Nickel-titanium-based alloy enhanced wind power blade as well as preparation method and application of nickel-titanium-based alloy enhanced wind power blade

Abstract

The invention discloses a nickel-titanium-based alloy enhanced wind power blade as well as a preparation method and application of the nickel-titanium-based alloy enhanced wind power blade. Innovation and breakthrough are achieved by embedding the pretreated nickel-titanium-based alloy wire into the wind power blade material. By means of the shape memory effect or the hyperelasticity of the nickel-titanium-based alloy wires, the strength and rigidity of the wind power blade are enhanced, the anti-fatigue and anti-impact performance is enhanced, the structural stability and reliability of the blade are improved, and the service life is prolonged. Meanwhile, on the basis of the linear relation between the resistivity and the strain of the nickel-titanium-based alloy wires, resistivity signals are monitored in real time, the fault degree is evaluated according to the fluctuation degree of the resistivity signals, and by means of the distribution form of the alloy wires in the blade, the fault area is accurately positioned through an array method. The method can effectively improve the fault monitoring efficiency and accuracy, avoids fault accumulation, reduces the operation and maintenance cost, improves the strength and rigidity of the wind power blade, provides powerful guarantee for stable operation of a wind power generation system, and has remarkable economic benefits and application values.

Description

Technical Field

[0001] The present invention belongs to the field of wind turbine blades and nickel-titanium (NiTi) based alloys, and in particular relates to a nickel-titanium based alloy reinforced wind turbine blade and a preparation method and application thereof. Background Art

[0002] As a clean and renewable form of energy, wind power generation is of great significance for reducing air pollution and addressing climate change. With the growing global demand for sustainable energy, the wind power industry has developed rapidly. However, the stability of wind turbines, especially the reliability of wind turbine blades, is still one of the important factors affecting the efficiency and safety of wind power generation. During long-term operation, wind turbine blades are exposed to strong winds, humidity, high day-night temperature differences and other harsh external environments, which are prone to cracks, fatigue damage or deformation. These faults not only affect the power generation efficiency of wind turbine blades, but may also cause mechanical failures or blade breakage, thereby threatening the safety and reliability of the equipment (China Electric Power, 2023, 56(10):80-95). Therefore, timely and accurate monitoring and repair of wind turbine blade faults is the key to ensuring the stable operation of wind power generation systems. Currently, wind turbine blade fault monitoring methods, such as ultrasonic monitoring, infrared thermal imaging monitoring, and vibration analysis, are effective under certain conditions, but they also have many limitations, such as: (1) Low monitoring efficiency. Monitoring methods mostly rely on manual operation and judgment. The process is cumbersome and time-consuming, affecting the normal operation of wind turbines; (2) They are greatly affected by the environment. For example, ultrasonic and infrared monitoring are easily affected by environmental factors such as temperature and humidity, resulting in reduced detection accuracy; (3) They are unable to accurately locate subtle faults. Existing methods are difficult to effectively monitor tiny cracks or early damage on the blade surface, missing the best time for repair, resulting in the accumulation of faults and ultimately causing irreversible damage; (4) The operation and maintenance costs are high. Regular inspections and maintenance require a lot of human resources. Repair work usually requires a professional team to carry out complex repairs, which increases the operation and maintenance costs. Recently, researchers have disclosed an online testing and diagnosis method for the vibration characteristics of wind turbine blades. By installing vibration sensors at key locations on the blades, signal processing technology is used to evaluate the impact of wind speed and temperature environmental factors on the vibration characteristics, and a deep learning model is designed to identify different types of damage such as erosion, cracks, and impacts. Based on real-time data streams and historical trends, the warning threshold is automatically adjusted (CN202410874016.9). The above patented technology is based on damage prediction and vibration mode analysis to develop preventive maintenance plans. However, online monitoring of the entire blade vibration cannot accurately locate the damage or fault location, making it difficult to improve the maintenance efficiency of wind turbine blades.

