The monitoring of mine wind speed is an important factor to ensure safe production in mines. The working conditions of mines are special and the working environment is complex. Wind speed measurement is an important content in mine safety. The real-time display of the wind speed and air volume of the roadway is an important instrument for measuring the safety parameters of mine ventilation.
With the development of new energy saving and environmental protection, anemometers and wind speed instruments are used more and more frequently. As a typical sensor, wind speed sensor is mainly a device that converts the air flow speed variable into an output signal with a certain corresponding relationship. It is widely used in all mine ventilation general return airway, air outlet, underground main air measuring station, fan wellhead, tunneling face, coal mining face, etc., and corresponding mining enterprises.
In wind speed measurement, ultrasonic anemometers are more accurate. This is a low-cost, high-precision, high-stability wind speed sensor. The system can provide real-time and accurate data of downhole wind speed and air volume, and can be set remotely. The diverse output interfaces are convenient for the connection of sensors and base stations. Its principle is to use an ultrasonic rotary transducer to obtain the wind speed.
The speed of sound in the air is superimposed on the speed of the airflow in the wind direction. If the ultrasonic wave travels in the same direction as the wind, its speed will increase. Conversely, if the ultrasonic wave propagates in the opposite direction to the wind, its speed will slow down. Therefore, under the fixed detection conditions, the propagation speed of ultrasonic waves in the air can correspond to the wind speed function. The precise wind speed and direction can be obtained by calculation. Since a sound wave travels through the air, its speed is greatly affected by temperature. The anemometer detects two opposite directions on the two channels, so the temperature has a negligible effect on the speed of the sound waves.
Since there are no mechanical rotating parts, there are no problems such as mechanical wear, blockage, freezing, etc., and there is no “mechanical inertia”, which can capture the instantaneous wind speed change, not only can measure the conventional wind speed (average wind speed), but also can be measured in any direction. The wind speed component, especially the high-frequency pulsation component in the wind speed can be measured.
Ultrasonic wind speed sensors bring people not only data in many places, but also a safety guarantee. The requirements for downhole equipment can accurately and timely transmit downhole data. However, the traditional methods for the measurement of wind speed and air volume have inaccuracy. High, cost is too high, poor stability and other issues. The emergence of ultrasonic anemometers not only facilitates us to accurately collect data, but also ensures the safety of personnel and property.