the N-S alternating magnetic poles are evenly distributed in the circumferential direction, and the magnetic pole included angle is 60°, forming a uniform radial magnetic field with a magnetic field intensity of 0.8-1.0T.

[0019] The aforementioned water turbine system based on cavitation resistance and active vibration suppression, the exciting coils are distributed double-layer windings, and the coil pitch is an integer multiple of the number of blades. During the operation of the water turbine, the blades periodically cut the water flow, which will cause hydraulic excitation vibration related to the number of blades. When the coil pitch is an integer multiple of the number of blades, the periodic change of the magnetic field distribution can be synchronized with the vibration order of the blade passing frequency, so as to accurately cancel the vibration energy of a specific order and avoid resonance amplification.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] (1) The present invention effectively improves the cavitation resistance performance. By laser cladding a cobalt-based alloy layer, a high-hard matrix is provided. The bionic trapezoidal micro-grooves stabilize the flow of the boundary layer, thereby reducing the impact of cavitation bubble collapse, and the cavitation rate during operation is significantly reduced.

[0022] (2) The vibration suppression effect of the present invention is remarkable. The permanent magnet provides a basic magnetic field, and the excitation coil realizes dynamic adjustment. By adjusting the viscosity of the magnetorheological fluid through current, the low-frequency vibration of 0.5 - 10 Hz is suppressed. Through the intelligent control unit, intelligent and dynamic adjustment is carried out according to the vibration data and the conventional operation data of the hydropower system. Through precise magnetic field control, reliable mechanical connection and intelligent dynamic adjustment, the problem of low-frequency vibration of the water turbine is solved, providing core technical support for the long-term safe operation of hydropower equipment.

[0023] (3) The present invention effectively improves the overall operation efficiency. The bionic grooves optimize the flow pattern, reduce the turbulence degree at the runner outlet, recover the kinetic energy of the tail water. At the same time, with dynamic guide vane adjustment, the guide vane opening matches the flow rate in real time, reducing hydraulic losses and improving power generation efficiency.

[0024] (4) The present invention reduces the maintenance cost. By reducing cavitation and actively suppressing vibration, the service life of the water turbine is effectively extended, the replacement frequency is reduced, and the repair and replacement costs are saved. Brief Description of the Drawings

[0025] Figure 1 is the system schematic diagram of the present invention;

[0026] Figure 2 is the structural schematic diagram of the water turbine of the present invention;

[0027] Figure 3 is the schematic diagram of the blade shape of the present invention;

[0028] Figure 4 is the partial enlarged schematic diagram of the blade of the present invention;

[0029] Figure 5 is the cross-sectional view of the blade of the present invention;

[0030] Figure 6 is the structural schematic diagram of the active vibration suppression device of the present invention;

[0031] Figure 7 is Figure 6 the cross-sectional view at position A in

[0032] Figure 8 is the control schematic diagram of the present invention.

[0033] Reference numerals: 1 - water turbine, 101 - blade, 101a - leading edge, 101b - trailing edge, 102 - housing, 103 - guide bearing, 104 - rotating shaft, 105 - guide vane, 106 - control link, 2 - main shaft, 3 - speed increaser, 4 - generator, 5 - bionic groove, 6 - active vibration suppression device, 601 - fixed housing, 602 - connecting bearing, 603 - permanent magnet, 604 - inner magnetic conductive plate, 605 - excitation coil, 606 - outer magnetic conductive plate, 607 - flexible seal part, 7 - sensor module, 8 - intelligent control unit.

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Specific embodiments

[0035] Embodiment 1 of the present invention: A water turbine system based on cavitation resistance and active vibration suppression, comprising: a water turbine 1, the water turbine 1 is connected to the upstream water source and the downstream reservoir through the inlet pipe and the outlet pipe respectively, one end of the output end of the water turbine 1 is connected to one end of the main shaft 2, and the other end of the main shaft 2 is sequentially connected to a speed increaser 3 and a generator 4. Among them, the water turbine 1 includes blades 101, a housing 102, and a guide bearing 103 arranged in the housing 102. A rotating shaft 104 is installed on the guide bearing 103. One end of the rotating shaft 104 is connected to the main shaft 2, and the other end of the rotating shaft 104 extends into the inner cavity of the housing 102 and is provided with a plurality of blades 101 distributed around. A guide vane 105 is arranged at the water inlet end of the housing 102. The guide vane 105 is connected to a control link 106, and the control link 106 is electrically connected to the intelligent control unit 8. The intelligent control unit 8 can adjust the opening of the guide vane 105 based on the real-time flow data to destroy the formation conditions of the draft tube vortex band.

