Electric heating composite film for deicing and lightning protection of wind power blade and wind power blade

Abstract

The invention provides an electric heating composite film for deicing and lightning protection of a wind power blade and the wind power blade. The electric heating composite film for deicing and lightning protection of the wind power blade comprises an electric heating functional layer, an electrode on one side of the electric heating functional layer, a high-insulativity substrate on the other side of the electric heating functional layer, and an array type metal flow deflector on one side of the high-insulativity substrate. The lightning arrester is arranged on the outer surface of the wind power blade, the grounding lead is electrically connected with one end of the lightning arrester, the composite film used for deicing and lightning protection of the wind power blade is arranged at the front end of the wind power blade, and the electrode lead is electrically connected with one end of the composite film used for deicing and lightning protection of the wind power blade. According to the technical scheme, the electric heating deicing and lightning protection functions can be achieved at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine blades, and in particular to an electric heating composite film for deicing and lightning protection of wind turbine blades and a wind turbine blade. Background Art

[0002] Wind turbine blades are key components of wind turbines. They are usually made of epoxy resin-based composite materials. They are also the main moving parts of the unit that bear the most complex loads and are subject to long-term erosion by wind, sand, and rain. Since wind turbines are mostly built in areas with abundant wind energy resources, including a large number of high mountains, grasslands, Gobi deserts, coastal tidal flats and other regional landforms, wind turbines, especially blades, face severe challenges of ice accumulation and ice cover when operating in low temperature environments in winter and spring. Ice on wind turbine blades will reduce airfoil lift, increase drag, and cause blade torque to decrease, affecting the power generation efficiency of wind turbines. At the same time, due to the increase in ice coverage, the mass distribution of blades is unbalanced, resulting in asymmetric loads, which in turn causes a decrease in wind turbine output, causing mechanical failures or even shutdowns. Furthermore, during the operation of the blades, when the adhesion of the ice layer decreases, it is very easy for ice cubes to fall off. Under the action of gravity and centrifugal force, the broken ice will be thrown far away, causing damage to personnel and equipment around the unit. Therefore, the anti-freezing problem of wind turbine blades is of great practical significance for the safe and effective operation of wind turbines.

[0003] The electrothermal composite film is a two-dimensional electric heating device based on the Joule heating effect. It has the characteristics of soft texture, strong designability, uniform heating, strong weather resistance, etc. It is easy to spread and construct on the surface of the blade and shows good compatibility with epoxy resin. However, due to the electronic properties of the electrothermal composite film itself, the blades are greatly increased in probability of being struck by lightning when experiencing severe weather such as thunderstorms. In the worst case, the electrothermal composite film will be damaged and fail, and in the worst case, the wind turbine blades will crack and cause permanent damage. Therefore, designing an electrothermal composite film with lightning protection function is of great practical significance in the application of wind turbine blades. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide an electrothermal composite film and a wind turbine blade for deicing and lightning protection of wind turbine blades, which can have the two functions of high-efficiency electric heating deicing and lightning protection, so that the wind turbine blades can still work in extreme environments of high altitude, severe cold, high humidity and even thunderstorm weather.

[0005] To achieve the above-mentioned objectives, the present invention proposes an electrothermal composite film for de-icing and lightning protection of wind turbine blades. The electrothermal composite film for de-icing and lightning protection of wind turbine blades comprises: an electrothermal functional layer, an electrode on one side of the electrothermal functional layer, a high-insulation substrate on the other side of the electrothermal functional layer, and an array of metal guide plates on one side of the high-insulation substrate.

[0006] As a preferred solution, the electrode material is one or more of copper, aluminum, nickel, stainless steel, and silver.

[0007] As a preferred solution, the electrothermal functional layer is one or more of woven carbon fibers and polymer-based electrothermal composite materials.

[0008] As a preferred solution, the polymer-based electrothermal composite material consists of a polymer matrix and a conductive filler.

