Acoustic emission applied wind driven generator connecting bolt detection device

Abstract

The utility model discloses a wind driven generator connecting bolt detection device applying acoustic emission, which comprises a shell, a detection unit is arranged in the shell, a screw rod is attached to the top of the shell, and the outer wall of the screw rod is in threaded connection with a mounting frame. The utility model relates to the technical field of wind power generation, and discloses a wind driven generator connecting bolt detection device applying acoustic emission, which carries out on-line monitoring on a variable-pitch bearing and a connecting bolt of a wind driven generator through an acoustic emission technology by matching a shell, a detection unit, a mounting frame, a screw rod, a vacuum cavity and noise reduction cotton. The operation conditions of the variable-pitch bearing and the connecting bolt are automatically detected, and early fatigue failure of the variable-pitch bearing and the bolt is analyzed, judged and warned in advance, so that measures are taken to improve partial potential failure variable-pitch bearing stress in advance (such as polishing and derusting bolt holes and eliminating residual corrosion when the interior of the bolt is rusted), or the bolt is adjusted and replaced; the service life of the part is prolonged, and meanwhile the blade falling event is avoided.

Description

Technical Field

[0001] This utility model relates to the field of wind power generation technology, specifically to a wind turbine connecting bolt detection device that utilizes acoustic emission. Background Technology

[0002] With the rapid increase in the capacity and installed scale of wind power units, accidents such as tower collapse, rotor fall, and blade fall occur frequently. Fortunately, the operating environment of wind turbines is relatively remote, and they rarely cause casualties. However, the inconvenience of on-site handling (such as at sea and in mountainous areas), social impact (such as in sensitive areas and industrial parks), power generation and economic losses caused by these incidents also have a negative impact on the further development of wind power.

[0003] Based on the characteristics of blades falling off during wind turbine operation, the main causes are as follows: First, the pitch bearing cracks, causing separation of the inner and outer rings; second, the bolts connecting the pitch bearing to the hub break; third, the bolts connecting the pitch bearing to the blade break. For example, in a certain megawatt-class model, due to insufficient consideration of stress concentration and corrosion prevention in humid environments during its operational lifespan, rust appeared in the bolt holes connecting the blades and the pitch bearing after a period of operation, further concentrating stress and exacerbating the corrosion of the bolt holes, ultimately leading to cracking of the pitch bearing. The cracking process starts from the inside of the bolt hole and eventually penetrates through it, squeezing out the lubricating oil and subjecting the pitch bearing to alternating loads, eventually forming cracks on the pitch bearing. In existing megawatt-class wind turbine units, the bolts connecting the pitch bearing to the hub and the blades frequently break. Minor issues can be detected and addressed promptly by replacing some or all bolts, while severe cases result in blades falling off. To prevent pitch bearing cracking during operation, some units have installed reinforcing rings and online crack alarm systems using enameled wire embedded in the reinforcing rings. However, false alarms or delayed alarms still occur, and there is still a risk of cracks expanding and blades falling off. To address these issues, in addition to strengthening standard process maintenance of pitch bearings and bolts and improving component lifespan, it is essential to conduct online condition monitoring of wind turbine pitch bearings and their bolts. This is crucial for accurately detecting fatigue failures in advance and taking timely measures to prevent the problem from escalating. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a wind turbine connecting bolt detection device that utilizes acoustic emission. This solves the problem that some units have installed reinforcing rings in the pitch bearings and online crack alarm systems using enameled wires embedded in the reinforcing rings to prevent cracking of the pitch bearings and failure of the connecting bolts during operation. However, these systems still suffer from false alarms or delayed alarms, and there is still a risk of cracks expanding and blades falling off.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: a wind turbine generator connecting bolt detection device using acoustic emission, comprising a housing, a detection unit disposed inside the housing, a screw attached to the top of the housing, a mounting bracket threadedly connected to the outer wall of the screw, and a magnet installed at the bottom of the mounting bracket.

[0006] Preferably, the interior of the housing is machined with a vacuum cavity.

[0007] Preferably, the upper part of the outer wall of the screw is machined with grinding grooves.