[0003] In addition, the strength and stiffness of wind turbine blades are also important factors affecting their long-term stable operation. At present, wind turbine blades are mostly made of polymer composite materials with low strength and stiffness. They are prone to fatigue damage and structural damage under storms and extreme weather conditions, affecting the overall power generation efficiency and safety. Therefore, improving the strength and stiffness of wind turbine blades is also an important measure to extend their service life and improve power generation efficiency. Recently, the published patented technology has attempted to use carbon fiber reinforced polyamide composite materials to strengthen wind turbine blades. By using the in-situ carbonization method of polyimide, an interconnected network is constructed in the carbon fiber. The stress-conducting effect of the carbon fiber interconnected network is utilized to make the composite material of the patented technology have good mechanical properties (CN202311620806.6). While the above patented technology effectively improves the mechanical properties of composite materials for wind turbine blades, it is accompanied by problems such as the extension and complication of the process flow and reduced production efficiency. Summary of the invention

[0004] In order to overcome the shortcomings of existing wind turbine blades that are easily affected by the environment and have insufficient strength and stiffness, as well as the limitations of fault monitoring methods, the primary purpose of the present invention is to provide a method for preparing nickel-titanium-based alloy-reinforced wind turbine blades. By embedding pretreated nickel-titanium-based alloy wires into wind turbine blades, using their shape memory effect or superelastic properties, force is applied to the inside of the wind turbine blades to improve the strength and stiffness of the blades. The addition of nickel-titanium-based alloy wires not only enhances the fatigue resistance and impact resistance of the blades, but also improves the structural stability and long-term reliability of the blades, effectively extending the service life of the blades and reducing the operation and maintenance costs of the wind power system.

[0005] The second object of the present invention is to provide a wind turbine blade reinforced with a nickel-titanium based alloy prepared by the above preparation method.

[0006] The third purpose of the present invention is to provide a method for monitoring and locating wind turbine blade faults reinforced by nickel-titanium alloy. Through the linear strain-resistivity relationship data and layout analysis of nickel-titanium alloy wires, accurate monitoring, accurate positioning and digital evaluation of wind turbine blade fault areas can be achieved, greatly improving the efficiency and accuracy of wind turbine blade fault monitoring and reducing operation and maintenance costs. This method can effectively avoid the accumulation of faults and the occurrence of irreversible damage.

[0007] A fourth object of the present invention is to provide a nickel-titanium-based alloy reinforced wind turbine blade fault monitoring and positioning system, which is safe, reliable and economical.

[0008] The primary purpose of the present invention is achieved through the following technical solutions:

[0009] A method for preparing a nickel-titanium-based alloy reinforced wind turbine blade comprises the following steps:

[0010] (1) Pretreatment of the nickel-titanium alloy wire: first, the surface of the nickel-titanium alloy wire is treated with an acid solution, and then subjected to a cooling-deformation pretreatment or a direct deformation pretreatment to obtain a pretreated nickel-titanium alloy wire;

[0011] (2) embedding the pretreated nickel-titanium alloy wires into wind turbine blades in parallel or crosswise manner to prepare nickel-titanium alloy reinforced wind turbine blades;

[0012] The cooling-deformation pretreatment mentioned in step (1) refers to cooling the nickel-titanium alloy wire to a state where the matrix is ​​martensite, and then performing a stretching deformation treatment; the direct deformation pretreatment mentioned in step (1) refers to directly performing a stretching deformation treatment on the nickel-titanium alloy wire in the austenite state; wherein the stretching strain is 1% to 8%.

[0013] Preferably, the acid solution is one of HNO3 solution, HCl solution, H2SO4 solution, HF and HNO3 mixed solution, wherein the mass content of acid in the acid solution is 10% to 80%, and the acid solution treatment time is 15s to 60s.

[0014] Preferably, the nickel-titanium-based alloy wire in step (1) is one of nickel-titanium alloy wire, nickel-titanium-copper alloy wire, nickel-titanium-iron alloy wire, nickel-titanium-niobium alloy wire and nickel-titanium-zirconium alloy wire, the grain size of the nickel-titanium-based alloy wire is in the range of 10 nm to 1000 nm, the diameter of the alloy wire is in the range of 0.1 mm to 3 mm, and the distribution density of the alloy wire in the wind turbine blade matrix material is in the range of 8 to 10 4 Root / cm 2 (Based on alloy wire cross-section statistics).

[0015] Preferably, the material used to make the wind turbine blade in step (2) is at least one of fiber and high-performance resin.

[0016] Preferably, when the material used to make the wind turbine blade in step (2) is fiber, the fiber is one of carbon fiber, glass fiber or natural fiber; when the material used to make the wind turbine blade in step (2) is high-performance resin, the high-performance resin is epoxy resin or polyimide.

[0017] The purpose of surface treatment of the nickel-titanium-based alloy wire with an acid solution is to remove surface debris and an oxide layer, increase the surface roughness of the nickel-titanium-based alloy wire, and improve the bonding strength between the nickel-titanium-based alloy wire and the wind turbine blade material.

[0018] The second object of the present invention is achieved by the following technical solutions:

[0019] A nickel-titanium based alloy reinforced wind turbine blade is prepared by the above preparation method.

