阅读说明：本技术 一种安装在风力发电机前部的前置风速管 (Front-mounted wind speed pipe arranged at front part of wind driven generator ) 是由 沈观清 春燕 于 2021-01-20 设计创作，主要内容包括：本发明公开了一种安装在风力发电机前部的前置风速管,涉及风力发电机领域；该安装在风机中心前的前置风速管用于精确测定风机前方来风的风速,提高风机发电效率；该前置风速管是经改进的典型的皮托管；皮托管测量前方来风气流的动压和静压,得到的结果是风速；并将测量到的风速发送给风机机载设备处理,通过处理后得到的精确的风机叶片正确工作角度,用来调整风机叶片正确工作角度,取得最大发电效率。本发明通过安装在风机中心前的前置风速管精确测定风机前方来风的风速和利用测得的风速,大气数据,通过計算中心得到精确风速和风机叶片正确工作角度,调整风机取得最大发电效率,具有突出的实质性特点和显著进步。(The invention discloses a front-mounted wind speed pipe arranged at the front part of a wind driven generator, and relates to the field of wind driven generators; the front air speed pipe arranged in front of the center of the fan is used for accurately measuring the air speed of the incoming air in front of the fan, so that the generating efficiency of the fan is improved; the pre-wind speed tube is a modified typical pitot tube; the pitot tube measures the dynamic pressure and static pressure of the front incoming wind flow, and the obtained result is the wind speed; and the measured wind speed is sent to the fan airborne equipment for processing, and the accurate fan blade correct working angle obtained after processing is used for adjusting the fan blade correct working angle to obtain the maximum power generation efficiency. The invention accurately measures the wind speed of the wind coming in front of the fan through the preposed wind speed pipe arranged in front of the center of the fan, utilizes the measured wind speed and atmospheric data, obtains the accurate wind speed and the correct working angle of the fan blade through the calculation center, and adjusts the fan to obtain the maximum power generation efficiency.)

1. The utility model provides an install leading anemoscope in aerogenerator front portion which characterized in that: the front air speed pipe arranged in front of the center of the fan is used for accurately measuring the air speed of the incoming air in front of the fan, so that the generating efficiency of the fan is improved; the pre-wind speed tube is a modified typical pitot tube; the pitot tube measures the dynamic pressure and static pressure of the front incoming wind flow, and the obtained result is the wind speed; and the measured wind speed is sent to the fan airborne equipment for processing, and the accurate fan blade correct working angle obtained after processing is used for adjusting the fan blade correct working angle to obtain the maximum power generation efficiency.

Technical Field

The invention relates to the field of wind driven generators, in particular to a front-mounted wind speed pipe arranged at the front part of a wind driven generator.

Background

Wind power, photoelectricity and ocean power generation are the three largest energy sources with the lowest cost and endless condition in the future. Due to the limitation of the development speed and range of scientific technology and the technical difficulty of utilizing the three major energy sources, the application and popularization are still in a low-efficiency state for decades.

In recent years, wind power generation is gradually utilized in China, and accounts for more than half of the wind energy utilized in the world. Since wind power generation equipment is expensive, the price of wind power is still high although wind is given free in the earth's natural world.

In order to improve the power generation efficiency of wind power generation, it is very important to accurately measure the wind speed of the wind coming from the wind turbine, accurately and timely adjust the pitch of the blades of the wind turbine, and improve the working efficiency.

The wind speed measurement device of the wind power generation side in the prior art is arranged on a base at the tail part of the wind power generator, and the error of the wind speed measurement device is about 50-80 percent, which cannot be accurate because of the interference of a front propeller and the interference of the base.

Disclosure of Invention

The invention provides a front-mounted wind speed pipe arranged at the front part of a wind driven generator, aiming at improving the wind power generation efficiency and reducing the wind power generation cost by determining the accurate wind speed of the instant wind of each fan.

The invention provides the following technical scheme for solving the technical problems.