[0008] Preferably, a positioning groove is installed on the top of the housing, and the inner wall of the positioning groove is movably connected to the lower part of the outer wall of the screw.

[0009] Preferably, noise-reducing cotton is installed at the bottom of the housing.

[0010] Beneficial effects

[0011] This invention provides a wind turbine connection bolt detection device that utilizes acoustic emission. The device offers the following advantages: The acoustic emission-based wind turbine connection bolt detection device, through the cooperation of a housing, detection unit, mounting bracket, screw, vacuum chamber, and noise-reducing cotton, utilizes acoustic emission technology to conduct online monitoring of the pitch bearings and connection bolts of wind turbine units. It automatically detects the operating conditions of the pitch bearings and connection bolts, providing early analysis, judgment, and warnings for early fatigue failures. This allows for proactive measures to improve stress in potentially failing pitch bearings (such as grinding and removing rust from bolt holes when internal rust is present) or to adjust or replace bolts. This extends component lifespan and prevents blade fallout. The device also monitors the real-time status of the pitch bearings and automatically assesses their aging and damage levels, assisting maintenance personnel in decision-making. This significantly reduces the workload of frequent tower inspections and minimizes downtime. By using acoustic emission technology to predict and assess the condition of the pitch bearings and connection bolts, it reduces the occurrence of major equipment overhauls and downtime due to unaddressed minor faults, greatly lowering maintenance and equipment repair costs. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] Figure 2 for Figure 1 A sectional view;

[0014] Figure 3 for Figure 2 A schematic diagram of the mounting bracket, screw, and grinding pattern;

[0015] Figure 4 for Figure 2 A schematic diagram of the structure of the inner shell, vacuum chamber, and detection unit.

[0016] In the diagram: 1. Housing, 2. Detection unit, 3. Mounting bracket, 4. Screw, 5. Positioning groove, 6. Grinding texture, 7. Vacuum chamber, 8. Noise-reducing cotton. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Those skilled in the art can connect the components in this case sequentially. The specific connection and operation sequence should refer to the working principle described below. The detailed connection methods are well-known technologies in the field. The working principle and process are mainly described below.

[0019] To prevent pitch bearings from cracking and their connecting bolts from failing during operation, some units have installed reinforcing rings in the pitch bearings and online crack alarm systems using enameled wires embedded in the reinforcing rings. However, there are false alarms or delayed alarms, and there is still a risk of cracks expanding and blades falling off.

[0020] In view of this, this utility model provides a wind turbine connecting bolt detection device using acoustic emission. Through the cooperation of the housing, detection unit, mounting bracket, screw, vacuum chamber and noise reduction cotton, it uses acoustic emission technology to conduct online monitoring of the pitch bearing and connecting bolts of the wind turbine. It automatically detects the operating conditions of the pitch bearing and connecting bolts, analyzes, judges and warns of early fatigue failure of the pitch bearing and bolts in advance, and takes measures to improve the stress of some potentially failing pitch bearings in advance (such as grinding and removing rust from bolt holes when there is rust inside the bolts, eliminating residual rust), or adjusts or replaces the bolts. While extending the life of components, it avoids blade falling off. It monitors the status information of the pitch bearing in real time and automatically judges the aging and damage degree of the pitch bearing, assisting operation and maintenance personnel in decision-making and judgment. It greatly reduces the workload of operation and maintenance personnel to frequently climb the tower for inspection, reduces excessive downtime for inspection, and uses acoustic emission technology to predict and evaluate the status of the pitch bearing and connecting bolts in advance. It reduces the occurrence of major equipment overhauls and downtime due to the failure to repair minor faults in time, and greatly reduces operation and maintenance and equipment maintenance costs.

[0021] Example 1: By Figure 1 , 2As can be seen from points 3 and 4, a wind turbine connecting bolt detection device using acoustic emission includes a housing 1, a detection unit 2 is provided inside the housing 1, a screw 4 is attached to the top of the housing 1, a mounting bracket 3 is threadedly connected to the outer wall of the screw 4, and a magnet 9 is installed at the bottom of the mounting bracket 3.

