An anemometer and wind vane measuring device placed at the front end of a wind turbine nacelle

Abstract

The present invention discloses a wind speed and direction measuring device disposed at the front end of a wind turbine fairing, comprising: an L-shaped horizontal rotating shaft, one end of the horizontal rotating shaft is connected to one end of a first mounting cylinder, the other end of the first mounting cylinder is rotatably connected to a vertical rotating shaft, the vertical rotating shaft is fixed on the upper surface of an airfoil cavity, a fairing is disposed at the other end of the horizontal rotating shaft, and the fairing is rotatably connected to the horizontal rotating shaft; an angle sensor is disposed inside the horizontal rotating shaft; a temperature sensor and a static pressure sensor are mounted on the outer surface of the horizontal rotating shaft; a total pressure tube for measuring total pressure is disposed inside the horizontal rotating shaft; by mounting the measuring device on the fairing at the front end of the wind turbine blade, the undisturbed wind speed in front of the wind turbine can be accurately measured by measuring the total pressure. Additionally, the wind can be accurately aligned and the incoming flow direction can be obtained through a wind direction adjusting device designed based on aerodynamics.

Description

Technical Field

[0001] The invention relates to the field of measurement technology, and in particular to a wind speed and direction measuring device arranged at the front end of a wind turbine fairing. Background Art

[0002] At present, the wind speed and direction measurement used on wind turbines is mainly achieved by installing a contact wind speed and direction measuring device on the nacelle cover behind the blades. This type of device measures the local wind speed and direction and corrects it as the wind speed and direction of the incoming flow. However, since the air flow changes after passing through the wind turbine blades, there is often a large error in the wind speed and direction obtained. Non-contact wind speed and direction measuring equipment can be placed at any position and accurately obtain the wind speed and direction of the incoming flow in front of the wind turbine, but this type of equipment is expensive and is not suitable for large-scale installation in wind farms. The main high-precision contact flow velocity and direction measurement technologies currently include hot wire velocity measurement technology and seven-hole probe velocity measurement technology.

[0003] Hot wire velocity measurement technology is a very mature technology for measuring fluid velocity and direction. It uses a thin metal wire with a heating current placed in the flow field to measure the flow velocity in the flow field. Changes in wind speed will cause the temperature of the metal wire to change, thereby generating an electrical signal to obtain the wind speed. This technology can only obtain the local wind speed at the measurement point, so it is impossible to measure the incoming flow in front of the wind turbine, and this method cannot directly obtain the wind direction of the incoming flow. Pulse hot wire is a hot wire velocity measurement technology that obtains the airflow velocity component by measuring the fluid micro-group passing through two points. Compared with ordinary hot wires, pulse hot wires have the ability to identify the direction of flow velocity. Its working principle is to obtain the instantaneous velocity (U=h / T) by measuring the time it takes for a fluid micro-group to flow through two points. The measurement probe consists of three very thin tungsten wires (several microns). Among them, the front and rear sensing receiving wires of the space velocity probe are parallel to each other, and the middle pulse transmitting wire is perpendicular to the sensing wire; when measuring the velocity, the pulse current passes through the transmitting wire, instantaneously heating the fluid around the wire to form a fluid thermal micro-group, which moves with the local instantaneous velocity and reaches a certain receiving wire, causing the instantaneous resistance of the receiving wire to change, which is converted into a resistance signal through the bridge, and after amplification, filtering, interference suppression and differential processing, the flight time is read by the comparator and sent to the microcomputer for data processing, thereby obtaining the instantaneous velocity component perpendicular to the three wires. The flow direction can be determined by which receiving wire senses the thermal mass.

[0004] The seven-hole probe is a multi-hole probe. By using multi-hole measurement technology and based on the interrelationships of various pressure values, it can obtain three-dimensional velocity information, pressure information, and vorticity information in the flow field. When the interference of contact measurement on the flow field can be ignored, the seven-hole probe is often the first choice for measuring velocity, pressure, etc. In the measurement of the wake flow field of a bluff body, due to the complexity of the flow, the air flow has a large deflection angle. Although the five-hole probe and three-dimensional hot wire can measure the three-dimensional velocity components at local points in the wake flow field, they cannot measure the air flow (relative to the probe axis) with a flow angle greater than 45°. The seven-hole probe can measure the large-deflection flow with an air flow deflection angle of 78°, with a test accuracy of 1%, and can obtain the total pressure and static pressure at a certain point in the spatial flow field.