[0009] As a preferred embodiment, the polymer matrix includes one or more of polyimide (PI), polysulfone (PSF), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyethersulfone (PES), polydimethylsiloxane (PDMS), polyurethane (PU), and epoxy resin (EP).

[0010] As a preferred embodiment, the conductive filler includes one or more of graphite, carbon fiber, silver nanowire, conductive carbon black, copper powder, aluminum powder, iron powder, nickel powder, silver powder, silver-coated copper powder, multi-walled carbon nanotubes, single-walled carbon nanotubes, graphene and pyrolytic carbon black.

[0011] As a preferred solution, the high-insulation base material is one or more of polyurethane rubber and fluororubber.

[0012] As a preferred solution, the array-type metal guide plate is made of one or more of stainless steel, aluminum alloy, and titanium alloy.

[0013] The present invention also provides a wind turbine blade, comprising the electrothermal composite film for deicing and lightning protection of wind turbine blades described in any one of the above schemes.

[0014] As a preferred embodiment, the wind turbine blade includes: a wind turbine blade, a lightning rod on the outer surface of the wind turbine blade, a grounding lead electrically connected to one end of the lightning rod, an electrothermal composite film for deicing and lightning protection of the wind turbine blade at the front end of the wind turbine blade, and an electrode lead electrically connected to one end of the electrothermal composite film for deicing and lightning protection of the wind turbine blade.

[0015] As a preferred solution, the upper end of the lightning receptor is bonded to the electric heating composite film for deicing and lightning protection of wind turbine blades close to the edge, and a gap of less than 1 mm is retained, and the lower end of the lightning receptor is electrically connected to the grounding lead.

[0016] As a preferred solution, the electrothermal composite film for deicing and lightning protection of wind turbine blades is adhered to the outer surface of the wind turbine blade by using insulating glue, wherein the electrothermal functional layer and the electrodes face the outer surface of the wind turbine blade.

[0017] As a preferred solution, the electrodes of the electrothermal composite film used for deicing and lightning protection of wind turbine blades are electrically connected to electrode leads.

[0018] The technical solution of the present invention has the following advantages: (1) The electrothermal composite film used for wind turbine blade deicing and lightning protection has the characteristics of planar heating, uniform heating, and fast thermal response. The temperature can be quickly raised to the operating temperature range within a few minutes. At the same time, the electrothermal conversion efficiency is high, the energy consumption is low, and the heat can be quickly absorbed by the ice layer until the ice bonding interface melts and causes the ice layer to fall off.

[0019] (2) An array of metal guide plates is distributed on one side of the electrothermal composite film used for deicing and lightning protection of wind turbine blades. There are gaps between the metal guide plates, so that the side with the array of metal guide plates is in an overall insulation state. When lightning strikes, the two ends of adjacent metal segments begin to gather heterogeneous charges. When the voltage reaches a certain value, the energy released is sufficient to ionize the entire gap space. The upward leader generated by ionization preferentially merges with the downward leader of lightning. After the lightning is successfully connected, a plasma channel is formed above the array of metal guide plates. The lightning current can flow through this channel instead of being transmitted to the lightning receptor, and then be transmitted to the earth through the grounding lead. Therefore, since the lightning current is transmitted from the plasma channel above the array of metal guide plates and does not pass through the electrothermal composite film itself, it will not cause damage to the electrothermal composite film itself, and it can also protect the wind turbine blades from damage by lightning.

