Magnetorheological fluid self-adaptive ice-resistant wind turbine blade and control method

Abstract

The invention belongs to the technical field of ice resistance of wind power generation equipment, and particularly relates to a magnetorheological fluid self-adaptive ice-resistant wind turbine blade and a control method.The wind turbine blade comprises a shell, and a girder, rib plates connected with the girder, core materials spaced from the rib plates and electromagnets connected with the rib plates are installed in the shell; wherein a cavity area is formed in the front edge area of the shell, an MRF interlayer and a skin which are attached to each other are installed in the cavity area, and a PLC used for controlling the electromagnet is installed at the root of the shell; when the electromagnet is started, the MRF interlayer is solidified through the magnetic field effect of the electromagnet so as to extrude the ice layer attached to the outer portion, otherwise, the electromagnet is dormant, the MRF interlayer is made to recover to be in the liquid state, and therefore the pneumatic form of the blade is maintained after deicing. The control method comprises steps 1-7. The transient curing characteristic of the magnetorheological fluid under the action of a magnetic field is utilized, the surface morphology of the blade is dynamically regulated and controlled, the continuity of an ice layer is destroyed, and meanwhile pneumatic smoothness is recovered in an ice-free state.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-icing of wind power generation equipment, and in particular relates to a magnetorheological fluid adaptive anti-icing wind turbine blade and a control method. Background Art

[0002] Wind turbine blades are prone to ice formation in high-humidity environments of -30℃ to 0℃, and traditional anti-icing technologies face significant challenges. For example, electric heating for deicing consumes more than 100kW per unit, and the heating elements are prone to aging and damage after long-term operation. Although the application of superhydrophobic coatings can reduce the adhesion of water droplets, their inhibitory effect on medium-thick ice (ice thickness > 1mm) is limited, and the corresponding ice layer adhesion is still above 15kPa. Mechanical vibration deicing requires an additional power source, the system is complex, and the energy utilization rate is less than 30%.

[0003] When existing blades break ice, intelligent electronically controlled machinery is mainly used to break the ice layer. However, the existing solutions have defects such as a response time interval of more than 10s, a single morphological control that can only achieve smooth-rough conversion, and high energy consumption. For example, the anti-icing structure based on shape memory alloy has a fixed phase change temperature and cannot be dynamically adjusted according to the environment. The response time is as long as 30s, which is difficult to cope with rapid icing scenarios. For example, a Chinese invention with publication number CN117090247A was retrieved, which invented an offshore wind power foundation anti-icing device and anti-icing method that can be adjusted with ocean currents. The impeller assembly used can rotate and rise around the steel pipe pile under the impact of all-directional ocean currents, driving the angle between the upper and lower ice-breaking rods to change, thereby destroying sea ice and reducing the probability of ice-induced vibration of the structure. When the ocean current weakens, the spring rebounds and presses down the movable collar to gradually return the anti-icing device to its position.

[0004] When a wind turbine is in use, an intelligent electrically controlled ice-breaking rod is added to the blade. Although it can automatically break ice, it greatly increases the surface roughness of the blade. When there is no ice, it produces obvious wind resistance, which is not conducive to restoring the aerodynamic smoothness of the blade after de-icing. Therefore, the present invention proposes a magnetorheological fluid adaptive anti-icing wind turbine blade, and a method for controlling the blade to restore aerodynamic smoothness after de-icing. Summary of the Invention

[0005] The purpose of the present invention is to provide a magnetorheological fluid adaptive anti-ice wind turbine blade and control method, which can utilize the transient solidification characteristics of magnetorheological fluid under the action of a magnetic field to dynamically regulate the surface morphology of the blade, destroy the continuity of the ice layer, and restore aerodynamic smoothness in an ice-free state.

[0006] The technical solutions adopted by the present invention are as follows: A magnetorheological fluid adaptive anti-icing wind turbine blade comprises a shell, wherein a beam, a rib connected to the beam, a core material spaced from the rib, and an electromagnet connected to the rib are installed inside the shell; The front edge of the shell is provided with a cavity area, the cavity area is installed with a mutually bonded MRF interlayer and skin, and the root of the shell is installed with a PLC controller for controlling the electromagnet; When the electromagnet is activated, the magnetic field of the electromagnet solidifies the MRF interlayer to squeeze the ice layer attached to the outside. Conversely, the electromagnet is dormant, causing the MRF interlayer to return to a liquid state, thereby maintaining the aerodynamic shape of the blade after de-icing.