[0020] The third object of the present invention is achieved by the following technical solutions:

[0021] A method for monitoring and locating faults of a wind turbine blade reinforced with a nickel-titanium-based alloy comprises the following steps:

[0022] a. Before assembly, the resistivity of the nickel-titanium wire in the nickel-titanium-based alloy-reinforced wind turbine blade is measured to obtain the original resistivity signal R0 of the nickel-titanium alloy wire;

[0023] b. After the wind turbine blades are assembled and put into service, the resistivity of the nickel-titanium alloy wire in the nickel-titanium alloy-reinforced wind turbine blades is monitored in real time, and the resistivity signal R1 at this time is compared and analyzed with the resistivity signal R0 in step a to obtain the fluctuation value A of the resistivity signal, wherein A=R1-R0R0×100%;

[0024] c. According to the resistivity fluctuation signal of the nickel-titanium alloy wire monitored in step b, the fault degree of the nickel-titanium alloy reinforced wind turbine blade is determined and the fault position is accurately located.

[0025] Preferably, the evaluation of the fault degree in step c is carried out based on the fluctuation degree of the resistivity signal. When the fluctuation degree of the resistivity signal is greater than 15% and less than 25%, it is judged as a minor fault; when the fluctuation degree of the resistivity signal is greater than 25% and less than 40%, it is judged as a moderate fault; when the fluctuation degree of the resistivity signal is greater than 40%, it is judged as a serious fault.

[0026] Preferably, the precise positioning described in step c is based on the resistivity signal fluctuation degree information of the nickel-titanium-based alloy wire. From all the monitored resistivity signal fluctuations, 3 to 12 nickel-titanium-based alloy wires with the largest resistivity signal fluctuations are selected, and combined with the arrangement of the nickel-titanium-based alloy wires, an array method is used to obtain precise positioning of the fault position.

[0027] The fourth object of the present invention is achieved by the following technical solutions:

[0028] A nickel-titanium-based alloy reinforced wind turbine blade fault monitoring and positioning system, comprising a resistivity signal acquisition module, a resistivity signal fluctuation analysis module, a fault determination module and a fault positioning module;

[0029] The resistivity signal acquisition module is used to acquire the original resistivity signal R0 and the real-time monitoring resistivity signal R1 of the nickel-titanium alloy wire in the nickel-titanium alloy-reinforced wind turbine blade;

[0030] The resistivity signal fluctuation analysis module is used to compare and analyze the collected real-time monitoring resistivity signal R1 with the original resistivity signal R0 to obtain the fluctuation value A of the resistivity signal, where A=R1-R0R0×100%;

[0031] The fault determination module is used to determine the degree of fault according to the magnitude of the fluctuation value A;

[0032] The fault location module is used to select 3 to 12 nickel-titanium-based alloy wires with the largest resistivity signal fluctuations from all monitored resistivity signal fluctuations according to the resistivity signal fluctuation degree information of the nickel-titanium-based alloy wires, and use an array method to accurately locate the fault position in combination with the arrangement of the nickel-titanium-based alloy wires.

[0033] The principle of the present invention is:

[0034] The strength and stiffness of wind turbine blades are improved by nickel-titanium alloy wires, and accurate fault monitoring is achieved. Specifically, the present invention utilizes the shape memory effect or superelastic properties of nickel-titanium-based alloy wires, and the linear strain-resistivity relationship to embed the pre-treated nickel-titanium alloy wires into wind turbine blades, thereby improving the strength and stiffness of wind turbine blades, and enhancing the fatigue resistance, impact resistance and overall structural stability of wind turbine blades. At the same time, once a blade fails, such as cracks, large deformations, etc., the stress and strain changes in the fault area will cause the strain of the alloy wire to change, and the resistivity will change accordingly. The patented technology of the present invention monitors the resistivity signal, analyzes the degree of fluctuation of the resistivity signal to determine the degree of fault, and can detect tiny cracks or local damage of wind turbine blades at an early stage, reducing the accumulation and irreversible damage of wind turbine blade damage. Combined with the parallel or cross distribution of nickel-titanium-based alloy wires in wind turbine blades, multiple nickel-titanium-based alloy wires with large resistivity signal fluctuations are selected, and an array positioning method is used to accurately determine the fault location based on its layout information, thereby overcoming the limitations of traditional monitoring methods and improving fault monitoring efficiency and accuracy.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] The technology of the present invention is an innovative technology that combines the dual functions of wind turbine blade structure enhancement and fault monitoring. In terms of improving the strength and stiffness of blades, the unique properties of nickel-titanium-based alloy wire (shape memory effect or superelasticity) are used to effectively enhance its fatigue resistance and impact resistance. Compared with blades made of traditional polymer composite materials, it can better cope with storms and extreme weather, reduce the risk of structural damage, ensure power generation efficiency and safety, extend the service life of blades, and reduce the high cost caused by frequent blade replacement. In terms of fault monitoring, the monitoring method based on the linear relationship between strain and resistivity of nickel-titanium-based alloy wire overcomes the shortcomings of traditional monitoring methods such as ultrasound and infrared thermal imaging, which are greatly affected by the environment, have low detection efficiency, and are difficult to accurately locate subtle faults. It can accurately locate the fault area, realize digital evaluation, greatly improve the accuracy and efficiency of fault monitoring, timely discover and deal with blade problems, avoid irreversible damage caused by fault accumulation, effectively reduce the cost of operation and maintenance manpower and material resources, and provide a solid guarantee for the stable, efficient and safe operation of wind power generation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is the loading and unloading curve of the nickel-titanium alloy wire in Example 1 (the recovery of the superelastic nickel-titanium alloy wire after loading will exert a force on the wind turbine blade matrix material);