[0036] An active vibration suppression device 6, the active vibration suppression device 6 is installed on the main shaft 2 and is used to actively suppress the vibration generated by the main shaft 2 when the water turbine 1 works. The active vibration suppression device 6 adopts controllable magnetic field damping to suppress low-frequency vibrations of 0.5 - 10 Hz and can be actively regulated;

[0037] A sensor module 7, the sensor module 7 is arranged on the main shaft 2 and is used to detect the vibration data of the main shaft 2;

[0038] An intelligent control unit 8, the intelligent control unit 8 is electrically connected to the water turbine 1, the sensor module 7, and the active vibration suppression device 6 respectively, and is used to control the operating parameters of the active vibration suppression device 6 and the water turbine 1 according to the vibration data obtained by the sensor module 7. The intelligent control unit 8 can adopt an industrial computer to obtain the low-frequency vibration information of the main shaft 2 collected by the sensor module 7, and perform analysis and calculation according to the original operation data of the hydropower electric control system to adjust the operating parameters of the dynamic vibration suppression device 6.

[0039] Specifically, the surface of the blade 101 is provided with a laser cladding cobalt-based alloy layer, which significantly improves surface wear resistance and chemical corrosion resistance, can effectively resist the impact of cavitation bubble collapse, and extends the service life. The pressure surface of the blade 101 is distributed with a bionic micro-groove array, which mimics the micro-groove texture of shark skin, optimizes the flow channel of the blade 101, reduces turbulent separation, and thus inhibits the generation of cavitation effect. Among them, the upper and lower sides of the blade 101 are the water inlet edge 101a and the water outlet edge 101b respectively. The bionic micro-groove array is composed of multiple bionic grooves 5 extending from the water inlet edge 101a to the water outlet edge 101b. The cross-section of the bionic groove 5 is trapezoidal. The inclined surfaces on both sides of the trapezoidal bionic groove 5 can guide the water flow into the bionic groove 5 gently, reduce the turbulent vortices generated by flow separation, and the trapezoidal cross-section forms a stable secondary eddy current at the bottom of the bionic groove 5, reducing the main flow shear stress and inhibiting the initial cavitation. The long side width of the bionic groove 5 is 80, the short side width is 50, the depth is 20, and the spacing is 200. And, the water inlet edge 101a of the blade 101 is arc-shaped and the radius of the water inlet edge 101a gradually increases from the inside to the outside. The inner end of the water inlet edge 101a gradually goes down while the outer end gradually goes up, which can guide the water flow towards the inner hub direction of the blade 101, reduce the low-pressure area on the back of the water inlet edge 101a of the blade and improve the water flow impact near the front water inlet edge 101a, which is beneficial to the improvement of cavitation performance.

[0040] Embodiment 2 of the present invention: A hydraulic turbine system based on anti-cavitation and active vibration suppression, including: a hydraulic turbine 1, the hydraulic turbine 1 is connected to the upstream water source and the downstream reservoir through an inlet pipe and an outlet pipe respectively. One end of the output end of the hydraulic turbine 1 is connected to one end of a main shaft 2, and the other end of the main shaft 2 is sequentially connected to a speed increaser 3 and a generator 4. Among them, the hydraulic turbine 1 includes blades 101, a housing 102, and a guide bearing 103 arranged in the housing 102. A rotating shaft 104 is installed on the guide bearing 103. One end of the rotating shaft 104 is connected to the main shaft 2, and the other end of the rotating shaft 104 extends into the inner cavity of the housing 102 and is provided with a plurality of blades 101 distributed in a surrounding manner. A guide vane 105 is arranged at the water inlet end of the housing 102. The guide vane 105 is connected to a control link 106, and the control link 106 is electrically connected to the intelligent regulation unit 8. The intelligent regulation unit 8 can adjust the opening of the guide vane 105 based on real-time flow data to destroy the formation conditions of the draft tube vortex band.