[0007] As an optional solution, a humidity sensor and a temperature sensor are installed in the front edge area of ​​the shell at a position offset from the cavity area, and both the humidity sensor and the temperature sensor are connected to the PLC controller; The humidity sensor and the temperature sensor monitor the temperature and humidity signals outside the blade and send them to the PLC controller for controlling the working state of the electromagnet.

[0008] As an optional solution, a hollow alloy skeleton is installed inside the beam along the axial direction of the shell, and an insulating mounting frame for supporting the electromagnet is passed through the alloy skeleton, and a ratchet in contact with the bottom wall of the alloy skeleton is fixed at the bottom of the insulating mounting frame.

[0009] As an optional solution, a moisture-absorbing cotton strip surrounding the electromagnet and water-absorbing resin beads wrapped inside the moisture-absorbing cotton strip are provided on the top of the insulating mounting frame; When the interior of the housing is damp, the moisture-absorbing cotton strip and the water-absorbing resin beads absorb the moisture to separate the moisture from the electromagnet.

[0010] As an optional solution, a male plug and a female socket that plug into each other are further provided inside the housing, the female socket is embedded in the alloy frame, and the male plug is connected to the moisture-absorbing cotton strip; When the male plug and the female socket are plugged in, the humidity sensor and the temperature sensor are both powered on; When the moisture-absorbing tampon is damp, it is disconnected from the male plug, so that the male plug and the female socket are separated, thereby the humidity sensor and the temperature sensor are powered off and offline, indicating a fault signal.

[0011] As an optional solution, the outer side of the male plug is provided with a memory resilient piece connected to the alloy frame, the outer side of the moisture-absorbing cotton strip is provided with a water-soluble paper, and the male plug is connected to the moisture-absorbing cotton strip through the water-soluble paper; When the moisture-absorbing cotton strip is damp, the water-soluble paper dissolves in contact with water, thereby releasing the locking state of the male plug, and the male plug is separated from the female socket under the action of the elastic potential energy of the memory resilient member.

[0012] As an optional solution, an open-shaped limiting ring is inserted between the moisture-absorbing cotton strip and the water-soluble paper, the bottom of the limiting ring is fixed to the top surface of the insulating mounting frame, and a positioning node is fixed on the outside of the insulating mounting frame to engage with the opening of the limiting ring.

[0013] As an optional solution, a magnetorheological fluid adaptive anti-icing wind turbine blade control method includes the following steps: Step 1: Preparing materials: Add carbonyl iron powder, dimethyl silicone oil and fumed silica into a vacuum mixer, mix to prepare MRF, and set aside; Step 2: Blade processing: During the blade composite material forming stage, a cavity area is reserved at the leading edge of the shell, and the cavity area is filled with MRF by injection to form an MRF sandwich; Step 3: Blade forming: After the cavity area is injected, it is covered with a PET / ITO flexible conductive film. The PET / ITO flexible conductive film is bonded to the shell through a hot pressing process to form a skin. The remaining area of ​​the blade surface is then sprayed with primer and topcoat in sequence. Step 4: Arrange the magnetic field: Electromagnets are embedded along the span of the blade. The electromagnets are connected to the PLC controller at the root of the blade via shielded wires. Humidity sensors and temperature sensors are installed on the leading edge and pressure surface of the blade. Both the humidity sensor and the temperature sensor are kept at a distance from the MRF interlayer to avoid magnetic field interference. Step 5: Control and de-icing: The PLC controller is pre-written with control logic. When the temperature and humidity signals exceed the threshold, the PLC controller drives the electromagnet to apply a magnetic field to the MRF interlayer, causing it to deform and break the ice layer. When the temperature signal does not exceed the threshold, the PLC controller automatically cuts off the magnetic field, returning the MRF interlayer to a liquid state. Step 6: Testing the Blade: Install the blade specimen in a wind tunnel to simulate icing conditions. After activating the electromagnet, use a camera to record the curing process of the MRF interlayer, verify the surface changes of the MRF interlayer, and measure the changes in ice adhesion using a tensile tester. After removing the magnetic field, monitor the liquid recovery of the MRF interlayer. Step 7. Stability test: The PLC controller adopts a pulse power supply mode with a duty cycle of 1:4, and a power meter is used to monitor the average power consumption of the system and the energy consumption of continuous operation for 24 hours. 1000 magnetic field activation-off cycle tests are performed to verify the changes in the MRF solidification-liquid conversion efficiency and test the changes in the adhesion between the skin and the shell.

