There are motor power, fan blade angle, fan speed, etc. in electromechanical equipment. If it is a mine fan, the downhole factors include changes in mine resistance, whether the air path has been adjusted, increase the resistance, and the fan will return to reduce the total air volume. But the general impact is not great.

 

After the fan starts to rotate, the airflow behind the fan will generate a speed perpendicular to the motor shaft, that is, the above-mentioned tangential speed C2. This speed is caused by the work done by the fan on the airflow. So what is the shape of the fan blades that are very windy? Let's take a look at it together.

 

This is divided into two parts: one part is to use the power of the motor to oscillate, which will reduce the work of the theoretically usable flange; the other is the wind opportunity to shake the head to obtain the tangential velocity of the air entering the blade machine. The peripheral speed of the large pitch blade machine is higher, and vice versa. When it does not work within its working range, its efficiency is very low, which is reflected in the reduction of the actual output work.

 

Because the fan blades have different circumferential speeds at different radial positions, in order to reduce the radial flow loss under the premise of stable flow, the pitch needs to meet the arctangent relationship. After considering the static pressure, it is necessary to balance the demand for air pressure and volume. If the wind is strong, we need to work at a higher speed. If there is a lot of air, we need to work at a lower speed.