阅读说明：本技术 一种风机轮毂中心恒流式热线风速感测系统及方法 (Fan hub center constant-current hot wire wind speed sensing system and method ) 是由 林伟荣 蔡安民 许扬 李媛 于 2021-02-26 设计创作，主要内容包括：本发明公开的一种风机轮毂中心恒流式热线风速感测系统及方法,属于风力发电技术领域。恒流式热线探针固定在整流罩前端面并且露出整流罩前端面表面；恒流式热线探针与探针温度感应器连接,探针温度感应器与温度信号采集器连接,恒流式热线探针和温度信号采集器分别与电流分流器连接,电流分流器分别与恒流电源和信号转化控制器连接,信号转化控制器连接至SCADA系统。本发明的设计合理,总体成本较低,且安装方法较为简易；充分发挥了热线风速仪几何尺寸小、热惯性小、响应频率高、可连续测量、空间分辨率高、对测量流场干扰小等优点,能够准确测量风速,有效避免了风轮转动对风速测量的干扰；同时测得的数据可对传统风速仪进行修正校核。(The invention discloses a fan hub center constant-current hot wire wind speed sensing system and method, and belongs to the technical field of wind power generation. The constant-current hot wire probe is fixed on the front end face of the fairing and exposed out of the surface of the front end face of the fairing; the constant-current hot wire probe is connected with the probe temperature sensor, the probe temperature sensor is connected with the temperature signal collector, the constant-current hot wire probe and the temperature signal collector are respectively connected with the current divider, the current divider is respectively connected with the constant-current power supply and the signal conversion controller, and the signal conversion controller is connected to the SCADA system. The invention has reasonable design, lower overall cost and simpler installation method; the advantages of small geometric size, small thermal inertia, high response frequency, continuous measurement, high spatial resolution, small interference on a measurement flow field and the like of the hot wire anemometer are fully exerted, the wind speed can be accurately measured, and the interference of the rotation of a wind wheel on the wind speed measurement is effectively avoided; meanwhile, the measured data can be used for correcting and checking the traditional anemometer.)

1. A fan hub center constant-current hot wire wind speed sensing system is characterized by comprising a constant-current hot wire probe (5), a probe temperature sensor (10), a temperature signal collector (11), a current shunt (12), a constant current power supply (13) and a signal conversion controller (14);

the constant-current hot wire probe (5) is fixed on the front end surface (4) of the fairing and is exposed out of the surface of the front end surface (4) of the fairing; the constant-current hot wire probe (5) is connected with a probe temperature sensor (10), the probe temperature sensor (10) is connected with a temperature signal collector (11), the constant-current hot wire probe (5) and the temperature signal collector (11) are respectively connected with a current shunt (12), the current shunt (12) is respectively connected with a constant-current power supply (13) and a signal conversion controller (14), and the signal conversion controller (14) is connected to an SCADA system (15).

2. The fan hub central constant current hot wire wind speed sensing system according to claim 1, characterized in that a constant current hot wire probe (5) is fixed at the center of the fairing front end face (4).

3. The fan hub center constant current type hot wire wind speed sensing system according to claim 1, wherein the length of the constant current type hot wire probe (5) exposed out of the surface of the front end face (4) of the fairing is 1-2 cm.

4. The fan hub central constant current hot wire wind speed sensing system according to claim 1, wherein the constant current hot wire probe (5) comprises a hot wire (6), a fork rod (7) and a connecting rod (9); the two fork rods (7) are vertically arranged on the front end surface (4) of the fairing, and the hot wire metal wire (6) is fixedly connected with the two fork rods (7); one fork rod (7) is connected with the current shunt (12) through a connecting rod (9), and the other fork rod is grounded through the connecting rod (9).

5. Fan hub central constant current hot wire wind speed sensing system according to claim 4, characterized in that two forks (7) are symmetrical about the center of the fairing front face (4).

6. Fan hub central constant current hot wire wind speed sensing system according to claim 4, characterized in that two forks (7) are externally wrapped with a protective cover (8).

7. Fan hub central constant current hot wire wind speed sensing system according to claim 6, characterized in that the protective cover (8) is filled with insulating material.

8. The fan hub central constant current hot wire wind speed sensing system according to claim 4, wherein the fork rod (7) and the connecting rod (9) are made of copper.

9. The fan hub center constant current hot wire wind speed sensing system according to claim 1, wherein the ground terminal of the constant current power supply (13) is grounded after passing through the hub, the nacelle and the tower in sequence.