[0041] An active vibration suppression device 6, the active vibration suppression device 6 is installed on the main shaft 2 and is used to actively suppress the vibration generated by the main shaft 2 when the hydraulic turbine 1 works. The active vibration suppression device 6 adopts a controllable magnetic field damping to suppress low-frequency vibrations of 0.5 - 10 Hz and can be actively regulated;

[0042] A sensor module 7, the sensor module 7 is arranged on the main shaft 2 and is used to detect the vibration data of the main shaft 2;

[0043] The intelligent control unit 8 is electrically connected to the water turbine 1, the sensor module 7, and the active vibration suppression device 6 respectively, and is used to control the operating parameters of the active vibration suppression device 6 and the water turbine 1 according to the vibration data obtained by the sensor module 7. The intelligent control unit 8 can adopt an industrial computer to obtain the low-frequency vibration information of the main shaft 2 collected by the sensor module 7, and analyze and calculate according to the original operation data of the hydropower electric control system to adjust the operating parameters of the dynamic vibration suppression device 6.

[0044] Specifically, the surface of the blade 101 is provided with a laser cladding cobalt-based alloy layer, which significantly improves the surface wear resistance and chemical corrosion resistance, can effectively resist the impact of cavitation bubble collapse, and extends the service life. The pressure surface of the blade 101 is distributed with a bionic microgroove array, which imitates the microgroove texture of shark skin, optimizes the flow channel of the blade 101, reduces turbulent separation, and thus inhibits the generation of cavitation erosion effect. Among them, the upper and lower sides of the blade 101 are the water inlet edge 101a and the water outlet edge 101b respectively. The bionic microgroove array is composed of a plurality of bionic grooves 5 extending from the water inlet edge 101a to the water outlet edge 101b. The cross-section of the bionic groove 5 is trapezoidal. The inclined surfaces on both sides of the trapezoidal bionic groove 5 can guide the water flow into the bionic groove 5 gently, reduce the turbulent vortices generated by flow separation, and the trapezoidal cross-section forms a stable secondary eddy current at the bottom of the bionic groove 5, reducing the main flow shear stress and inhibiting the initial cavitation. The long side width of the bionic groove 5 is 100 μm, the short side width is 70 μm, the depth is 30 μm, and the spacing is 300 μm. And, the water inlet edge 101a of the blade 101 is arc-shaped and the radius of the water inlet edge 101a gradually increases from the inside to the outside. The inner end of the water inlet edge 101a gradually goes down while the outer end gradually goes up, which can guide the water flow towards the inner hub direction of the blade 101, reduce the low-pressure area on the back of the water inlet edge 101a of the blade and improve the water flow impact near the front water inlet edge 101a, which is beneficial to the improvement of cavitation performance.

[0045] Embodiment 3 of the present invention: A water turbine system based on anti-cavitation and active vibration suppression, including: a water turbine 1, the water turbine 1 is connected to the upstream water source and the downstream reservoir through the water inlet pipe and the water outlet pipe respectively. One end of the output end of the water turbine 1 is connected to one end of the main shaft 2, and the other end of the main shaft 2 is sequentially connected to a speed increaser 3 and a generator 4. Among them, the water turbine 1 includes blades 101, a housing 102, and a guide bearing 103 arranged in the housing 102. A rotating shaft 104 is installed on the guide bearing 103. One end of the rotating shaft 104 is connected to the main shaft 2, and the other end of the rotating shaft 104 extends into the inner cavity of the housing 102 and is provided with a plurality of blades 101 distributed in a surrounding manner. A guide vane 105 is arranged at the water inlet end of the housing 102. The guide vane 105 is connected to a control link 106, and the control link 106 is electrically connected to the intelligent control unit 8. The intelligent control unit 8 can adjust the opening of the guide vane 105 based on real-time flow data to destroy the formation conditions of the draft tube vortex band.