The utility model provides a install leading anemoscope in aerogenerator front portion which characterized in that: the front air speed pipe arranged in front of the center of the fan is used for accurately measuring the air speed of the incoming air in front of the fan, so that the generating efficiency of the fan is improved; the pre-wind speed tube is a modified typical pitot tube; the pitot tube measures the dynamic pressure and static pressure of the front incoming wind flow, and the obtained result is the wind speed; and the measured wind speed is sent to the fan airborne equipment for processing, and the accurate fan blade correct working angle obtained after processing is used for adjusting the fan blade correct working angle to obtain the maximum power generation efficiency.

Advantageous effects of the invention

1. According to the invention, the conventional aviation wind speed measuring pitot tube is arranged in front of the center of the fan, so that the accuracy of the measuring result is greatly improved, and the measured wind speed can be directly used for adjusting the working angle of the fan blade.

2. The invention accurately measures the wind speed of the wind coming in front of the fan through the preposed wind speed pipe arranged in front of the center of the fan, utilizes the measured wind speed and atmospheric data, obtains the accurate wind speed and the correct working angle of the fan blade through the calculation center, and adjusts the fan to obtain the maximum power generation efficiency.

Drawings

FIG. 1 is a diagram illustrating the effect of the application of the pre-anemometer according to the present invention;

FIG. 2 is a schematic view of the wind measurement of the preposed anemometer

FIG. 3 is a schematic view of the dimensions of the front wind speed pipe of the present invention;

FIG. 4 is a schematic view of the installation of the pre-anemometer duct of the present invention;

FIG. 5 is a schematic view of an actual wind direction and flow field;

fig. 6 is a schematic diagram of the lift-drag ratio characteristics of the fan blade.

Detailed Description

The invention is further explained below with reference to the drawings:

a front wind speed pipe installed at the front part of a wind power generator, as shown in fig. 1, is characterized in that: the front air speed pipe arranged in front of the center of the fan is used for accurately measuring the air speed of the incoming air in front of the fan, so that the generating efficiency of the fan is improved; the pre-wind speed tube is a modified typical pitot tube; the pitot tube measures the dynamic pressure and static pressure of the front incoming wind flow, and the obtained result is the wind speed; and the measured wind speed is sent to the fan airborne equipment for processing, and the accurate fan blade correct working angle obtained after processing is used for adjusting the fan blade correct working angle to obtain the maximum power generation efficiency.

As shown in fig. 2, the front wind speed pipe comprises an inner pipe, an outer pipe and a dynamic pressure and static pressure measuring device, wherein the front end of the inner pipe is used for measuring the dynamic pressure of the airflow; the small holes on the side surface of the outer pipe are used for measuring the static pressure of the airflow; the inner pipe and the outer pipe are respectively connected with the dynamic pressure measuring equipment and the static pressure measuring equipment, and the result is the current wind speed and is sent to the onboard center of the fan for processing.

1. Front-mounted wind speed pipe

1) Pitot tube for front wind velocity:front of pitot tubeAir was introduced into the end to measure the dynamic pressure. And a small hole is formed in the side surface of the outer pipe for measuring the static pressure. The total effect of the dynamic and static pressures is the total pressure of the local gas flow.

When the pitot tube is fixed and does not rotate or rotates slowly (less than 25 rpm), the dynamic pressure measurement accuracy is accurate with an error of only a few percent. The error can be calculated by adopting an aerodynamic correction method, and can also be corrected by using an actual measurement curve of the designed wind speed pipe.

The static pressure measurement is determined by a small hole on the side wall of the outer pipe, and when the pitot tube rotates at a slow speed, the pneumatic correction can be carried out, and the actual measurement curve can also be used for correcting.

Therefore, the pitot tube which is fixed or rotating can be used for accurately measuring the wind speed and the total pressure of the incoming wind flow.

2) The scale and the measurement precision of the preposed wind speed pipe are as follows:as shown in fig. 3, the low-speed wind flow field is affected by the size and shape of the surrounding objects, and therefore, the determination of the length of the front wind speed pipe is an important factor affecting the accuracy of wind speed determination. The length of A is usually affected by the disturbance of the object in the air flow, and is generally larger than the larger size of L and H, so the length of the preposed air speed pipe is more accurate in measuring the air speed.