[0005] For the above two methods of measuring the lateral velocity of air flow, neither can be directly installed on the front hub of the wind turbine to measure the wind speed and direction. The hot wire anemometry can only measure the local wind speed. Since the oncoming flow is affected by the wind turbine, the wind speed near the hot wire anemometer changes greatly compared with the oncoming flow speed after the flow is disturbed, so there is a large error in the measured wind speed. Although the seven-hole probe can calculate the wind speed and direction by measuring the total pressure and based on the local static pressure, due to the rotation of the hub, the original algorithm of the seven-hole probe cannot be used normally, and a new algorithm needs to be developed. In addition, the processing accuracy of the seven-hole probe is very high, and the cost of related pressure measurement equipment is expensive, and it cannot meet the working requirements of the wind turbine wind farm for a long time under relevant environmental conditions. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a wind speed and direction measuring device with low cost and accurate measurement data.

[0007] In order to achieve the above object, the technical solution provided by the present invention is: a wind speed and direction measuring device placed at the front end of the wind turbine fairing, including: an L-shaped horizontal rotating shaft, one end of the horizontal rotating shaft is connected to one end of the first mounting cylinder, the other end of the first mounting cylinder is rotatably connected to a vertical rotating shaft, the vertical rotating shaft is fixed on the upper surface of the airfoil cavity, a fairing is provided at the other end of the horizontal rotating shaft, and the fairing is rotatably connected to the horizontal rotating shaft; an angle sensor is arranged inside the horizontal rotating shaft; a temperature sensor and a static pressure sensor are installed on the outer surface of the horizontal rotating shaft; a total pressure tube for measuring the total pressure is arranged inside the horizontal rotating shaft.

[0008] Preferably, the specific wind speed is calculated by the following formula (1)

[0009]

[0010] In the formula, v is the wind speed, p t is the total pressure, p s is the static pressure, and ρ is the air density.

[0011] Preferably, the air density ρ in formula (1) is calculated by formula (2).

[0012]

[0013] Where ρ is the air density, p s is the static pressure, R is the molar gas constant, and T is the air temperature.

[0014] Preferably, a first bearing is provided between the first mounting cylinder and the vertical rotating shaft, and the first mounting cylinder is rotatably connected to the vertical rotating shaft through the first bearing.

[0015] Preferably, the fairing is fixed on the second mounting cylinder, and the second mounting cylinder is connected to the outer surface of the horizontal rotating shaft through a second bearing.

[0016] Preferably, an angle sensor mounting plate is provided between the first mounting cylinder and the horizontal rotating shaft, and the angle sensor is fixed on the angle sensor mounting plate.

[0017] Preferably, the total pressure pipe is connected to the control cabinet through a hose, and the angle sensor, the temperature sensor, and the static pressure sensor are respectively connected to the control cabinet through cables.

[0018] Preferably, a tail rudder is connected to the airfoil cavity.

[0019] The beneficial effects of the present invention compared with the prior art are as follows: By installing the measuring device on the fairing at the front end of the wind turbine blade, the undisturbed wind speed in front of the wind turbine can be accurately measured by measuring the total pressure. In addition, through the wind direction adjusting device designed based on aerodynamics, the wind can be accurately aligned and the incoming flow wind direction can be obtained. At the same time, the technical cost of the present invention is much lower than that of existing other technologies such as seven-hole probes. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 and Figure 2 are the overall structure diagrams of the present invention;

[0021] Figure 3 is Figure 1 the partial enlarged view at A in

[0022] Figure 4 and Figure 5 are the experimental data diagrams in an embodiment of the present invention;