[0046] The active vibration suppression device 6 is installed on the main shaft 2 and is used to actively suppress the vibration generated by the main shaft 2 during the operation of the water turbine 1. The active vibration suppression device 6 adopts controllable magnetic field damping to suppress low-frequency vibrations of 0.5 - 10 Hz and can be actively regulated;

[0047] The sensor module 7 is arranged on the main shaft 2 and is used to detect the vibration data of the main shaft 2;

[0048] The intelligent control unit 8 is electrically connected to the water turbine 1, the sensor module 7, and the active vibration suppression device 6 respectively, and is used to control the operating parameters of the active vibration suppression device 6 and the water turbine 1 according to the vibration data obtained by the sensor module 7. The intelligent control unit 8 can adopt an industrial computer to obtain the low-frequency vibration information of the main shaft 2 collected by the sensor module 7 and perform analysis and calculation based on the original operation data of the hydropower electric control system to adjust the operating parameters of the dynamic vibration suppression device 6.

[0049] Specifically, the surface of the blade 101 is provided with a laser cladding cobalt-based alloy layer, which significantly improves the surface wear resistance and chemical corrosion resistance, can effectively resist the impact of cavitation bubble collapse, and prolongs the service life. The pressure surface of the blade 101 is distributed with a bionic microgroove array, which imitates the microgroove texture of shark skin, optimizes the flow channel of the blade 101, reduces turbulent separation, and thus inhibits the generation of cavitation effect. Among them, the upper and lower sides of the blade 101 are the water inlet edge 101a and the water outlet edge 101b respectively. The bionic microgroove array is composed of multiple bionic grooves 5 extending from the water inlet edge 101a to the water outlet edge 101b. The cross-section of the bionic groove 5 is trapezoidal. The inclined surfaces on both sides of the trapezoidal bionic groove 5 can guide the water flow into the bionic groove 5 gently, reduce the turbulent vortices generated by flow separation, and the trapezoidal cross-section forms a stable secondary eddy current at the bottom of the bionic groove 5, reducing the main flow shear stress and inhibiting the initial cavitation. The long side width of the bionic groove 5 is 95 μm, the short side width is 60 μm, the depth is 24 μm, and the spacing is 275 μm. And, the water inlet edge 101a of the blade 101 is arc-shaped and the radius of the water inlet edge 101a gradually increases from the inside to the outside. The inner end of the water inlet edge 101a gradually descends while the outer end gradually ascends, which can guide the water flow towards the inner hub direction of the blade 101, reduce the low-pressure area on the back of the water inlet edge 101a of the blade and improve the water flow impact near the front water inlet edge 101a, which is beneficial to the improvement of cavitation performance.

[0050] Embodiment 4 of the present invention: A water turbine system based on cavitation resistance and active vibration suppression, comprising: a water turbine 1, the water turbine 1 is connected to the upstream water source and the downstream reservoir through an inlet pipe and an outlet pipe respectively, one end of the output end of the water turbine 1 is connected to one end of a main shaft 2, and the other end of the main shaft 2 is sequentially connected to a speed increaser 3 and a generator 4. Among them, the water turbine 1 includes blades 101, a housing 102, and a guide bearing 103 arranged in the housing 102. A rotating shaft 104 is installed on the guide bearing 103. One end of the rotating shaft 104 is connected to the main shaft 2, and the other end of the rotating shaft 104 extends into the inner cavity of the housing 102 and is provided with a plurality of blades 101 distributed in a circumferential manner. A guide vane 105 is arranged at the water inlet end of the housing 102. The guide vane 105 is connected to a control link 106, and the control link 106 is electrically connected to an intelligent control unit 8. The intelligent control unit 8 can adjust the opening of the guide vane 105 based on real-time flow data to destroy the formation conditions of the draft tube vortex band. The surface of the blade 101 is provided with a laser cladding cobalt-based alloy layer, which significantly improves surface wear resistance and chemical corrosion resistance, can effectively resist the impact of cavitation bubble collapse, and prolongs the service life. The pressure surface of the blade 101 is distributed with a bionic microgroove array, which imitates the microgroove texture of shark skin, optimizes the flow channel of the blade 101, reduces turbulent separation, and thus suppresses the generation of cavitation effect. Among them, the upper and lower sides of the blade 101 are the inlet edge 101a and the outlet edge 101b respectively. The bionic microgroove array is composed of a plurality of bionic grooves 5 extending from the inlet edge 101a to the outlet edge 101b. The cross-section of the bionic groove 5 is trapezoidal. The two inclined surfaces of the trapezoidal bionic groove 5 can guide the water flow into the bionic groove 5 gently, reduce the turbulent vortices generated by flow separation, and the trapezoidal cross-section forms a stable secondary eddy current at the bottom of the bionic groove 5, reducing the main flow shear stress and suppressing the initial cavitation. The long side width of the bionic groove 5 is 95 μm, the short side width is 60 μm, the depth is 24 μm, and the spacing is 275 μm. And, the inlet edge 101a of the blade 101 is arc-shaped and the radius of the inlet edge 101a gradually increases from the inside to the outside. The inner end of the inlet edge 101a gradually goes down while the outer end gradually goes up, which can guide the water flow towards the inner hub direction of the blade 101, reduce the low-pressure area on the back of the inlet edge 101a of the blade and improve the water flow impact near the front inlet edge 101a, which is beneficial to the improvement of cavitation performance.