[0038] Figure 2 This is the loading-unloading-heating curve of the nickel-titanium-niobium alloy wire in Example 3 (after loading-unloading-heating, the recovery of the nickel-titanium-niobium alloy wire with shape memory effect will exert force on the wind turbine blade matrix material). DETAILED DESCRIPTION

[0039] The present invention is further described in detail below in conjunction with specific examples, but the embodiments of the present invention are not limited thereto. The materials used in the examples of the present invention can all be purchased commercially.

[0040] The nickel-titanium alloy wires in the embodiments and comparative examples of the present invention can be directly purchased from the market. The HNO3 solution, HSO4 solution, HCl solution, and mixed acid solution of HNO3 and HF used in the embodiments and comparative examples of the present invention can be directly purchased from the market or purchased and mixed, and the mass content of the acid in the acid solution is 10% to 80%.

[0041] The preparation method of the nickel-titanium-copper alloy wire, the nickel-titanium-iron alloy wire, the nickel-titanium-niobium alloy wire and the nickel-titanium-zirconium alloy wire in the present invention comprises the following preparation steps:

[0042] (1) Using high-purity titanium, high-purity nickel, high-purity copper (or high-purity iron, high-purity niobium, high-purity zirconium) raw materials, the purity of each of which is not less than 99.5% (mass percentage); when the alloy wire is nickel-titanium alloy wire, the mass percentage of high-purity nickel is in the range of 51% to 59%, the sum of oxygen and nitrogen elements is ≤0.06%, and the balance is pure titanium; when the alloy wire is nickel-titanium copper, nickel-titanium iron, nickel-titanium niobium, nickel-titanium zirconium, the mass percentage of high-purity nickel is in the range of 48% to 56%, the mass percentage of high-purity copper (or iron, niobium, zirconium) is in the range of 2% to 10%, the sum of oxygen and nitrogen elements is ≤0.06%, and the balance is pure titanium; a method combining induction melting and vacuum consumable melting is used to obtain a high-purity, high-uniformity alloy ingot;

[0043] (2) obtaining alloy bars by forging and rolling, and subjecting the alloy bars to hot drawing and intermediate annealing;

[0044] (3) Continue to draw at room temperature to obtain a finished alloy wire, anneal and straighten the finished product, and finally obtain the target nickel-titanium-based alloy wire.

[0045] Example 1

[0046] (1) Selection of nickel-titanium alloy wire: A nickel-titanium alloy wire with a grain size of 10-100 nm and a diameter of 0.5 mm was selected as the embedding material. The linear strain-resistivity relationship of the nickel-titanium alloy wire is y=0.07x+1.05, where y is the resistivity in Ω·μm and x is the strain in %.

[0047] (2) Surface pretreatment of nickel-titanium alloy wire: The nickel-titanium alloy wire was treated with a 25% by mass HNO3 solution for 20 seconds; the alloy wire was directly stretched and deformed in the austenitic state, and the tensile strain was set to 4-5%;

[0048] (3) Embedding nickel-titanium alloy wires into wind turbine blades: The pre-treated nickel-titanium alloy wires are embedded in the wind turbine blade material mainly composed of epoxy resin in a parallel and cross-distributed manner, with an embedding density of 80 wires / cm 2 ; After the embedding is completed, the loaded nickel-titanium alloy wire is unloaded, and the force is applied to the wind turbine blade material through the superelastic restoring force. Through testing, it is found that the strength (tensile strength) and stiffness (elastic modulus) of the wind turbine blades without and with embedded nickel-titanium alloy wire ranges are: 100MPa-160MPa and 3.2GPa-5.6GPa, 220MPa-350MPa and 4.9GPa-8.6GPa respectively. Figure 1 is the loading and unloading curve (superelasticity) of the nickel-titanium alloy wire in Example 1;