[0023] In the figure, 1 - horizontal rotation axis; 20 - first bearing; 21 - first mounting cylinder; 30 - second bearing; 31 - second mounting cylinder; 32 - fairing; 4 - vertical rotation axis; 51 - airfoil cavity; 52 - rudder; 61 - angle sensor mounting plate; 62 - angle sensor; 71 - temperature sensor; 72 - static pressure sensor; 73 - total pressure tube; 8 - control cabinet. Detailed implementation manner

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] As shown in this application and the claims, unless the context clearly indicates an exception, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0026] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps described in these embodiments do not limit the scope of this application. At the same time, it should be understood that for the sake of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant field may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0027] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above terms have no special meanings, so it should not be construed as a limitation on the protection scope of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of this description. In addition, it is required to understand this application not only through the actual terms used, but also through the meanings implied by each term.

[0028] Referring to Figures 1 - 3 , this embodiment provides a wind speed and direction measuring device placed at the front end of a wind turbine fairing. The device includes an L-shaped horizontal rotating shaft 1. One end of the horizontal rotating shaft 1 is connected to one end of a first mounting cylinder 21, and the other end is connected to a second mounting cylinder 31 through a second bearing 30. The second mounting cylinder 31 can rotate around the horizontal rotating shaft 1. A fairing 32 is fixedly connected to the second mounting cylinder 31, so that the fairing 32 can follow the second mounting cylinder 31 and rotate around the horizontal rotating shaft 1.

[0029] Furthermore, the other end of the first mounting cylinder 21 is rotatably connected to a vertical rotating shaft 4. The vertical rotating shaft 4 is fixed on the upper surface of an airfoil cavity 51. A tail rudder 52 is connected to the airfoil cavity 51. A first bearing 20 is provided between the first mounting cylinder 21 and the vertical rotating shaft 4, so that the first mounting cylinder 21 can rotate around the vertical rotating shaft 4, and then drive the horizontal rotating shaft 1 to rotate in the horizontal direction.

[0030] Furthermore, an angle sensor mounting plate 61 is provided between the first mounting cylinder 21 and the horizontal rotating shaft 1. An angle sensor 62 is fixed on the angle sensor mounting plate 61. The included angle between the horizontal rotating shaft 1 and the wind direction can be measured through the angle sensor 62.

[0031] In addition, a temperature sensor 71 and a static pressure sensor 72 are installed on the outer surface of the horizontal rotating shaft 1. The temperature sensor 71 is used to measure the air temperature, and the static pressure sensor 72 is used to measure the air static pressure at the current position. A total pressure tube 73 for measuring the current total air pressure is provided inside the horizontal rotating shaft 1. The total pressure tube 72 is connected to the control cabinet through a hose 74. The angle sensor 62, the temperature sensor 71, and the static pressure sensor 72 are respectively connected to the control cabinet 8 through cables.

[0032] By fixing the horizontal rotation axis 1 on the first mounting cylinder 21, and connecting the second mounting cylinder 21 to the vertical rotation axis 4 fixed on the airfoil cavity 51 through bearings, the wind measurement device can be installed at the front end of the wind turbine fairing 32, and the wind measurement device is prevented from moving with the rotation of the wind turbine fairing 32. The tail rudder 52 and the airfoil cavity 51 mainly provide the aerodynamic force and moment for making the wind measurement device face the oncoming flow, and drive the angle sensor 62 in the airfoil cavity through the vertical rotation axis 4 to obtain the relative horizontal angle between the wind direction and the horizontal rotation axis 1. This angle is the relative angle between the oncoming flow and the center line of the wind turbine rotation axis. When this angle is zero, the wind turbine faces the wind, and at this time, the pressure measured by the total pressure tube 73 is the total pressure of the current oncoming flow. The signal and the air temperature signal measured by the current temperature sensor 71 and the air static pressure signal measured by the static pressure sensor 72 are transmitted to the control cabinet 8 through the cable. The controller 8 combines all the data to calculate and obtain the wind speed. The specific wind speed is calculated by the following formula (1)

[0033]

[0034] In the formula, v is the wind speed, p t is the total pressure, p s is the static pressure, and ρ is the air density.