[0051] The active vibration suppression device 6 is installed on the main shaft 2 and is used to actively suppress the vibration generated by the main shaft 2 during the operation of the water turbine 1. The active vibration suppression device 6 uses controllable magnetic field damping to suppress low-frequency vibrations of 0.5 - 10 Hz and can be actively regulated. Among them, the active vibration suppression device 6 includes a fixed housing 601 and a connecting bearing 602 installed on the main shaft 2. The connecting bearing 602 penetrates the fixed housing 601 and has a gap with the fixed housing 601. A permanent magnet 603 is arranged around the outer side wall of the connecting bearing 602, and an inner magnetic conductive plate 604 is coated on the outer surface of the permanent magnet 603. The inner side wall of the inner cavity of the fixed housing 601 is distributed around the center line of the main shaft 2 with exciting coils 605. The exciting coils 605 are electrically connected to the intelligent regulation unit 8, and an outer magnetic conductive plate 606 is coated on the surface of the exciting coils 605. The inner magnetic conductive plate 604 and the fixed housing 601 are provided with a flexible sealing part 607, so that an annular cavity 607 is formed between the flexible sealing part 607, the inner magnetic conductive plate 604 and the outer magnetic conductive plate 606. The annular cavity 607 is filled with magnetorheological fluid. While the flexible sealing part 607 plays a sealing role, it cooperates with the fixed housing 601 to limit the connecting bearing 602. When the main shaft 2 generates radial vibration, it drives the connecting bearing 602 to vibrate, and the flexible sealing part 607 can also play a preliminary buffering and damping role. The permanent magnet 603 generates a basic radial magnetic field. After the exciting coils 605 are energized, a superimposed magnetic field is generated. By adjusting the current, the viscosity of the magnetorheological fluid can be changed to actively suppress vibration. Even the current intensities of multiple exciting coils 605 can be adjusted separately to control the different magnetic field intensities of the magnetic fields in each part and perform targeted vibration suppression adjustment according to the vibration.

[0052] Preferably, the permanent magnet 603 is a neodymium iron boron ring permanent magnet with a remanence ≥ 1.3 T, a coercivity ≥ 955 kA / m, an inner diameter matching the connecting bearing 602, preferably the outer diameter of the connecting bearing 602 is Φ300 mm, the inner diameter of the permanent magnet 603 is Φ302 mm, the outer diameter is Φ400 mm, the axial thickness is 20 mm, and 6 pairs of N - S alternating magnetic poles are evenly distributed in the circumferential direction, with a magnetic pole included angle of 60°, forming a uniform radial magnetic field with a magnetic field intensity of 0.8 - 1.0 T. The exciting coils 605 are distributed double-layer windings, with 50 turns in each layer, made of copper core enameled wire with a wire diameter of 1.5 mm, and a resistivity of 0.017 Ω·mm 2 / m. The coil pitch has an integer multiple relationship with the number of blades 101. For example, when the number of runner blades is 15, the coil pitch is 15 mm. During the operation of the water turbine 1, the blades 101 periodically cut the water flow, which will cause hydraulic excitation vibration related to the number of blades 101. When the coil pitch has an integer multiple relationship with the number of blades 101, the periodic change of the magnetic field distribution can be synchronized with the vibration order of the passing frequency of the blades 101, so as to accurately cancel the vibration energy of specific orders and avoid resonance amplification.