[0014] As an optional solution, the carbonyl iron powder, dimethyl silicone oil, and fumed silica in step 1 are stirred and mixed in a volume fraction ratio of 60%:30%:10%. The stirring is performed at a speed of 2000 rpm for 30 minutes to produce MRF. At this time, the zero-field viscosity of MRF is 1.2 Pa·s, and the shear yield strength of MRF in a 0.5 T magnetic field is greater than 50 kPa.

[0015] As an optional solution, in step 5, when the temperature signal is less than 0°C and the humidity signal is greater than 80%, the PLC controller outputs a 10kHz pulse signal to drive the electromagnet to maintain a magnetic field strength of 0.5T; When the temperature signal is ≥0°C, the PLC controller automatically cuts off the magnetic field to restore the MRF interlayer to a liquid state.

[0016] The technical effects achieved by the present invention are: The present invention provides an ice-resistant wind turbine blade with low energy consumption, fast response and adaptive adjustment. It utilizes the transient solidification characteristics of magnetorheological fluid under the action of a magnetic field to dynamically control the surface morphology of the blade, destroy the continuity of the ice layer, and restore aerodynamic smoothness in an ice-free state, thereby solving the problems of high energy consumption and slow response of traditional technologies.

[0017] The electromagnet of the present invention adopts a pulsed power supply mode with a duty cycle of 1:4 and an average power consumption of less than 5W / m², which saves 70% energy compared with continuous power supply. The magnetic field distribution is dynamically adjusted according to the icing risk area, and the magnetic field is only activated in the area 20cm to 50cm from the leading edge of the blade, reducing ineffective energy consumption.

[0018] The present invention arranges a moisture-absorbing and moisture-proof structure inside the blade, which can serve as a certain degree of protection layer for the electromagnet and disconnect when it is damp, making the temperature and humidity sensor offline and indicating a fault signal, so that maintenance personnel can check the status of the electromagnet, humidity sensor and temperature sensor in time, replace the damp electromagnet, and repair the leaking blade, which can ensure the material basis for de-icing the blade. If the possibility of moisture in the blade is ruled out, it is necessary to check the health of the entire circuit, find out the real reason for the circuit disconnection, repair it in time, and restore power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front view of a magnetorheological fluid adaptive anti-icing wind turbine blade in embodiment 1 of the present invention; Figure 2 This is a cross-sectional view of a magnetorheological fluid adaptive anti-icing wind turbine blade in Example 1 of the present invention; Figure 3 Schematic diagram of the structure of the rib plate in the first embodiment of the present invention; Figure 4 is a bottom view of the rib plate in the first embodiment of the present invention; Figure 5 This is a front view of a rib plate in a first embodiment of the present invention; Figure 6 1 is a top view of the electromagnet in combination with the humidity sensor in the first embodiment of the present invention; Figure 7 is a top view of the electromagnet in the first embodiment of the present invention; Figure 8 is a bottom view of the electromagnet in embodiment 1 of the present invention; Figure 9 is a cross-sectional view of the electromagnet in embodiment 1 of the present invention; Figure 10 This is a schematic structural diagram of the male plug and female socket in the assembled state in the first embodiment of the present invention; Figure 11 It is a flow chart of the control method in the second embodiment of the present invention.

[0020] In the accompanying drawings, the components represented by the reference numerals are as follows: 1. Shell; 2. Girder; 3. Rib; 4. Core material; 5. Skin; 6. Cavity area; 7. MRF interlayer; 8. Electromagnet; 9. PLC controller; 10. Humidity sensor; 11. Temperature sensor; 12. Alloy frame; 13. Insulation mounting frame; 14. Ratchet; 15. Moisture-absorbing cotton strip; 16. Water-absorbent resin beads; 17. Male plug; 18. Female socket; 19. Memory rebound part; 20. Water-soluble paper; 21. Limiting ring; 22. Positioning node. DETAILED DESCRIPTION

[0021] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the following examples. It should be understood that the following text is only used to describe one or more specific embodiments of the present invention and does not strictly limit the scope of protection of the present invention.