[0035] In addition, the air density ρ in formula (1) is calculated by formula (2)

[0036]

[0037] In the formula, ρ is the air density, p s is the static pressure, R is the molar gas constant, and T is the air temperature.

[0038] To more clearly show the beneficial effects of this embodiment, refer to Figure 4 and Figure 5 , and the above arrangement was used to conduct two ground tests. The wind measurement equipment was supplied with air through the air duct to make it automatically face the wind, and then the oncoming flow wind speed was measured. The calculation results are as Figure 4 and Figure 5 shown. It should be noted that the ordinate in the figure indicates the wind speed, with the unit of m / s, and the abscissa represents the number of times. It can be seen from the figure that the wind alignment error of the wind turbine is less than 1 degree, and the wind speed measurement error is less than 1 m / s. The measurement device provided in this embodiment is installed on the fairing at the front end of the wind turbine blade. By measuring the total pressure, the undisturbed wind speed in front of the wind turbine can be accurately measured. Through the wind direction adjustment device designed based on aerodynamics, accurate wind alignment can be achieved, and the oncoming flow wind direction can be obtained. In addition, the technical cost of the present invention is much lower than that of existing other technologies such as seven-hole probes.

[0039] The above are only embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall similarly be included within the patent protection scope of the present invention.

Claims

1. An anemometer and wind vane measuring device placed at the front end of a wind turbine fairing, characterized in that, Comprising: An L-shaped horizontal rotation shaft, one end of the horizontal rotation shaft is connected to one end of the first mounting cylinder, the other end of the first mounting cylinder is rotatably connected to a vertical rotation shaft, the vertical rotation shaft is fixed on the upper surface of the airfoil cavity, a flow deflector is arranged at the other end of the horizontal rotation shaft, and the flow deflector is rotatably connected to the horizontal rotation shaft; an angle sensor is arranged inside the horizontal rotation shaft; a temperature sensor and a static pressure sensor are installed on the outer surface of the horizontal rotation shaft; a total pressure tube for measuring the total pressure is arranged inside the horizontal rotation shaft; a tail rudder is connected to the airfoil cavity; the tail rudder and the airfoil cavity provide aerodynamic force and moment for making the wind measurement device face the oncoming flow, and drive the angle sensor in the airfoil cavity through the vertical rotation shaft to obtain the relative angle between the wind direction and the horizontal rotation shaft with respect to the horizontal plane, and this angle is the relative angle between the oncoming flow and the center line of the wind turbine shaft. When this angle is zero, the wind turbine faces the wind, and at this time, the pressure measured by the total pressure tube is the total pressure of the current oncoming flow. The signals of the total pressure, the air temperature signal measured by the current temperature sensor, and the air static pressure signal measured by the static pressure sensor are transmitted to the control cabinet through cables, and the controller combines all the data to calculate and obtain the wind speed.

2. The anemometer and wind vane measuring device according to claim 1, characterized in that: The specific wind speed is calculated by the following formula (1) （1） In the formula, is the wind speed, is the total pressure, is the static pressure, is the air density.

3. The anemometer and wind vane measuring device according to claim 2, characterized in that, The air density in formula (1) Calculated from formula (2) （2） In the formula, is the air density, is the static pressure, R is the molar gas constant, and T is the air temperature.

4. The anemometer and wind vane measuring device according to claim 1, characterized in that: A first bearing is arranged between the first mounting cylinder and the vertical rotation shaft, and the first mounting cylinder and the vertical rotation shaft are rotatably connected through the first bearing.

5. The anemometer and wind vane measuring device according to claim 1, characterized in that: The flow deflector is fixed on the second mounting cylinder, and the second mounting cylinder is connected to the outer surface of the horizontal rotation shaft through a second bearing.

6. The anemometer and wind vane measuring device according to claim 1, characterized in that: An angle sensor mounting plate is arranged between the first mounting cylinder and the horizontal rotation shaft, and the angle sensor is fixed on the angle sensor mounting plate.

7. The anemometer and wind vane measuring device according to claim 1, characterized in that: The total pressure tube is connected to the control cabinet through a hose, and the angle sensor, the temperature sensor, and the static pressure sensor are respectively connected to the control cabinet through cables.

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