[0020] (3) The electrothermal composite film for wind turbine blade deicing and lightning protection of the present invention has both electric heating deicing and lightning protection functions, has high device integration, light weight, good integration with wind turbine blades, easy construction, and is suitable for large-scale application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the cross-sectional structure of the electrothermal composite membrane used for deicing and lightning protection of wind turbine blades according to the present invention; Figure 2 This is a schematic structural diagram of one side of a high-insulation substrate with an array of metal guide plates laid on a composite electrothermal film for wind turbine blade deicing and lightning protection in Example 1; Figure 3 This is a schematic structural diagram of one side of a high-insulation substrate with an array of metal guide plates laid on a composite electrothermal film for wind turbine blade deicing and lightning protection in Example 2; Figure 4 The structure diagram of the application of a composite film for wind turbine blade deicing and lightning protection on a wind turbine blade in Example 1 is shown in FIG. Figure 1 ; Figure 5 The structure diagram of the application of a composite film for wind turbine blade deicing and lightning protection on a wind turbine blade in Example 1 is shown in FIG. Figure 2 ; Explanation of the reference numerals: 1 is an electrothermal functional layer, 2 is a high-insulation substrate, 3 is an array-type metal guide plate, 4 is an electrode, 11 is an electrothermal composite film, 22 is a wind turbine blade, 33 is an electrothermal composite film without an array-type metal guide plate, 44 is a lightning arrester, 55 is a grounding lead, and 66 is an electrode lead. DETAILED DESCRIPTION

[0022] like Figures 1 to 3 As shown, the first object of the present invention is to provide an electrothermal composite film 11 for deicing and lightning protection of wind turbine blades, comprising: an electrothermal functional layer 1, an electrode 4 on one side of the electrothermal functional layer, a high-insulation substrate 2 on the other side of the electrothermal functional layer 1, and an array of metal guide plates 3 on one side of the high-insulation substrate 2.

[0023] In the above scheme, in the electric heating composite film used for deicing and lightning protection of wind turbine blades, the core of the electric heating composite film is the electric heating functional layer, which is usually made of conductive materials and can generate heat when powered on. An electrode is provided on one side of the electric heating functional layer for connecting to a power source to achieve electrical heating of the electric heating functional layer. On the other side of the electric heating functional layer is a high-insulation substrate, which plays a role of protection and isolation, ensuring that the electric heating functional layer does not contact conductive materials in the external environment during operation, thereby avoiding short circuits or leakage. An array of metal guide plates is provided on one side of the high-insulation substrate. These guide plates can evenly distribute current, ensuring that the electric heating functional layer can be evenly heated to avoid local overheating or insufficient temperature.

[0024] The above solution can improve the deicing effect. By heating the electrothermal functional layer, the ice and snow on the wind turbine blades can be quickly melted to ensure the normal operation of the blades and improve the power generation efficiency of wind turbine equipment. Improve lightning protection effect: The metal guide plate and high insulation substrate in the electrothermal composite film can provide certain lightning protection and reduce the risk of lightning damage to wind turbine blades. The electrothermal composite film is compact in design, easy to install and maintain, and will not increase the weight and complexity of wind turbine blades.

[0025] As a preferred solution, the electrode material is one or more of copper, aluminum, nickel, stainless steel, and silver; these metals have good electrical conductivity and mechanical strength, and can maintain stable electrical connections in various environments. Copper and silver have particularly good electrical conductivity, but are relatively expensive; aluminum and nickel are relatively cheap, but have slightly inferior electrical conductivity; stainless steel provides good corrosion resistance and mechanical strength. Selecting one or more of these metals as electrode materials can ensure that the electrothermal composite membrane can efficiently transmit current when powered on, while withstanding certain mechanical stresses and environmental changes.

[0026] As a preferred embodiment, the electrothermal functional layer is one or more of woven carbon fiber and polymer-based electrothermal composite material. Woven carbon fiber has excellent thermal conductivity and mechanical strength, can transfer heat evenly and quickly, and withstand large mechanical stress. Polymer-based electrothermal composite materials combine the flexibility of polymers and the electrical conductivity of conductive fillers, and can achieve electrothermal functions while maintaining flexibility. Selecting one or more of these materials as the electrothermal functional layer can ensure that the electrothermal composite film can be quickly and evenly heated when powered on, while maintaining a certain flexibility and mechanical strength.