[0022] Example 1: like Figures 1-10 As shown, a magnetorheological fluid adaptive anti-icing wind turbine blade includes a shell 1, inside which are installed a beam 2, a rib plate 3 connected to the beam 2, and a core material 4 separated from the rib plate 3. The shell 1, beam 2, rib plate 3, and core material 4 are modularly prefabricated in a factory. The shell 1 can be two half shells. After the beam 2 and the rib plate 3 are assembled and fixed by bolts or welding, the core material 4, such as sponge, wood, etc., is filled, and then the two half shells are put on and seamlessly welded into a blade for installation on a wind turbine.

[0023] Refer to the attached Figure 2 、 Figure 3 and Figure 7In this embodiment, a group of electromagnets 8 are embedded in the rib 3, for example, one electromagnet 8 is arranged every 5 cm along the span of the blade. A cavity area 6 is defined in the leading edge of the shell 1, and a MRF interlayer 7 and a skin 5 are installed in the cavity 6. A PLC controller 9 for controlling the electromagnets 8 is installed at the root of the shell 1. When the electromagnets 8 are activated, the magnetic field of the electromagnets 8 solidifies the MRF interlayer 7 to squeeze out the ice layer attached to the outside. Conversely, the electromagnets 8 are dormant, causing the MRF interlayer 7 to return to a liquid state, thereby maintaining the aerodynamic shape of the blade after deicing.

[0024] Before and after the injection of the MRF interlayer 7, a skin 5 is made of PET / ITO, which is cut into pieces of specified size and laid on the upper and lower surfaces of the MRF interlayer 7 in sequence to cover the 0.1 mm thick flexible conductive film, which has both electrode and protective layer functions.

[0025] As an optional embodiment, the MRF interlayer 7 is mainly made of carbonyl iron powder, silicone oil and thickener. It can be attracted by the electromagnet 8 whose core material is the soft magnetic alloy Fe73.5Cu1Nb3Si13.5B9 after being energized, causing a sharp change in its surface roughness. It can be solidified within 20ms to form a micron-level serrated rough surface with a roughness of Ra = 5μm~10μm. The continuity of the ice layer is destroyed by the change in surface morphology. The solidified serrated structure can significantly reduce the adhesion of the ice layer, making the ice layer easier to break and fall off under the action of wind, while inhibiting the uniform spreading of water droplets on the surface and reducing the thickness of ice.

[0026] Refer to the attached Figure 1 、 Figure 2 and Figure 3 In order to finely control the micron-level serrated rough surface, in this embodiment, a humidity sensor 10 and a temperature sensor 11 are installed by screws in the front edge area of ​​the shell 1, staggered at the position of the cavity area 6, and sealant is applied to the edges. The humidity sensor 10 and the temperature sensor 11 monitor the temperature and humidity signals outside the blade. Since the humidity sensor 10 and the temperature sensor 11 are both connected to the PLC controller 9, the temperature and humidity signals can be sent to the PLC controller 9 for controlling the working state of the electromagnet 8.

[0027] For example, when the dew point temperature is less than 0°C and the humidity is greater than 80%, the PLC controller 9 outputs a 10kHz pulse signal with a duty cycle of 1:4 to drive the electromagnet 8 to maintain a magnetic field strength of 0.5T; when the dew point temperature is ≥0°C, the magnetic field is automatically cut off to restore the MRF interlayer 7 to a liquid state.

[0028] Refer to the attached Figure 4 、 Figure 7 and Figure 8In order to maintain the stability of the electromagnet 8 when the blades rotate, in this embodiment, a hollow alloy frame 12 is installed inside the beam 2 along the axial direction of the shell 1 by bolts, and an insulating mounting frame 13 for carrying the electromagnet 8 is pre-pierced through the alloy frame 12 in the factory. The insulating mounting frame 13 is glued to the alloy frame 12 with glue, and a pawl 14 in contact with the bottom wall of the alloy frame 12 is welded at the bottom of the insulating mounting frame 13. When the insulating mounting frame 13 bites the electromagnet 8, the pawl 14 is fixed to the bottom wall of the alloy frame 12 by screws, thereby holding the electromagnet 8 firmly and preventing it from shaking.

[0029] Refer to the attached Figure 6 、 Figure 7 and Figure 9 The blades are exposed to the sun and directly face the erosion of rain, which may cause slight cracks and leakage. To prevent moisture, in this embodiment, a moisture-absorbing cotton strip 15 that can surround the electromagnet 8 and water-absorbing resin beads 16 wrapped inside the moisture-absorbing cotton strip 15 are bonded to the top of the insulating mounting frame 13; when the inside of the shell 1 is damp, the moisture-absorbing cotton strip 15 and the water-absorbing resin beads 16 absorb moisture to separate the moisture and the electromagnet 8, effectively preventing the electromagnet 8 from contacting moisture and rusting due to oxidation.