[0049] (4) Fault monitoring of wind turbine blades: Before the wind turbine blades are assembled, the resistivity of the embedded nickel-titanium alloy wire is measured, and the original resistivity of the nickel-titanium alloy wire is obtained as R0 = 1.05Ω·μm; after the wind turbine blades are assembled and put into service, the resistivity of the nickel-titanium alloy wire in the nickel-titanium alloy-reinforced wind turbine blades is monitored in real time, and the real-time monitoring resistivity R1 is obtained, and the fluctuation value A of the resistivity signal is calculated, where A = R1-R0R0×100%; during the service of the wind turbine blades, the resistivity signals of 5 nickel-titanium alloy wires are monitored to change significantly, and A reaches 15%-20%, and it is determined that the wind turbine blade has a minor fault. An actual inspection of the wind turbine blades revealed that a small number of microcracks appeared on the surface of the wind turbine blades. The fault monitoring judgment result is consistent with the actual observation result;

[0050] (5) Fault location of wind turbine blades: Based on the known arrangement of nickel-titanium alloy wires and the arrangement positions of the five nickel-titanium alloy wires in step (4), an array method is used to obtain the fault location. The fault location obtained by the nickel-titanium alloy wires is consistent with the fault location found by actual inspection.

[0051] Example 2

[0052] (1) Selection of nickel-titanium-copper alloy wire: A nickel-titanium-copper alloy wire with a grain size of 500 nm and a diameter of 1 mm was selected as the embedding material. The linear strain-resistivity relationship of the nickel-titanium-copper alloy wire is y=0.05x+1.01, where y is the resistivity in Ω·μm and x is the strain in %.

[0053] (2) Surface pretreatment of nickel-titanium-copper alloy wire: The nickel-titanium-copper alloy wire was treated with a solution of 30% by mass HNO3 and 40% by mass HF for 15 seconds; the alloy wire was directly stretched and deformed in the austenitic state, and the tensile strain was set to 1-3%;

[0054] (3) Embedding nickel-titanium-copper alloy wire into wind turbine blades: The pre-treated nickel-titanium-copper alloy wire is embedded in the wind turbine blade material mainly composed of carbon fiber and epoxy resin in a cross-distributed form, with an embedding density of 20 wires / cm 2 After embedding, the loaded nickel-titanium-copper alloy wire is unloaded, and the wind turbine blade material is subjected to force through the superelastic restoring force. Through testing, it is found that the strength (tensile strength) and stiffness (elastic modulus) of the wind turbine blades without and with nickel-titanium-copper alloy wire are in the range of 800MPa-1200MPa and 180GPa-280GPa, 850MPa-1300MPa and 220GPa-320GPa respectively.

[0055] (4) Fault monitoring of wind turbine blades: Before the wind turbine blades are assembled, the resistivity of the embedded nickel-titanium-copper alloy wire is measured to obtain the original resistivity R0 of the nickel-titanium-copper alloy wire = 1.01Ω·μm; after the wind turbine blades are assembled and put into service, the resistivity of the nickel-titanium-copper alloy wire in the nickel-titanium-copper alloy-reinforced wind turbine blades is monitored in real time to obtain the real-time monitoring resistivity R1, and the fluctuation value A of the resistivity signal is calculated, where A = R1-R0R0×100%; during the service of the wind turbine blades, the resistivity signals of 6 nickel-titanium-copper alloy wires are monitored to change significantly, and A reaches 30%-35%, and it is determined that the wind turbine blade has a moderate fault. The actual inspection of the wind turbine blades found that material fell off on the surface of the wind turbine blades. The fault monitoring judgment result is consistent with the actual observation result;

[0056] (5) Fault location of wind turbine blades: Based on the known arrangement of nickel-titanium-copper alloy wires and the arrangement positions of the six nickel-titanium-copper alloy wires in step (4), an array method is used to obtain the fault location. The fault location obtained by the nickel-titanium-copper alloy wires is consistent with the fault location found by actual inspection.

[0057] Example 3

[0058] (1) Selection of nickel-titanium-niobium alloy wire: A nickel-titanium-niobium alloy wire with a grain size of 200-300 nm and a diameter of 0.8 mm was selected as the embedding material. The linear strain-resistivity relationship of the nickel-titanium-niobium alloy wire is y=0.08x+1.31, where y is the resistivity in Ω·μm and x is the strain in %.