[0022] In the specific implementation process, it is worth noting that the working principle of the detection unit 2 is as follows: the elastic wave of the acoustic emission source reaches the surface of the material, causing surface displacement. The detector converts the mechanical elastic wave in the material into an electrical signal, which is then amplified, collected and recorded. Based on the observed acoustic emission signal, the position of the acoustic emission source is analyzed and judged, thereby determining the location of the defect.

[0023] Furthermore, a vacuum cavity 7 is machined inside the housing 1;

[0024] In the specific implementation process, it is worth noting that the design of vacuum chamber 7 can minimize the impact of external noise on the wind turbine connection bolt detection device for acoustic emission.

[0025] Furthermore, the upper part of the outer wall of the screw 4 is machined with grinding marks 6;

[0026] In the specific implementation process, it is worth noting that the design of the grinding groove 6 makes it easier for the staff to twist the screw 4.

[0027] Furthermore, a positioning groove 5 is installed on the top of the housing 1, and the inner wall of the positioning groove 5 is movably connected to the lower part of the outer wall of the screw 4.

[0028] In the specific implementation process, it is worth noting that the positioning groove 5 can be used to position and install the housing 1 and the mounting bracket 3;

[0029] Furthermore, noise-reducing cotton 8 is installed at the bottom of the housing 1;

[0030] In the specific implementation process, it is worth noting that the noise reduction cotton 8 can reduce the impact of external noise at the contact edge on the wind turbine connecting bolt detection device for acoustic emission of the application.

[0031] Specifically, when using the acoustic emission wind turbine connection bolt detection device, each blade requires 12 such devices, with a total weight of approximately 1200 grams. Four of these devices are fixed to the inner ring of the bearing using a 40 kgf magnet (9), mounting bracket (3), and screw (4). Four more are fixed to the outer ring of the bearing using the same magnet (9), mounting bracket (3), and screw (4). Four more are adhered to the blade root near the bolt using external structural adhesive (the adhesive structure is not limited and can be chosen according to actual needs; details are omitted here). The three groups of four devices are evenly distributed in a circular pattern at 90-degree intervals. The junction box is connected to the pitch control cabinet for the inner and outer rings of the bearing or the inner ring of the blade root. The installation position of the wind turbine connecting bolt detection device using acoustic emission for the inner ring of the bearing can refer to the installation position of the wind turbine connecting bolt detection device using acoustic emission for the outer ring of the bearing. However, it should not interfere with the operation of the limit switch and the pitch position proximity switch mechanism. The detection of the pitch bearing and bolts of each blade is carried out by 12 wind turbine connecting bolt detection devices using acoustic emission. After local filtering and noise reduction, they are connected to the multi-channel acoustic emission acquisition card in the pitch control cabinet. Then, they are connected to the dedicated signal processing equipment in the nacelle electrical control cabinet through a coaxial cable and slip ring. A wind turbine has three blades, so there are three similar sets of equipment connected to the dedicated signal processing equipment in the nacelle electrical control cabinet. The dedicated equipment converts the electrical signal into an optical signal through a photoelectric conversion device and transmits it through optical fiber to the server in the central control room for signal processing, calculation and analysis.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A wind turbine connecting bolt detection device using acoustic emission, comprising a housing (1), characterized in that: The housing (1) is equipped with a detection unit (2), and a screw (4) is attached to the top of the housing (1). The outer wall of the screw (4) is threadedly connected to a mounting bracket (3), and a magnet (9) is installed at the bottom of the mounting bracket (3).

2. The wind turbine connecting bolt detection device using acoustic emission according to claim 1, characterized in that: The housing (1) has a vacuum cavity (7) machined inside.

3. The wind turbine connecting bolt detection device using acoustic emission according to claim 1, characterized in that: The upper part of the outer wall of the screw (4) is machined with grinding grooves (6).

4. The wind turbine connecting bolt detection device using acoustic emission according to claim 1, characterized in that: The top of the housing (1) is equipped with a positioning groove (5), and the inner wall of the positioning groove (5) is movably connected to the lower part of the outer wall of the screw (4).

5. A wind turbine connecting bolt detection device using acoustic emission according to claim 1, characterized in that: Noise-reducing cotton (8) is installed at the bottom of the housing (1).

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