[0027] As a preferred solution, the polymer-based electrothermal composite material is composed of a polymer matrix and a conductive filler. The polymer matrix provides the material with flexibility and mechanical strength, while the conductive filler is responsible for transmitting current and generating heat. By adjusting the ratio and type of the polymer matrix and the conductive filler, the electrothermal and mechanical properties of the electrothermal composite material can be optimized to meet different application requirements.

[0028] As a preferred solution, the polymer matrix includes one or more of polyimide (PI), polysulfone (PSF), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyethersulfone (PES), polydimethylsiloxane (PDMS), polyurethane (PU), and epoxy resin (EP). These polymer matrices have different thermal stability, mechanical strength, and chemical inertness, and can meet the application requirements in different environments. For example, PI and PEEK have excellent high-temperature stability and mechanical strength, and are suitable for applications in high-temperature environments; while PDMS and PU have good flexibility and biocompatibility, and are suitable for applications that require flexibility and biocompatibility.

[0029] As a preferred embodiment, the conductive filler includes one or more of graphite, carbon fiber, silver nanowire, conductive carbon black, copper powder, aluminum powder, iron powder, nickel powder, silver powder, silver-coated copper powder, multi-walled carbon nanotube, single-walled carbon nanotube, graphene and pyrolytic carbon black, and these conductive fillers have different conductive properties and shapes, which can affect the electrothermal and mechanical properties of the electrothermal composite material. For example, graphite and carbon fiber have high conductive properties and mechanical strength, and are suitable for applications requiring high conductivity and mechanical strength; while silver nanowire and graphene have excellent conductive properties and small size effect, and are suitable for applications requiring high conductivity and fine structure.

[0030] As a preferred solution, the high-insulation substrate material is one or more of polyurethane rubber and fluororubber. These rubber materials have excellent insulation properties and chemical corrosion resistance, and can maintain stable electrical properties in various environments. Selecting these materials as the high-insulation substrate can ensure that the electric heating composite film will not contact the conductive material in the external environment when powered on, thereby avoiding the risk of short circuit or leakage.

[0031] As a preferred solution, the array-type metal guide plate is made of one or more of stainless steel, aluminum alloy, and titanium alloy. These metal materials have good electrical conductivity and mechanical strength, and can maintain stable electrical connection and mechanical properties in various environments. Selecting these materials as the array-type metal guide plate can ensure that the current in the electrothermal composite membrane can be evenly distributed while withstanding certain mechanical stress and environmental changes. In addition, these metal materials also have certain corrosion resistance, which can extend the service life of the electrothermal composite membrane.

[0032] The specific preparation process of the above-mentioned electric heating composite film 11 for deicing and lightning protection of wind turbine blades includes the following steps: By weight, 40-60 parts of conductive filler are weighed and added to 60-40 parts of epoxy resin, and stirred at 1000-1200 rpm for 1-3 hours to make it evenly mixed, and then added to 10 parts of solvent and continued to stir for 1 hour. After mixing evenly, it is coated on one side of the high-insulation substrate without array-type metal guide plate by screen printing or scraping, and then cured at 80-120° C. for 2-12 hours to obtain an electrothermal functional layer, and then conductive electrodes are coated on both ends of the electrothermal functional layer and dried to finally obtain Figure 1 The illustrated embodiment is an electrothermal composite film for deicing and lightning protection of wind turbine blades.

[0033] like Figure 4 As shown, the second object of the present invention is to provide a wind turbine blade 22, comprising: a wind turbine blade 22, a lightning rod 44 on the outer surface of the wind turbine blade 22, a grounding lead 55 electrically connected to one end of the lightning rod 44, an electrothermal composite film 11 based on the electrothermal composite film 11 for deicing and lightning protection of wind turbine blades at the front end of the wind turbine blade 22, and an electrode lead 66 electrically connected to one end of the electrothermal composite film 11.