[0030] Refer to the attached Figure 5 、 Figure 6 and Figure 10 Although the power supply of the electromagnet 8, the humidity sensor 10 and the temperature sensor 11 are all controlled and supervised by the PLC controller 9, in order to ensure the independent power supply of the humidity sensor 10 and the temperature sensor 11 and prevent interference from the electromagnet 8, a male plug 17 and a female socket 18 that plug into each other are further provided inside the housing 1. The female socket 18 is embedded in the alloy frame 12. The two female sockets 18 are electrically connected to the PLC controller 9, and the male plug 17 is connected to the moisture-absorbing cotton strip 15. The two male plugs 17 are electrically connected to the humidity sensor 10 and the temperature sensor 11 respectively; when the male plug 17 and the female socket 18 are plugged in, the humidity sensor 10 and the temperature sensor 11 are both energized; When the moisture-absorbing cotton strip 15 becomes damp, it is disconnected from the male plug 17, separating the male plug 17 and the female socket 18, thereby powering off the humidity sensor 10 and the temperature sensor 11 and indicating a fault signal, so that maintenance personnel can check the status of the electromagnet 8, the humidity sensor 10 and the temperature sensor 11 in time, replace the damp electromagnet 8, and repair the leaking blade, thereby ensuring the material basis for de-icing the blade.

[0031] Refer to the attached Figure 5 、 Figure 6 and Figure 10In order to ensure that the circuit is disconnected in time when it is damp, this embodiment provides a memory resilient piece 19 connected to the alloy frame 12 on the outside of the male plug 17. The memory resilient piece 19 made of memory alloy is pre-bent to a certain degree. One end of the memory resilient piece 19 is firmly glued to the outside of the male plug 17, and the other end is fastened to the alloy frame 12 by a screw. At the same time, a water-soluble paper 20 is provided on the outside of the moisture-absorbing cotton strip 15, and the male plug 17 is connected to the moisture-absorbing cotton strip 15 through the water-soluble paper 20. In this way, when the moisture-absorbing cotton strip 15 is damp, the water-soluble paper 20 dissolves in water and no longer constrains the memory resilient piece 19. The memory resilient piece 19 is quickly straightened, so that the male plug 17 is unlocked. Under the action of the elastic potential energy of the memory resilient piece 19, the male plug 17 is separated from the female socket 18 and passively triggered, thereby realizing the rapid disconnection of the circuit of the humidity sensor 10 and the temperature sensor 11.

[0032] Of course, it should be noted that the circuit disconnection of the humidity sensor 10 and the temperature sensor 11 may also be caused by cable damage, power failure, etc. During the inspection, if the possibility of moisture in the blades is ruled out, it is necessary to check the health of the entire circuit, find out the real reason for the circuit disconnection, repair it in time, and restore power supply.

[0033] Refer to the attached Figure 6 、 Figure 7 and Figure 8 The water-soluble paper 20 is made of light and thin material. In order to prevent excessive pulling between the water-soluble paper 20 and the male plug 17 when installing, an open-shaped limiting ring 21 is inserted between the moisture-absorbing cotton strip 15 and the water-soluble paper 20 to position the water-soluble paper 20. The bottom of the limiting ring 21 is bonded to the top surface of the insulating mounting frame 13. After being firmly bonded to the water-soluble paper 20, it can be tightened. A positioning node 22 is welded on the outside of the insulating mounting frame 13 and is plugged into the opening of the limiting ring 21. This allows the two ends of the water-soluble paper 20 to quickly find their position and fall into place quickly, reducing the time spent on positioning.