[0059] (2) Surface pretreatment of the nickel-titanium-niobium alloy wire: the nickel-titanium-niobium alloy wire was treated with a solution containing 45% by mass of H2SO4 for 23 seconds; the nickel-titanium-niobium alloy wire was cooled to a state where the matrix was martensite, and then stretched and deformed, with the stretching strain being set to 6 to 8%;

[0060] (3) Embedding nickel-titanium-niobium alloy wire into wind turbine blades: The pre-treated nickel-titanium-niobium alloy wires are embedded in the wind turbine blade material mainly composed of glass fibers in a cross-distributed form, with an embedding density of 18 wires / cm 2 After embedding, the wind turbine blades are properly heated to transform the nickel-titanium-niobium alloy wire matrix from martensite to austenite, activate its shape memory effect, and apply force to the wind turbine blade material. Through testing, it is found that the strength (tensile strength) and stiffness (elastic modulus) of wind turbine blades without and with nickel-titanium-niobium alloy wires are in the range of 500MPa-600MPa and 50GPa-60GPa, 650MPa-850MPa and 62GPa-70GPa respectively. Figure 2 is the stress-strain curve (shape memory effect) of the nickel-titanium-niobium alloy wire in Example 3 during loading-unloading-heating;

[0061] (4) Fault monitoring of wind turbine blades: Before the wind turbine blades are assembled, the resistivity of the embedded nickel-titanium-niobium alloy wire is measured, and the original resistivity of the nickel-titanium-niobium alloy wire is obtained as R0 = 1.31Ω·μm; after the wind turbine blades are assembled and put into service, the resistivity of the nickel-titanium-niobium alloy wire in the nickel-titanium-niobium alloy-reinforced wind turbine blades is monitored in real time, and the real-time monitoring resistivity R1 is obtained. The fluctuation value A of the resistivity signal is calculated, where A = R1-R0R0×100%; during the service of the wind turbine blades, the resistivity signals of the three nickel-titanium-niobium alloy wires are monitored to have obvious changes, and A is greater than 45%, and it is determined that the wind turbine blade has a serious fault. The actual inspection of the wind turbine blades found that the surface of the wind turbine blades was fractured, and the fault monitoring judgment result was consistent with the actual observation result;

[0062] (5) Fault location of wind turbine blades: Based on the known arrangement of nickel-titanium-niobium alloy wires and the arrangement positions of the three nickel-titanium-niobium alloy wires in step (4), an array method is used to obtain the fault location. The fault location obtained by the nickel-titanium-niobium alloy wires is consistent with the fault location found by actual inspection.

[0063] Example 4

[0064] (1) Selection of nickel-titanium-iron alloy wire: A nickel-titanium-iron alloy wire with a grain size of 400-600 nm and a diameter of 1.6 mm was selected as the embedding material. The linear strain-resistivity relationship of the nickel-titanium-iron alloy wire is y=0.1x+1.17, where y is the resistivity in Ω·μm and x is the strain in %.

[0065] (2) Surface pretreatment of the nickel-titanium-iron alloy wire: The nickel-titanium-iron alloy wire was treated with a solution containing 25% by mass HCl for 45 seconds; the alloy wire was directly stretched and deformed in the austenitic state, and the tensile strain was set to 2-5%;

[0066] (3) Embedding nickel-titanium-iron alloy wire into wind turbine blades: The pre-treated nickel-titanium-iron alloy wire is embedded in a cross-distributed form into the wind turbine blade material mainly composed of natural fibers and polyimide, with an embedding density of 15 wires / cm 2 After embedding, the loaded nickel-titanium-iron alloy wire is unloaded, and the wind turbine blade material is subjected to force through the superelastic restoring force. Through testing, it is found that the strength (tensile strength) and stiffness (elastic modulus) of the wind turbine blades without and with nickel-titanium-iron alloy wire are in the range of 400MPa-600MPa and 30GPa-50GPa, 550MPa-700MPa and 40GPa-64GPa respectively.

[0067] (4) Fault monitoring of wind turbine blades: Before the wind turbine blades are assembled, the resistivity of the embedded nickel-titanium-iron alloy wire is measured to obtain the original resistivity R0 of the nickel-titanium-iron alloy wire = 1.17Ω·μm; after the wind turbine blades are assembled and put into service, the resistivity of the nickel-titanium-iron alloy wire in the nickel-titanium-iron alloy-reinforced wind turbine blades is monitored in real time to obtain the real-time monitoring resistivity R1, and the fluctuation value A of the resistivity signal is calculated, where A = R1-R0R0×100%; during the service of the wind turbine blades, the resistivity signals of the four nickel-titanium-iron alloy wires are monitored to change significantly, and A reaches 15%-20%, and it is determined that the wind turbine blade has a minor fault. An actual inspection of the wind turbine blades revealed that tiny cracks appeared on the surface of the wind turbine blades. The fault monitoring judgment result is consistent with the actual observation result;

[0068] (5) Fault location of wind turbine blades: Based on the known arrangement of nickel-titanium-iron alloy wires and the arrangement positions of the four nickel-titanium-iron alloy wires in step (4), an array method is used to obtain the fault location. The fault location obtained by the nickel-titanium-iron alloy wires is consistent with the fault location found by actual inspection.