[0034] In the above scheme, a lightning receptor is provided on the outer surface of the wind turbine blade. It is a key component of the lightning protection system and is used to receive and guide lightning current. One end of the lightning receptor is electrically connected to the grounding lead, which leads the lightning current into the ground, thereby preventing lightning from damaging the wind turbine blades and wind turbine equipment. An electrothermal composite film is installed at the front end of the wind turbine blade. This layer of film not only has a de-icing function, but also provides certain protection in lightning weather. One end of the electrothermal composite film is electrically connected to the electrode lead, which is used to connect the power supply to the electrothermal functional layer to achieve electrical heating of the electrothermal composite film.

[0035] Wind turbine blades combine lightning arresters, grounding leads, and electrothermal composite films to provide all-round protection for wind turbine equipment. The deicing function of the electrothermal composite film can ensure that wind turbine blades can operate normally even in severe weather, thereby improving the power generation efficiency of wind turbine equipment. Through reasonable electrical connections and lightning protection design, the safety of wind turbine blades in lightning weather has been significantly improved.

[0036] The present invention provides an application of an electrothermal composite film for deicing and lightning protection of wind turbine blades, including the electrothermal composite film for deicing and lightning protection of wind turbine blades described in any one of the above schemes. The application of the electrothermal composite film for deicing and lightning protection of wind turbine blades includes: a wind turbine blade, a lightning receptor on the outer surface of the wind turbine blade, a grounding lead electrically connected to one end of the lightning receptor, an electrothermal composite film for deicing and lightning protection of wind turbine blades at the front end of the wind turbine blade, and an electrode lead electrically connected to one end of the electrothermal composite film for deicing and lightning protection of wind turbine blades.

[0037] As a preferred solution, the upper end of the lightning receptor is bonded to the electrothermal composite film close to the edge, and a gap of less than 1 mm is retained; this design is to ensure that the lightning receptor can effectively receive and guide lightning current, while avoiding direct contact with the electrothermal composite film to cause short circuit or affect the electrothermal function. Retaining a gap of less than 1 mm can ensure that when lightning strikes, the current can smoothly flow through the lightning receptor to the grounding lead without reducing the conductive efficiency or increasing the risk of breakdown due to excessive gaps. In addition, bonding close to the edge can also ensure the structural stability of the lightning receptor and the electrothermal composite film, preventing loosening or falling off under the action of wind and other external forces.

[0038] The electric heating composite film is adhered to the outer surface of the wind turbine blade using insulating glue. The insulating glue can ensure electrical isolation between the electric heating composite film and the outer surface of the wind turbine blade, preventing current leakage through unexpected paths, thereby protecting the electrical safety of the electric heating composite film and the wind turbine blade. At the same time, the insulating glue can also provide sufficient adhesion to ensure that the electric heating composite film is firmly installed on the wind turbine blade. When the electric heating functional layer and the electrode are facing the outer surface of the wind turbine blade, it can ensure that the electric heating composite film can effectively transfer heat to the ice and snow on the surface of the blade when working, achieving rapid deicing.

[0039] The electrodes of the electrothermal composite membrane are electrically connected to the electrode leads. This design is to realize the electrical heating function of the electrothermal composite membrane. The electrode is the interface between the electrothermal composite membrane and the power supply. Connecting the electrode to the power supply through the electrode lead can ensure that the electrothermal functional layer can generate heat when powered on. The selection and design of the electrode lead needs to take into account the efficiency, safety and reliability of current transmission to ensure that the electrothermal composite membrane can work stably and efficiently. In addition, the electrical connection between the electrode and the electrode lead also needs to ensure good contact performance and durability to cope with various environmental and stress conditions during long-term operation.