10. The method for measuring the wind speed by adopting the fan hub center constant-current hot-wire wind speed sensing system as claimed in any one of claims 1 to 9 is characterized by comprising the following steps:

the constant current from the constant current power supply (13) is output to the constant current type hot wire probe (5) by the current divider (12), the constant current type hot wire probe (5) generates heat after being electrified, the probe temperature data measured by the probe temperature sensor (10) is processed by the temperature signal collector (11) and then is sent to the temperature signal collector (11), the temperature value of the constant current type hot wire probe (5) is sent to the signal conversion controller (14) by the temperature signal collector (11), and the temperature signal is fed back to the current divider (12) by the signal conversion controller (14) to adjust the numerical value of the constant current; meanwhile, the temperature signal is converted into wind speed data and then sent to the SCADA system (15), so that wind speed measurement and correction and rectification of the anemoscope (16) are realized.

Technical Field

The invention belongs to the technical field of wind power generation, and particularly relates to a fan hub center constant-current hot wire wind speed sensing system and method.

Background

In the present stage, wind speed data of a single wind turbine mainly depends on an anemometer (such as a cup anemometer) installed above a nacelle, and yaw and pitch control is performed by combining wind direction measurement. The accurate measurement of the wind speed is the premise of efficient and stable operation of the wind turbine generator.

However, for wind turbines operating upwind, the wind measuring devices mounted above the nacelle are inevitably affected by the blades of the fan: the rotating blades can generate wake flow, which affects the instant flow field distribution above the nacelle, resulting in deviation between the measurement result of the conventional wind measuring device and the real incoming flow in front of the wind wheel. With the enlargement of the wind turbine generator, the influence of the enlarged blades on the wind speed measurement is also increased, so that the evaluation of the generating capacity of the wind turbine generator and the like are influenced.

Disclosure of Invention

In order to solve the above problems, the present invention aims to provide a system and a method for sensing a central constant-current hot-wire wind speed of a hub of a wind turbine, which have a reasonable structural design, can accurately measure a wind speed, and effectively avoid interference of wind wheel rotation on wind speed measurement.

The invention is realized by the following technical scheme:

the invention discloses a fan hub center constant current type hot wire wind speed sensing system which comprises a constant current type hot wire probe, a probe temperature sensor, a temperature signal collector, a current shunt, a constant current power supply and a signal conversion controller, wherein the constant current type hot wire probe is connected with the probe temperature sensor;

the constant-current hot wire probe is fixed on the front end face of the fairing and exposed out of the surface of the front end face of the fairing; the constant-current hot wire probe is connected with the probe temperature sensor, the probe temperature sensor is connected with the temperature signal collector, the constant-current hot wire probe and the temperature signal collector are respectively connected with the current divider, the current divider is respectively connected with the constant-current power supply and the signal conversion controller, and the signal conversion controller is connected to the SCADA system.

Preferably, the constant-current type heat wire probe is fixed to the center of the cowl front end surface.

Preferably, the length of the constant-current type hot wire probe exposed out of the surface of the front end face of the fairing is 1-2 cm.

Preferably, the constant current type hot wire probe includes a hot wire, a yoke, and a connection bar; the two fork rods are vertically arranged on the front end surface of the fairing, and the hot wire metal wire is fixedly connected with the two fork rods; one fork rod is connected with the current shunt through a connecting rod, and the other fork rod is grounded through the connecting rod.

Further preferably, the two prongs are symmetrical about the centre of the cowl front face.

Further preferably, the two fork rods are externally wrapped with a protective cover.

Further preferably, the protective cover is filled with an insulating material.

Further preferably, the fork rod and the connecting rod are made of copper.

Preferably, the grounding end of the constant current power supply is grounded after sequentially passing through the hub, the nacelle and the tower.

The invention discloses a method for sensing wind speed by adopting the fan hub center constant current type hot wire wind speed sensing system, which comprises the following steps:

the constant current splitter outputs constant current from the constant current power supply to the constant current type hot wire probe, the constant current type hot wire probe generates heat after being electrified, the temperature signal collector processes probe temperature data measured by the probe temperature sensor and then sends the data to the temperature signal collector, the temperature signal collector sends a temperature value of the constant current type hot wire probe to the signal conversion controller, and the signal conversion controller feeds the temperature signal back to the current splitter for adjusting the numerical value of the constant current; meanwhile, the temperature signal is converted into wind speed data and then sent to the SCADA system, so that wind speed measurement and correction and rectification of the anemoscope are realized.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention discloses a fan hub center constant-current type hot wire wind speed sensing system, which utilizes a constant-current type hot wire probe arranged on the front end surface of a fairing, when the wind speed changes, the heat balance temperature of the hot wire probe and the ambient air flow have a corresponding relation, and the incoming wind speed at the installation position (such as the hub center height position) of the hot wire probe can be output only by accurately monitoring the temperature of a hot wire metal wire. The interference of the arrangement position of the constant-current hot wire probe on the front end face of the fairing and the downstream flow field of the blade can be ignored, the operation of the fan is not influenced, and the influence of the heat balance of the constant-current hot wire probe on the relatively slowly rotating hub can be ignored. The system has reasonable structural design, lower overall cost and simpler installation method; the advantages of small geometric size, small thermal inertia, high response frequency, continuous measurement, high spatial resolution, small interference on a measurement flow field and the like of the hot wire anemometer are fully exerted, the wind speed can be accurately measured, and the interference of the rotation of a wind wheel on the wind speed measurement is effectively avoided; meanwhile, the measured data can be input into an SCADA system to correct and check the data of the traditional anemometer, and the method has obvious effects and significance on the aspects of measurement of incoming flow of a fan, updating and support of the existing anemometer system, performance evaluation of the fan and a wind power plant, power generation quantity improvement and the like.