Due to the limitation of structural design, the front wind speed pipe is generally 1.1-1.2 times of the maximum size of an object. The length A can be corrected by utilizing a model actual measurement curve of an actual fan under different incoming wind speeds.

The preposed air speed pipe can be made of small-diameter aluminum pipes, carbon fiber composite material pipes, steel pipes and other materials. The measuring equipment can rapidly, immediately and continuously acquire data and can provide wind speed, incoming flow air density, humidity and temperature. The data is processed by a central computer on board the wind turbine to determine the instantaneous operating pitch of the wind turbine blades.

2. Front wind speed pipe and fan efficiency:

1) wind speed and fan operation: the diameter of the modern fan can reach more than 100 meters, and the installation height can reach more than 100 meters. The three-blade paddle is configured with a conventional rotating speed lower than 25 rpm and works safely at a wind speed ranging from 3 m/s to 20 m/s. The power generation efficiency is generally lower than 45%. The pitch of the fan blades can be electrically adjusted, and the wind direction is measured by a tail wind vane. This design has been over 40 years old since the last 70 s of the century into china.

The current material for making fan blades is glass fibre reinforced plastics, the diameter of the blade is from 40 m to 100 m, and the weight of each blade is 6-15 tons. Each fan has a large moment of inertia. Different fans are suitable for different wind speed ranges and are divided into high-speed fans and low-speed fans. The fan blades, the rotation principle and the aerodynamic force are shown in the following figure. It is known that the aerodynamic characteristics of the blades determine the efficiency of the fan. In order to obtain the optimal working pitch of the blades when the current incoming flow is coming, namely the correct angle of the blades corresponding to the incoming flow wind, the accurate wind speed of the current incoming flow wind needs to be known. The principle of accurate wind speed acquisition is shown in fig. 5.

2) Lift-drag ratio characteristic of fan blade

A typical lift-drag ratio/angle of attack curve is shown in fig. 6. In order to drive the fan blades to work well, the blades must always work within-2 ℃ to +8 ℃ with the incoming wind flow, the lift force of the blades with the small attack angles is reduced too much, and the stall of the blades with the too large attack angles causes the resistance to be larger than the lift force. The actual angle of attack of the airflow generated by the direction of the incoming wind and the rotational speed of the blades is always kept within this range,

here, the blade rotation is at a speed along the blade axis of 2 pi rn — the rotational linear speed (r radius, n rotational speed). As long as the wind speed is accurately measured, the actual angle of attack range is determined, and therefore the wind speed measurement accuracy will determine the blade efficiency.

2) Automatic adjustment of fan blade pitch

According to the instant atmospheric data collected by the front-mounted wind speed pipe, the airborne central computer quickly determines the pitch, and the pitch of the blades is adjusted by the executing mechanism, so that high power generation efficiency is obtained. The actuator is an electrically driven servo.

3. Installation of preposed air speed pipe

As shown in fig. 4, fans of different designs have different natural vibration characteristics, and in order to ensure accuracy of measuring wind speed, the vibration characteristics of the fans are determined to design a wind speed pipe structure when the front wind speed pipe is installed. The natural vibration frequency of the wind speed pipe is higher than that of the fan so as to prevent the fan and the front wind speed pipe from being damaged by resonance.

The fan rotates in a vertical plane, and the wind speed in the whole range of the paddle disk is different, so that the fan blades can generate self bending and torsional vibration when rotating, and most of the fan blades can generate periodic vibration. The wind speed pipe is usually made of a small-diameter pipe, the length/diameter is large, vibration is easy to occur, and the measurement precision is influenced, so necessary measures are required in design:

the pipe is made of a light material with high elastic modulus, such as high-strength aluminum alloy or carbon fiber composite material.

And a damping structure with a vibration damping function is adopted during installation.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention; it should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.