[0069] Example 5

[0070] (1) Selection of nickel-titanium-zirconium alloy wire: A nickel-titanium-zirconium alloy wire with a grain size of 600-700 nm and a diameter of 3 mm was selected as the embedding material. The linear strain-resistivity relationship of the nickel-titanium-zirconium alloy wire is y=0.09x+1.43, where y is the resistivity in Ω·μm and x is the strain in %.

[0071] (2) Surface pretreatment of nickel-titanium-zirconium alloy wire: The nickel-titanium-zirconium alloy wire was treated with a solution of 25% by mass HF and 15% by mass HNO3 for 60 seconds; the nickel-titanium-zirconium alloy wire was cooled to a state where the matrix was martensite, and then stretched and deformed, and the stretching strain was set to 4-5%;

[0072] (3) Embedding nickel-titanium-zirconium alloy wire into wind turbine blades: The pre-treated nickel-titanium-zirconium alloy wires are embedded in the wind turbine blade material composed mainly of glass fiber and epoxy resin in a parallel and cross-distributed manner, with an embedding density of 5 wires / cm 2 After embedding, the wind turbine blades are properly heated to transform the nickel-titanium-zirconium alloy wire matrix from martensite to austenite, activate its shape memory effect, and apply force to the wind turbine blade material. Through testing, it is found that the strength (tensile strength) and stiffness (elastic modulus) of wind turbine blades without and with nickel-titanium-zirconium alloy wires are in the range of 430MPa-650MPa and 25GPa-43GPa, 550MPa-760MPa and 32GPa-55GPa respectively.

[0073] (4) Fault monitoring of wind turbine blades: Before the wind turbine blades are assembled, the resistivity of the embedded nickel-titanium-zirconium alloy wire is measured, and the original resistivity of the nickel-titanium-niobium alloy wire is obtained as R0 = 1.43Ω·μm; after the wind turbine blades are assembled and put into service, the resistivity of the nickel-titanium-zirconium alloy wire in the nickel-titanium-zirconium alloy-reinforced wind turbine blades is monitored in real time, and the real-time monitoring resistivity R1 is obtained, and the fluctuation value A of the resistivity signal is calculated, where A = R1-R0R0×100%; during the service of the wind turbine blades, the resistivity signals of 5 nickel-titanium-zirconium alloy wires are monitored to change significantly, and A is between 30% and 35%, and it is determined that the wind turbine blade has a moderate fault. The actual inspection of the wind turbine blades found that the surface of the wind turbine blades was kinked and had obvious cracks. The fault monitoring judgment result is consistent with the actual observation result;

[0074] (5) Fault location of wind turbine blades: Based on the known arrangement of nickel-titanium-zirconium alloy wires and the arrangement positions of the five nickel-titanium-zirconium alloy wires in step (4), an array method is used to obtain the fault location. The fault location obtained by the nickel-titanium-zirconium alloy wires is consistent with the fault location found by actual inspection.

[0075] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a wind turbine blade reinforced with a nickel-titanium-based alloy, characterized in that: The steps include: (1) Pretreatment of the nickel-titanium alloy wire: first, the surface of the nickel-titanium alloy wire is treated with an acid solution, and then subjected to a cooling-deformation pretreatment or a direct deformation pretreatment to obtain a pretreated nickel-titanium alloy wire; (2) embedding the pretreated nickel-titanium alloy wires into wind turbine blades in parallel or crosswise manner to prepare nickel-titanium alloy reinforced wind turbine blades; The cooling-deformation pretreatment mentioned in step (1) refers to cooling the nickel-titanium alloy wire to a state where the matrix is ​​martensite, and then performing a stretching deformation treatment; the direct deformation pretreatment mentioned in step (1) refers to directly performing a stretching deformation treatment on the nickel-titanium alloy wire in the austenite state; wherein the stretching strain is 1% to 8%.