[0034] Example 2: like Figure 11 As shown, a method for controlling magnetorheological fluid adaptive anti-icing wind turbine blades, taking the magnetorheological fluid adaptive anti-icing wind turbine blades in Example 1 as an example, includes the following steps: Step 1: Prepare the material: Add 60% by volume of carbonyl iron powder (5 μm particle size), 30% dimethyl silicone oil (viscosity 100 cSt), and 10% fumed silica to a vacuum mixer and mix at 2000 rpm for 30 minutes to produce an MRF with a zero-field viscosity of 1.2 Pa·s and a shear yield strength of >50 kPa at a 0.5 T magnetic field. Step 2: Blade processing: During the blade composite material molding stage, a 2 mm cavity area 6 is reserved at the leading edge of the shell 1 at 0% to 30% of the chord length for integrating an MRF (magnetorheological fluid) interlayer 7. The cavity area 6 is filled with MRF by injection to form the MRF interlayer 7. Step 3: Blade forming: After the MRF prepared in step 1 is injected into the reserved cavity area 6, it is covered with a 0.1mm thick PET / ITO flexible conductive film. Through a hot pressing process, it is bonded to the shell 1 under the conditions of a set temperature of 80°C and a set pressure of 0.5MPa to form a skin 5. Then, the remaining area of ​​the blade surface is sprayed with primer and topcoat in sequence to ensure that the MRF interlayer 7 and the skin 5 have a bonding accuracy of less than 0.1mm. Among them, the primer can be made of UV light curing paint, and the topcoat can be made of epoxy resin and polyurethane paint; Step 4: Arrange the magnetic field: A group of electromagnets 8 with dimensions of 5mm×5mm×2mm are embedded every 5cm along the span of the blade. The iron core is made of the soft magnetic alloy Fe73.5Cu1Nb3Si13.5B9. The coverage area of ​​the magnetic fields of adjacent electromagnets overlaps by more than 20% to ensure uniformity. The electromagnets 8 are connected to the PLC controller 9 located at the root of the blade via shielded wires. A polymer capacitive humidity sensor 10 (accuracy of ±2%RH) and a PT100 temperature sensor 11 (accuracy of ±0.5°C) are installed on the leading edge and pressure surface of the blade. The sensor probe is kept 10mm away from the MRF interlayer 7 to avoid magnetic field interference. Step 5: Connect the two sensor signals to the PLC controller 9 located at the root of the blade. The electromagnet 8 drive circuit integrates a pulse width modulation (PWM) module, which supports 0T to 0.8T magnetic field intensity adjustment. The control logic is written as follows: when the dew point temperature is less than 0°C and the humidity is greater than 80%, the PLC controller 9 outputs a 10kHz pulse signal (duty cycle 1:4) to drive the electromagnet 8 to maintain a magnetic field intensity of 0.5T; when the dew point temperature is greater than or equal to 0°C, the magnetic field is automatically cut off, allowing the MRF interlayer 7 to return to a liquid state. Step 6: The blade specimen was installed in a -10°C low-temperature wind tunnel, with a controlled wind speed of 10 m / s and a humidity of 90% to simulate icing conditions. After activating the electromagnet, a high-speed camera with a frame rate of 1000 fps was used to record the MRF curing process, verifying that a jagged surface with a roughness of Ra = 5 μm to 10 μm was formed within 20 ms. After removing the magnetic field, the liquid recovery of the MRF interlayer 7 was monitored within 50 ms. When the magnetic field was not activated and the spraying was continued for 30 minutes, the blade ice thickness could reach 2.5 mm. After activating the magnetic field, the ice layer was fragmented, with a maximum thickness of less than 0.5 mm. The ice adhesion measured by a tensile tester dropped from 18 kPa to below 3 kPa. Step 7: Using a pulse power supply mode with a duty cycle of 1:4, a power meter was used to measure the system's average power consumption, which was 4.8W / m². The system consumed 0.12kW·h of energy during 24 hours of continuous operation. 1000 magnetic field activation-off cycles were performed to verify that the MRF solidification-liquid conversion efficiency showed no significant degradation. The adhesion between the conductive film on the blade surface and the substrate was tested to >5MPa, ensuring long-term operational stability.

[0035] In summary, the magnetorheological fluid prepared by carbonyl iron powder and silicone oil-based carrier liquid is transiently solidified within 20ms under a 0.5T magnetic field to form a serrated rough surface with a roughness of Ra = 5μm ~ 10μm, which reduces the ice adhesion from 18kPa of traditional coating to below 3kPa. Under the working conditions of -10℃ and 90% humidity, the ice thickness of the blade is suppressed from 2.5mm to below 0.5mm, effectively destroying the continuity of the ice layer. At the same time, the PLC controller 9 adopts a pulse power supply mode with a duty cycle of 1:4, and the average power consumption is only 4 0.8W / m², saving 72% energy compared to traditional electric heating, and consuming only 0.12kW·h of energy for 24-hour continuous operation. A dual-parameter trigger mechanism, temperature and humidity signal thresholds, avoids ineffective energy consumption, reducing energy consumption by a further 70% compared to traditional fixed threshold control. An array of eight micro-electromagnets achieves a magnetic field uniformity deviation of less than 5%, ensuring consistent MRF curing morphology. 1000 cycle tests verify its rheological stability with no attenuation, and the adhesion between the conductive film and the blade shell 1 exceeds 5MPa, meeting long-term fatigue resistance requirements.