Further, the hot wire probe is arranged at the center of the front end face of the fairing, so that the numerical value is more accurate.

Further, the hot wire is fixed through the fork rod and serves as a connecting lead through the connecting rod, and connection is reliable.

Furthermore, the outside parcel of fork arm has the safety cover, can improve the stability of structure.

Further, the internally filled insulating material can perform a good insulating function.

Furthermore, the fork rod and the connecting rod are made of copper with low resistivity, so that the influence of the heating of a lead wire at a non-heating wire part on the temperature measurement of the heating wire metal wire can be reduced, and the measurement error is further reduced; meanwhile, the mechanical property is good, and the fixation is firm.

Furthermore, the grounding end of the constant current power supply is grounded after sequentially passing through the hub, the engine room and the tower drum, so that the safety and the stability of the system are improved.

The method for measuring the wind speed by adopting the fan hub center constant-current hot wire wind speed sensing system fully exerts the advantages of a hot wire speed measurement technology, and can accurately, real-timely and continuously measure the wind speed data. Because the constant-current hot wire probe is checked, the numerical value is more accurate, and the output data of the anemometer can be corrected by using the data; meanwhile, the balance response between the wind speed and the temperature of the constant-current hot wire probe is quick, high-frequency continuous measurement and output can be realized, and sufficient quantity of the constant-current hot wire probe can be used for data verification of the anemoscope. Therefore, the corresponding relation between the wind speed and the wind speed is obtained, the method can be directly applied to correction and rectification of the output wind speed of the anemometer of the wind turbine generator without the hot wire wind speed measuring device, the performance evaluation and the generated energy prediction of the wind turbine and the wind power plant are achieved, and the method has good application prospect.

Drawings

FIG. 1 is a schematic view of a system of the present invention disposed at a cowl front end face;

fig. 2 is a schematic structural view of a constant current type hot wire probe according to the present invention;

fig. 3 is a circuit diagram of a constant current type hot wire probe according to the present invention.

In the figure: 1-a hub; 2-blade mounting holes; 3-a fairing; 4-the front end surface of the fairing; 5-constant current hot wire probe; 6-hot wire; 7-a fork arm; 8-a protective cover; 9-a connecting rod; 10-probe temperature sensor; 11-a temperature signal collector; 12-a current shunt; 13-constant current source; 14-a signal conversion controller; 15-SCADA system; 16-an anemometer; 17-connecting wires.

Detailed Description

Hot wire wind speed sensing technology (also known as hot wire sensing technology) has significant advantages in measuring fluid velocity over conventional wind measuring devices. The basic principle is that heating current flows through a hot wire metal wire in a hot wire probe, and an accurate corresponding relation of variables such as the hot wire current, the temperature and the wind speed is established based on the energy balance (including self heating, convection heat exchange, radiation heat exchange and the like) of the hot wire metal wire. The heating wire has a constant temperature and a constant current in the working mode, namely the heating current and the temperature of the heating wire probe are respectively kept unchanged. For the constant-current hot-wire anemometer, after calibration, when the wind speed changes, the heat balance temperature of the metal wire and the ambient airflow have a corresponding relation, and the incoming wind speed at the installation position (such as the central height of the hub) of the hot-wire probe can be output only by accurately monitoring the temperature of the hot-wire metal wire.

The invention will now be described in further detail with reference to the following drawings and specific examples, which are intended to be illustrative and not limiting:

referring to fig. 1 and 3, the fan hub center constant current type hot wire wind speed sensing system of the present invention includes a constant current type hot wire probe 5, a probe temperature sensor 10, a temperature signal collector 11, a current splitter 12, a constant current power supply 13, and a signal conversion controller 14;

the constant-current hot wire probe 5 is fixed on the front end face 4 of the fairing and exposed out of the surface of the front end face 4 of the fairing; the constant-current hot wire probe 5 is connected with a probe temperature sensor 10, the probe temperature sensor 10 is connected with a temperature signal collector 11, the constant-current hot wire probe 5 and the temperature signal collector 11 are respectively connected with a current shunt 12, the current shunt 12 is respectively connected with a constant-current power supply 13 and a signal conversion controller 14, and the signal conversion controller 14 is connected to an SCADA system 15.