2. The method for preparing a wind turbine blade reinforced with a nickel-titanium-based alloy according to claim 1, characterized in that: The acid solution is one of HNO3 solution, HCl solution, H2SO4 solution, and a mixed solution of HF and HNO3, wherein the mass content of the acid in the acid solution is 10% to 80%, and the acid solution treatment time is 15s to 60s.

3. The method for preparing a wind turbine blade reinforced with a nickel-titanium-based alloy according to claim 1, characterized in that: The nickel-titanium-based alloy wire in step (1) is one of nickel-titanium alloy wire, nickel-titanium-copper alloy wire, nickel-titanium-iron alloy wire, nickel-titanium-niobium alloy wire and nickel-titanium-zirconium alloy wire, the grain size of the nickel-titanium-based alloy wire is in the range of 10 nm to 1000 nm, the diameter of the alloy wire is in the range of 0.1 mm to 3 mm, and the distribution density of the alloy wire in the wind turbine blade matrix material is in the range of 8 to 10 4 Root / cm 2 .

4. The method for preparing a wind turbine blade reinforced with a nickel-titanium-based alloy according to claim 1, characterized in that: The material used to make the wind turbine blade in step (2) is at least one of fiber and high-performance resin.

5. The method for preparing a wind turbine blade reinforced with a nickel-titanium-based alloy according to claim 4, characterized in that: When the material used to make the wind turbine blade in step (2) is fiber, the fiber is one of carbon fiber, glass fiber or natural fiber; when the material used to make the wind turbine blade in step (2) is high-performance resin, the high-performance resin is epoxy resin or polyimide.

6. A nickel-titanium alloy reinforced wind turbine blade, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 5.

7. A method for monitoring and locating faults of wind turbine blades reinforced with nickel-titanium-based alloys according to claim 6, characterized in that: The steps include: a. Before assembly, the resistivity of the nickel-titanium wire in the nickel-titanium-based alloy-reinforced wind turbine blade is measured to obtain the original resistivity signal R0 of the nickel-titanium alloy wire; b. After the wind turbine blades are assembled and put into service, the resistivity of the nickel-titanium alloy wire of the nickel-titanium alloy-reinforced wind turbine blades is monitored in real time, and the resistivity signal R1 at this time is compared and analyzed with the resistivity signal R0 in step a to obtain the fluctuation value A of the resistivity signal, wherein A=R1-R0R0×100%; c. According to the resistivity fluctuation signal of the nickel-titanium alloy wire monitored in step b, the fault degree of the nickel-titanium alloy reinforced wind turbine blade is determined and the fault position is accurately located.

8. The method for monitoring and locating faults of wind turbine blades reinforced with nickel-titanium-based alloys according to claim 7, characterized in that: The evaluation of the fault degree in step c is based on the fluctuation degree of the resistivity signal. When the fluctuation degree of the resistivity signal is greater than 15% and less than 25%, it is judged as a minor fault. When the fluctuation degree of the resistivity signal is greater than 25% and less than 40%, it is judged as a moderate fault. When the fluctuation degree of the resistivity signal is greater than 40%, it is judged as a serious fault.

9. The method for monitoring and locating faults of wind turbine blades reinforced with nickel-titanium-based alloys according to claim 7, characterized in that: The precise positioning described in step c is based on the resistivity signal fluctuation degree information of the nickel-titanium based alloy wire. From all the monitored resistivity signal fluctuations, 3 to 12 nickel-titanium based alloy wires with the largest resistivity signal fluctuations are selected, and combined with the arrangement of the nickel-titanium based alloy wires, an array method is used to obtain precise positioning of the fault position.

10. A nickel-titanium-based alloy reinforced wind turbine blade fault monitoring and positioning system according to claim 6, characterized in that: It includes a resistivity signal acquisition module, a resistivity signal fluctuation analysis module, a fault determination module and a fault location module; The resistivity signal acquisition module is used to acquire the original resistivity signal R0 and the real-time monitoring resistivity signal R1 of the nickel-titanium alloy wire in the nickel-titanium alloy-reinforced wind turbine blade; The resistivity signal fluctuation analysis module is used to compare and analyze the collected real-time monitoring resistivity signal R1 with the original resistivity signal R0 to obtain the fluctuation value A of the resistivity signal, where A=R1-R0R0×100%; The fault determination module is used to determine the degree of fault according to the magnitude of the fluctuation value A; The fault location module is used to select 3 to 12 nickel-titanium-based alloy wires with the largest resistivity signal fluctuations from all monitored resistivity signal fluctuations according to the resistivity signal fluctuation degree information of the nickel-titanium-based alloy wires, and use an array method to accurately locate the fault position in combination with the arrangement of the nickel-titanium-based alloy wires.

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