[0036] In addition, the response time of PLC controller 9 is less than 20ms, and it can respond to rapid icing scenarios in real time. In the ice-free state, the MRF returns to liquid state, making the blade surface roughness Ra less than 1μm, maintaining aerodynamic efficiency, and can work stably in the temperature range of -30℃ to 0℃ and the humidity environment of 60% to 100%. It can reduce the icing downtime of wind turbines by more than 60% when operating in extremely cold and humid areas. The annual operation and maintenance cost of a single unit can be saved by more than 200,000 yuan, significantly improving the reliability of power supply of the power grid and the economy of the wind power system.

[0037] The foregoing merely represents optional embodiments of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained herein shall, unless otherwise specified or limited, be implemented in accordance with conventional means in the art.

Claims

1. A magnetorheological fluid adaptive anti-icing wind turbine blade, comprising a housing (1), characterized in that: The housing (1) is internally provided with a beam (2), a rib plate (3) connected to the beam (2), a core material (4) spaced apart from the rib plate (3), and an electromagnet (8) connected to the rib plate (3); The front edge region of the shell (1) is provided with a cavity region (6), the cavity region (6) is provided with an MRF interlayer (7) and a skin (5) that are bonded to each other, and the root of the shell (1) is provided with a PLC controller (9) for controlling the electromagnet (8); When the electromagnet (8) is activated, the MRF interlayer (7) is solidified by the magnetic field of the electromagnet (8) to squeeze the externally attached ice layer. Conversely, the electromagnet (8) is dormant, so that the MRF interlayer (7) returns to a liquid state, thereby maintaining the aerodynamic shape of the blade after de-icing.

2. The magnetorheological fluid adaptive anti-icing wind turbine blade according to claim 1, characterized in that: A humidity sensor (10) and a temperature sensor (11) are installed in the front edge area of ​​the housing (1) at a position offset from the cavity area (6), and both the humidity sensor (10) and the temperature sensor (11) are connected to the PLC controller (9); The humidity sensor (10) and the temperature sensor (11) monitor the temperature and humidity signals outside the blade and send them to the PLC controller (9) for controlling the working state of the electromagnet (8).

3. The magnetorheological fluid adaptive ice-resistant wind turbine blade according to claim 2, characterized in that: A hollow alloy frame (12) is installed inside the beam (2) along the axial direction of the shell (1), and an insulating mounting frame (13) for carrying the electromagnet (8) passes through the alloy frame (12), and a ratchet (14) in contact with the bottom wall of the alloy frame (12) is fixed at the bottom of the insulating mounting frame (13).

4. The magnetorheological fluid adaptive anti-icing wind turbine blade according to claim 3, characterized in that: The top of the insulating mounting frame (13) is provided with a moisture-absorbing cotton strip (15) surrounding the electromagnet (8) and a water-absorbing resin bead (16) wrapped inside the moisture-absorbing cotton strip (15); When the interior of the housing (1) is damp, the moisture-absorbing cotton strip (15) and the water-absorbing resin beads (16) absorb the moisture to separate the moisture from the electromagnet (8).

5. The magnetorheological fluid adaptive anti-icing wind turbine blade according to claim 4, characterized in that: A male plug (17) and a female socket (18) that plug into each other are further provided inside the housing (1), the female socket (18) being embedded in the alloy frame (12), and the male plug (17) being connected to the moisture-absorbing cotton strip (15); When the male plug (17) and the female socket (18) are plugged in, the humidity sensor (10) and the temperature sensor (11) are both energized; When the moisture-absorbing cotton strip (15) is damp, it is disconnected from the male plug (17), causing the male plug (17) and the female socket (18) to separate, thereby disconnecting the humidity sensor (10) and the temperature sensor (11), thereby disconnecting the power supply and indicating a fault signal.