[0040] The specific preparation method of the above-mentioned wind turbine blade 22 comprises the following steps: The above-obtained electrothermal composite film for deicing and lightning protection of wind turbine blades is prepared according to Figure 4The solution in the paper is glued to the surface of the blade, where the electrothermal composite film with array metal guide plates is laid on the leading edge of the blade, while the electrothermal composite film without array metal guide plates is laid in the middle and rear sections of the blade. This is because most lightning strikes occur at the leading edge of the blade, and lightning protection is not required in the middle and rear sections of the blade to reduce costs and reduce blade weight. At the same time, the lightning receptor is set at the position where the array metal guide plates are, and the upper end of the lightning receptor is bonded to the electrothermal composite film used for wind turbine blade deicing and lightning protection close to the edge, and a gap of less than 1 mm is retained. The lower end of the lightning receptor is electrically connected to the grounding lead. The electrode of the electrothermal composite film is electrically connected to the electrode lead.

[0041] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0042] Embodiment 1: use Figure 2 The distribution scheme of the medium array metal guide plate is that the metal guide plate is made of aluminum alloy, and the spacing between each metal guide plate is kept at 1 mm; the high insulation base material is polyurethane, and the thickness is about 1 mm; the electric heating functional layer is an epoxy resin-based composite material. The specific preparation process is as follows: 30 parts of spherical graphite, 10 parts of conductive carbon black and 10 parts of silver-coated copper powder were weighed and added to 50 parts of epoxy resin, and stirred at 1000 rpm for 2 h to make them evenly mixed. Then 10 parts of triethylenetetramine were added and stirred for 1 h. After mixing evenly, it was coated on one side of the polyurethane high-insulation substrate without an array-type metal guide plate by screen printing, and then cured at 120°C for 2 h to obtain an epoxy resin-based electric heating functional layer. Then, conductive copper paste was coated on both ends of the electric heating functional layer and dried to obtain Figure 1 The illustrated embodiment is an electrothermal composite film for deicing and lightning protection of wind turbine blades.

[0043] The above-obtained electrothermal composite film for deicing and lightning protection of wind turbine blades is prepared according to Figure 4 The solution in the paper is glued to the surface of the blade, where the electrothermal composite film with array metal guide plates is laid on the leading edge of the blade, while the electrothermal composite film without array metal guide plates is laid in the middle and rear sections of the blade. This is because most lightning strikes occur at the leading edge of the blade, and lightning protection is not required in the middle and rear sections of the blade to reduce costs and reduce blade weight. At the same time, the lightning receptor is set at the position where the array metal guide plates are, and the upper end of the lightning receptor is bonded to the electrothermal composite film used for wind turbine blade deicing and lightning protection close to the edge, and a gap of less than 1 mm is retained. The lower end of the lightning receptor is electrically connected to the grounding lead. The electrode of the electrothermal composite film is electrically connected to the electrode lead.

[0044] Then will Figure 4The wind turbine blades were subjected to lightning strike tests, with the angle between the blades and the horizontal plane being 5° and the discharge occurring 20 times. The results showed that all 20 lightning arcs fell on the array-type metal guide vanes, and no breakdown occurred on the blade body.

[0045] Embodiment 2: use Figure 3 The distribution scheme of the medium array metal guide plate is that the metal guide plate is made of titanium alloy, and the spacing between each metal guide plate is kept at 1 mm; the high insulation base material is fluororubber, and the thickness is about 1 mm; the electric heating functional layer is a polyethersulfone-based composite material. The specific preparation process is as follows: 60 parts of polyethersulfone resin (PES) were weighed and dissolved in 300 parts of N-methylpyrrolidone, heated and stirred at 80°C for 6 h, and after PES was completely dissolved, 20 parts of conductive carbon black, 15 parts of graphite, 3 parts of multi-walled carbon nanotubes, and 2 parts of graphene were added to the PES solution, stirred at 1200 rpm for 3 h, and after mixing evenly, it was coated on one side of the fluororubber high insulation substrate without array metal guide plate by blade coating, and then dried at 80°C for 12 h to obtain a polyethersulfone resin-based electric heating functional layer, and then conductive silver paste was coated on both ends of the electric heating functional layer and dried to finally obtain an electric heating composite membrane for deicing and lightning protection of wind turbine blades.