[0053] The sensor module 7 is arranged on the main shaft 2 and is used to detect the vibration data of the main shaft 2. The sensor module 7 is arranged on the outer side wall of the connecting bearing 602 that extends out of the fixed housing 601. The sensor module 7 includes a multi-axis vibration sensor, and one or more of 3-axis, 6-axis, and 9-axis sensors can be used to detect the amplitude data of the connecting bearing 602 at different angles.

[0054] The intelligent control unit 8 is electrically connected to the water turbine 1, the sensor module 7, and the active vibration suppression device 6 respectively, and is used to control the operating parameters of the active vibration suppression device 6 and the water turbine 1 according to the vibration data obtained by the sensor module 7. The intelligent control unit 8 can use an industrial computer to obtain the low-frequency vibration information of the main shaft 2 collected by the sensor module 7, and perform analysis and calculation based on the operating data of the original hydropower electronic control system to adjust the operating parameters of the dynamic vibration suppression device 6.

[0055] The working principle of an embodiment of the present invention: During the operation of the present invention, the water turbine 1 operates for hydropower generation. The trapezoidal micro-grooves guide the water flow to transition smoothly, reduce turbulent separation, suppress the initial cavitation, and at the same time reduce the boundary layer turbulence by 40%, and reduce the hydraulic loss by 2%-3%; optimize the guide vane opening in real time, reduce the outlet flow velocity gradient, increase the pressure in the cavitation-sensitive area, and suppress the occurrence of the cavitation effect; the sensor module 7 detects the vibration data of the main shaft 2 in real time. When the main shaft 2 generates radial vibration, it drives the connecting bearing 602 to vibrate, and the flexible sealing part 607 can also play a preliminary buffering and damping role. The permanent magnet 603 generates a basic radial magnetic field. The intelligent control unit 8 energizes the excitation coil 605 according to the acquired data to generate a superimposed magnetic field, and adjusts the current of the excitation coil 605 to change the viscosity of the magnetorheological fluid, so as to perform active vibration suppression and intelligent regulation.

[0056] Among them, the dynamic working principle of the active vibration suppression device 6 is as follows:

[0057] Static magnetic field: The permanent magnet 603 generates a basic radial magnetic field.

[0058] Dynamic superimposed magnetic field: After the excitation coil 605 is energized, an axial magnetic field is generated, and the viscosity of the magnetorheological fluid is changed by adjusting the current (0-5A). Its dynamic adjustment process is as follows:

[0059] Step 1: The sensor module 7 collects the vibration signal x(t) of the main shaft 2, and extracts the dominant frequency f (such as 1.2 Hz) through analysis;

[0060] Step 2: The intelligent control unit 8 outputs the target current I (such as I target = 3.2 A) according to the preset f-I response curve;

[0061] Step 3: Adjust the supply current of the excitation coil 605, the magnetic field of the excitation coil 605 is enhanced, and the viscosity of the magnetorheological fluid increases;

[0062] Step 4: Monitor the vibration amplitude in real time and correct the current in real time.

Claims

1. A hydroturbine system based on cavitation resistance and active vibration suppression, comprising a hydroturbine (1), wherein the hydroturbine (1) is connected to an upstream water source and a downstream reservoir through an inlet pipe and an outlet pipe respectively, one end of a main shaft (2) is connected to the output end of the hydroturbine (1), and the other end of the main shaft (2) is sequentially connected to a speed increaser (3) and a generator (4), characterized in that, Also includes: A blade (101) is arranged in a water turbine (1), wherein a bionic micro-groove array is distributed on a pressure surface of the blade (101); An active vibration suppression device (6), the active vibration suppression device (6) being installed on the main shaft (2) and being used to actively suppress vibrations generated by the main shaft (2) when the turbine (1) is operating; A sensor module (7) is provided on the main shaft (2) and is used to detect vibration data of the main shaft (2); and an intelligent control unit (8) is electrically connected to the turbine (1), the sensor module (7) and the active vibration suppression device (6) respectively, and is used to control the operating parameters of the active vibration suppression device (6) and the turbine (1) according to the vibration data acquired by the sensor module (7).