6. The magnetorheological fluid adaptive anti-icing wind turbine blade according to claim 5, characterized in that: The outer side of the male plug (17) is provided with a memory resilient member (19) connected to the alloy frame (12); the outer side of the moisture-absorbing cotton strip (15) is provided with a water-soluble paper (20); the male plug (17) is connected to the moisture-absorbing cotton strip (15) via the water-soluble paper (20); When the moisture-absorbing cotton strip (15) is damp, the water-soluble paper (20) dissolves upon contact with water, thereby releasing the locking state of the male plug (17), and the male plug (17) is separated from the female socket (18) under the action of the elastic potential energy of the memory rebound member (19).

7. The magnetorheological fluid adaptive anti-icing wind turbine blade according to claim 6, characterized in that: An open-shaped limiting ring (21) is inserted between the moisture-absorbing cotton strip (15) and the water-soluble paper (20), the bottom of the limiting ring (21) is fixed to the top surface of the insulating mounting frame (13), and a positioning node (22) is fixed on the outside of the insulating mounting frame (13) and is inserted into the opening of the limiting ring (21).

8. A method for controlling a magnetorheological fluid adaptive ice-resistant wind turbine blade, applied to a magnetorheological fluid adaptive ice-resistant wind turbine blade according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Preparing materials: Add carbonyl iron powder, dimethyl silicone oil and fumed silica into a vacuum mixer, mix to prepare MRF, and set aside; Step 2: Processing the blade: During the blade composite material forming stage, a cavity area (6) is reserved in the leading edge area of ​​the shell (1), and the cavity area (6) is filled with MRF by injection to form an MRF sandwich (7); Step 3: Blade forming: After the cavity area (6) is injected, it is covered with a PET / ITO flexible conductive film, and the PET / ITO flexible conductive film is bonded to the shell (1) through a hot pressing process to form a skin (5), and then the remaining area of ​​the blade surface is sprayed with a primer and a topcoat in sequence; Step 4: Arrange the magnetic field: embed the electromagnet (8) along the span direction of the blade, connect the electromagnet (8) to the PLC controller (9) located at the root of the blade through a shielded wire, install a humidity sensor (10) and a temperature sensor (11) on the leading edge and pressure surface of the blade, and keep the humidity sensor (10) and the temperature sensor (11) at a distance from the MRF interlayer (7) to avoid magnetic field interference; Step 5: Controlling de-icing: The PLC controller (9) is pre-written with control logic. When the temperature signal and the humidity signal exceed a threshold value, the PLC controller (9) drives the electromagnet (8) to apply a magnetic field to the MRF interlayer (7), causing the MRF interlayer (7) to deform and break the ice layer. When the temperature signal does not exceed the threshold value, the PLC controller (9) automatically cuts off the magnetic field, causing the MRF interlayer (7) to return to a liquid state. Step 6: Testing the blade: Install the blade specimen in a wind tunnel to simulate icing conditions. After starting the electromagnet (8), use a camera to record the curing process of the MRF interlayer (7), verify the surface changes of the MRF interlayer (7), and measure the changes in ice adhesion using a tensile tester; after removing the magnetic field, monitor the liquid recovery of the MRF interlayer (7); Step 7, stability test: The PLC controller (9) adopts a pulse power supply mode with a duty cycle of 1:4, uses a power meter to monitor the average power consumption of the system and the energy consumption of continuous operation for 24 hours, and performs 1000 magnetic field activation-off cycle tests to verify the change of MRF solidification-liquid conversion efficiency, and at the same time test the change of adhesion between the skin (5) and the shell (1).

9. The magnetorheological fluid adaptive anti-icing wind turbine blade control method according to claim 8, characterized in that: The carbonyl iron powder, dimethyl silicone oil, and fumed silica in step 1 were stirred and mixed in a volume fraction ratio of 60%:30%:10%. The stirring was performed at a speed of 2000 rpm for 30 minutes to produce an MRF. At this time, the zero-field viscosity of the MRF was 1.2 Pa·s, and the shear yield strength of the MRF under a 0.5 T magnetic field was greater than 50 kPa.

10. The magnetorheological fluid adaptive anti-icing wind turbine blade control method according to claim 8, characterized in that: When the temperature signal is less than 0°C and the humidity signal is greater than 80% in step 5, the PLC controller (9) outputs a 10kHz pulse signal to drive the electromagnet (8) to maintain a magnetic field strength of 0.5T; When the temperature signal is ≥0°C, the PLC controller (9) automatically cuts off the magnetic field, allowing the MRF interlayer (7) to return to a liquid state.

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