The constant current power supply 13 is installed inside the hub 1, and the grounding end is grounded after sequentially passing through the hub, the engine room and the tower.

As shown in fig. 2, the constant current type hot wire probe 5 includes a hot wire 6, a yoke 7, and a connection bar 9; two fork rods 7 are vertically arranged on the cowl front end face 4, and the hot wire 6 is fixedly welded to the two fork rods 7, preferably, the two fork rods 7 are symmetrical about the center of the cowl front end face 4. One fork rod 7 is connected with a current shunt 12 through a connecting rod 9, and the other fork rod is grounded through the connecting rod 9. The length of the fork rod 7 is combined with the specific design of the fairing 3 and the like, so that the wind speed of the position where the hot wire metal wire 6 is located is the same as the incoming flow wind speed. The fork rod 7 and the connecting rod 9 are made of copper metal with low resistivity, and the double functions of fixing and conducting are achieved.

The current flowing through the hot wire 6 is supplied and kept constant by the current diverter 12, and the current diverter 12 receives feedback information from the signal conversion controller 14 of the temperature measured by the hot wire probe 6, and optimally distributes the current outputted by the constant current power supply 13 for heating the hot wire 6 so that the current value is in a reasonable range.

And the probe temperature sensor 10 is used for measuring the temperature of the hot wire 6, and the probe temperature sensor 10 is directly connected with the temperature signal collector 11, is used for digitally processing the received temperature signal and sends the temperature signal to the signal conversion controller 14 installed in the hub 1. The signal conversion controller 14 has two functions, namely, converting the received signal into a format which can be received and identified by the SCADA system 15 for storage processing, and feeding back the temperature signal to the current divider 12 at the downstream of the constant current power supply 13 based on the design and check of the constant current type hot wire probe 5, so that the heating current of the hot wire metal wire 6 output by the current divider is in a reasonable range.

In a preferred embodiment of the invention, the constant-current type hot wire probe 5 is fixed in the center of the front end face 4 of the fairing, namely the exposed part of the constant-current type hot wire probe 5 is vertical to the swept surface of the wind wheel, and other accessories and control systems are arranged inside the hub 1 through a connecting lead 17 and in the blade mounting hole 2 on the hub 1. Preferably, the length of the constant current type heat wire probe 5 exposed to the surface of the cowl front end surface 4 is 1 to 2 cm. In one embodiment of the present invention, the constant current type hot wire probe 5 may also be fixed to the tip section of the hub 1.

In a preferred embodiment of the present invention, the two fork rods 7 are externally wrapped with a protective cover 8, and the protective cover 8 is filled with an insulating material.

The method for measuring the wind speed by adopting the fan hub center constant-current hot wire wind speed sensing system comprises the following steps:

the current divider 12 outputs a constant current from the constant current power supply 13 to the constant current type hot wire probe 5, the constant current type hot wire probe 5 generates heat after being electrified, the temperature signal collector 11 processes probe temperature data measured by the probe temperature sensor 10 and then sends the probe temperature data to the temperature signal collector 11, the temperature signal collector 11 sends a temperature value of the constant current type hot wire probe 5 to the signal conversion controller 14, and the signal conversion controller 14 feeds the temperature signal back to the current divider 12 for adjusting a numerical value of the constant current; meanwhile, the temperature signal is converted into wind speed data and then sent to the SCADA system 15, so that wind speed measurement and correction and rectification of the anemoscope 16 are realized.

The SCADA system 15 of the wind turbine receives the wind speed at the center of the hub 1, which is measured and converted based on the temperature of the hot wire 6 and output from the signal conversion controller 14, and also records the measured wind speed of a wind measuring device such as an anemometer 16 disposed above the nacelle. Because the constant-current hot wire probe 5 is checked, the numerical value is more accurate, and the output data of the anemometer can be corrected by using the data; meanwhile, the balance response between the wind speed and the temperature of the constant-current hot wire probe 5 is quick, high-frequency continuous measurement and output can be realized, and sufficient quantity of the constant-current hot wire probe can be used for data verification of the anemoscope. Therefore, the corresponding relation between the wind speed and the wind speed is obtained, and the method can be directly applied to correction and rectification of the output wind speed of the anemometer of the wind turbine generator without the hot wire wind speed measuring device, and can realize the purposes of performance evaluation, power generation amount prediction and the like of the wind turbine and the wind power plant.

It should be noted that the above description is only a part of the embodiments of the present invention, and equivalent changes made to the system described in the present invention are included in the protection scope of the present invention. Persons skilled in the art to which this invention pertains may substitute similar alternatives for the specific embodiments described, all without departing from the scope of the invention as defined by the claims.