2. The hydroturbine system based on anti-cavitation and active vibration suppression according to claim 1, wherein The water turbine (1) further comprises a housing (102) and a guide bearing (103) arranged in the housing (102); a rotating shaft (104) is mounted on the guide bearing (103); one end of the rotating shaft (104) is connected to the main shaft (2); the other end of the rotating shaft (104) extends toward the inner cavity of the housing (102) and is provided with a plurality of blades (101) distributed around it; a guide vane (105) is provided at the water inlet end of the housing (102); the guide vane (105) is connected to a control link (106); and the control link (106) is electrically connected to the intelligent control unit (8).

3. A water turbine system based on cavitation resistance and active vibration suppression according to claim 1, characterized in that The upper and lower sides of the blade (101) are respectively a water inlet edge (101a) and a water outlet edge (101b); the bionic micro-groove array is composed of a plurality of bionic grooves (5) extending from the water inlet edge (101a) to the water outlet edge (101b); and the cross-section of the bionic grooves (5) is trapezoidal.

4. A water turbine system based on cavitation resistance and active vibration suppression according to claim 3, characterized in that The bionic groove (5) has a long side width of 80-100 μm, a short side width of 50-70 μm, a depth of 20-30 μm, and a spacing of 200-300 μm.

5. A hydroturbine system based on anti-cavitation and active vibration suppression according to claim 3 or 4, characterized in that, The water inlet edge (101a) of the blade (101) is arc-shaped, and the radius of the water inlet edge (101a) gradually increases from the inside to the outside, and the inner end of the water inlet edge (101a) gradually points downward while the outer end gradually points upward.

6. The water turbine system based on cavitation resistance and active vibration suppression according to claim 5, characterized in that, The surface of the blade (101) is provided with a laser-clad cobalt-based alloy layer.

7. A water turbine system based on cavitation resistance and active vibration suppression according to claim 1, characterized in that, The active vibration suppression device (6) includes a fixed housing (601) and a connecting bearing (602) mounted on the main shaft (2). The connecting bearing (602) penetrates the fixed housing (601) and has a gap with the fixed housing (601). A permanent magnet (603) is disposed around the outer sidewall of the connecting bearing (602). An inner magnetic conductive plate (604) is coated on the outer surface of the permanent magnet (603). The inner sidewall of the inner cavity of the fixed housing (601) is distributed around the center line of the main shaft (2) with exciting coils (605). The exciting coils (605) are electrically connected to the intelligent control unit (8). An outer magnetic conductive plate (606) is coated on the surface of the exciting coils (605). A flexible sealing portion (607) is provided between the inner magnetic conductive plate (604) and the fixed housing (601), so that an annular cavity (607) is formed among the flexible sealing portion (607), the inner magnetic conductive plate (604) and the outer magnetic conductive plate (606). The annular cavity (607) is filled with magnetorheological fluid.

8. A hydroturbine system based on cavitation resistance and active vibration suppression according to claim 7, characterized in that, The sensor module (7) is disposed on the outer sidewall of the connecting bearing (602) extending out of the fixed housing (601). The sensor module (7) includes a multi-axis vibration sensor.

9. A hydroturbine system based on cavitation resistance and active vibration suppression according to claim 7, characterized in that, The permanent magnet (603) is a neodymium iron boron ring permanent magnet, with an inner diameter matching that of the connecting bearing (602), and 6 pairs of N-S alternating magnetic poles are circumferentially and evenly distributed, with a magnetic pole included angle of 60°, constituting a uniform radial magnetic field with a magnetic field intensity of 0.8 - 1.0 T.

10. A water turbine system based on anti-cavitation and active vibration suppression according to claim 7, characterized in that, The exciting coil (605) is a distributed double-layer winding, and the coil pitch has an integer multiple relationship with the number of blades (101).

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