[0046] The above-obtained electrothermal composite film for deicing and lightning protection of wind turbine blades is prepared according to Figure 5 The scheme in the figure is glued to the blade surface. The lightning receptor is set at the position where the array metal guide plate is located. The upper end of the lightning receptor is glued to the electric heating composite film used for wind turbine blade deicing and lightning protection close to the edge, and a gap of less than 1 mm is retained. The lower end of the lightning receptor is electrically connected to the grounding lead. The electrode of the electric heating composite film is electrically connected to the electrode lead.

[0047] Then will Figure 5 The wind turbine blades were subjected to lightning strike tests, with the angle between the blades and the horizontal plane being 10° and the discharge occurring 10 times. The results showed that all 10 lightning arcs fell on the array-type metal guide vanes, and no breakdown occurred on the blade body.

[0048] Embodiment 3: use Figure 2 The distribution scheme of the medium array metal guide plate is that the metal guide plate is made of titanium alloy, and the spacing between each metal guide plate is kept at 1 mm; the high insulation base material is polyurethane, and the thickness is about 1 mm; the electric heating functional layer is an epoxy resin-based composite material. The specific preparation process is as follows: 20 parts of spherical graphite, 10 parts of carbon fiber and 10 parts of pyrolytic carbon black were weighed and added to 60 parts of epoxy resin, and stirred at 1100 rpm for 1 hour to make them evenly mixed, and then 10 parts of triethylenetetramine were added and stirred for 1 hour. After mixing evenly, it was coated on one side of the polyurethane high insulation substrate without array metal guide plate by screen printing, and then cured at 120°C for 2 hours to obtain the epoxy resin-based electric heating functional layer, and then conductive copper paste was coated on both ends of the electric heating functional layer and dried to finally obtain Figure 1 The illustrated embodiment is an electrothermal composite film for deicing and lightning protection of wind turbine blades.

[0049] The above-obtained electrothermal composite film for deicing and lightning protection of wind turbine blades is prepared according to Figure 4 The solution in the paper is glued to the surface of the blade, where the electrothermal composite film with array metal guide plates is laid on the leading edge of the blade, while the electrothermal composite film without array metal guide plates is laid in the middle and rear sections of the blade. This is because most lightning strikes occur at the leading edge of the blade, and lightning protection is not required in the middle and rear sections of the blade to reduce costs and reduce blade weight. At the same time, the lightning receptor is set at the position where the array metal guide plates are, and the upper end of the lightning receptor is bonded to the electrothermal composite film used for wind turbine blade deicing and lightning protection close to the edge, and a gap of less than 1 mm is retained. The lower end of the lightning receptor is electrically connected to the grounding lead. The electrode of the electrothermal composite film is electrically connected to the electrode lead.

[0050] Then will Figure 4 The wind turbine blades were subjected to lightning strike tests, with the angle between the blades and the horizontal plane being 5° and discharges being performed 15 times. The results showed that all 15 lightning arcs fell on the array-type metal guide vanes, and there was no breakdown of the blade body.

[0051] Embodiment 2: use Figure 3 The distribution scheme of the medium array metal guide plate is that the metal guide plate is made of aluminum alloy, and the spacing between each metal guide plate is kept at 1 mm; the high insulation base material is fluororubber, and the thickness is about 1 mm; the electric heating functional layer is a polyethersulfone-based composite material. The specific preparation process is as follows: 50 parts of polyethersulfone resin (PES) were weighed and dissolved in 300 parts of N-methylpyrrolidone, heated and stirred at 80°C for 6 h, and after PES was completely dissolved, 20 parts of conductive carbon black, 15 parts of conductive carbon black, 8 parts of multi-walled carbon nanotubes, and 7 parts of copper powder were added to the PES solution, stirred at 1100 rpm for 2 h, and mixed evenly. After that, it was coated on one side of the fluororubber high insulation substrate without array metal guide plate by a doctor blade method, and then dried at 80°C for 12 h to obtain a polyethersulfone resin-based electric heating functional layer. Conductive silver paste was then coated on both ends of the electric heating functional layer and dried to finally obtain an electric heating composite membrane for deicing and lightning protection of wind turbine blades.

[0052] The above-obtained electrothermal composite film for deicing and lightning protection of wind turbine blades is prepared according to Figure 5 The scheme in the figure is glued to the blade surface. The lightning receptor is set at the position where the array metal guide plate is located. The upper end of the lightning receptor is glued to the electric heating composite film used for wind turbine blade deicing and lightning protection close to the edge, and a gap of less than 1 mm is retained. The lower end of the lightning receptor is electrically connected to the grounding lead. The electrode of the electric heating composite film is electrically connected to the electrode lead.

[0053] Then will Figure 5 The wind turbine blades were subjected to lightning strike tests, with the angle between the blades and the horizontal plane being 10° and discharges being performed 18 times. The results showed that all 18 lightning arcs fell on the array-type metal guide vanes, and there was no breakdown of the blade body.

[0054] The embodiments described above are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. An electrothermal composite film for deicing and lightning protection of wind turbine blades, characterized in that: include: An electrothermal functional layer, an electrode on one side of the electrothermal functional layer, a high-insulation substrate on the other side of the electrothermal functional layer, and an array of metal guide plates on one side of the high-insulation substrate.

2. The electrothermal composite film for deicing and lightning protection of wind turbine blades according to claim 1, characterized in that: The material of the electrode is one or more of copper, aluminum, nickel, stainless steel, and silver; The electrothermal functional layer is one or more of woven carbon fiber and polymer-based electrothermal composite material.

3. The electrothermal composite film for deicing and lightning protection of wind turbine blades according to claim 2 is characterized in that: The polymer-based electrothermal composite material consists of a polymer matrix and a conductive filler; The polymer matrix includes one or more of polyimide, polysulfone, polyphenylene sulfide, polyetheretherketone, polyethersulfone, polydimethylsiloxane, polyurethane, and epoxy resin.

4. The electrothermal composite film for deicing and lightning protection of wind turbine blades according to claim 3 is characterized in that: The conductive filler includes one or more of graphite, carbon fiber, silver nanowire, conductive carbon black, copper powder, aluminum powder, iron powder, nickel powder, silver powder, silver-coated copper powder, multi-walled carbon nanotubes, single-walled carbon nanotubes, graphene and pyrolytic carbon black.

5. The electrothermal composite film for deicing and lightning protection of wind turbine blades according to claim 1 is characterized in that: The high-insulation base material is one or more of polyurethane rubber and fluororubber.

6. The electrothermal composite film for deicing and lightning protection of wind turbine blades according to claim 1, characterized in that: The array-type metal guide plate is made of one or more of stainless steel, aluminum alloy, and titanium alloy.

7. A wind turbine blade, characterized in that: The lightning rod on the outer surface of the wind turbine blade, the grounding lead electrically connected at one end of the lightning rod, the electrothermal composite film for deicing and lightning protection of wind turbine blades based on any one of claims 1 to 4 at the front end of the wind turbine blade, and the electrode lead electrically connected at one end of the electrothermal composite film.

8. The wind turbine blade according to claim 7, characterized in that: The upper end of the lightning receptor is bonded to the electric heating composite film for deicing and lightning protection of wind turbine blades close to the edge, and a gap of less than 1 mm is retained, and the lower end of the lightning receptor is electrically connected to the grounding lead.

9. The wind turbine blade according to claim 7, characterized in that: The electrothermal composite film for deicing and lightning protection of wind turbine blades is adhered to the outer surface of the wind turbine blade by using insulating glue, wherein the electrothermal functional layer and the electrode face the outer surface of the wind turbine blade.

10. The wind turbine blade according to claim 7, characterized in that: The electrodes of the electrothermal composite film for deicing and lightning protection of wind turbine blades are electrically connected to the electrode leads.

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