Application of FGI FD300 low voltage frequency inverter in mine main ventilator

1.introduction

The main fan of the coal mine is located at the exit of the air shaft square, which is responsible for the ventilation of the whole system in the coal mine. It requires large air volume, wide adjustment range, and needs 24 hours uninterrupted operation. Its safety status is particularly important, but it is also the main energy consumption equipment in coal mines. The main fan is the most basic part of the coal mine production link, which is responsible for the continuous delivery of fresh air to the mine, dilution and discharge of toxic and harmful gases and dust, regulation of the microclimate in the mine, creating a good working environment, ensuring the safety and health of miners, and improving labor productivity. The required flow rate is large, the adjustment range is wide, and occasionally there are anti-wind requirements, the vast majority of coal mines use anti-rotary axial flow fans as mine main fans.

A coal mine site in Shaanxi province

2.Field demand

(1)High stability requirements: the main fan bears the ventilation task of the entire system in the coal mine, can adjust the microclimate in the mine, create a good working environment, ensure the safety and health of miners, and need 24 hours uninterrupted operation.

(2)High energy consumption: power frequency operation leads to long-term high-intensity operation of the load, which consumes a lot of energy.

3.New scenery solution

The main fan consists of two counter-cyclones, each of which is driven by two motors. Motor parameters are rated voltage 380V, rated power 220kW. Each of the four motors is equipped with a set of FGI FD300 high-performance vector frequency inverter, model FD300-280G/315P-4. The control and feedback signals of the main fan, double-circuit power automatic switching cabinet, frequency inverter, damper and other operation parameter signals required by the process, such as flow rate, wind pressure, gas concentration, harmful gas content, etc., are communicated to the console of the main control room through hard wiring or fieldbus, and the man-machine interface (touch screen) of the main control board realizes real-time monitoring and operation of the operating status.

4.Customer value

  (1)The average opening of the damper before the transformation is 70%-80%. After adding the FD300 frequency frequency inverter, the damper is in 100% fully open state, which can completely eliminate the throttle loss of the damper during adjustment.

 (2)After centralized control, the normal starting time of the main fan is only about 2 minutes, if the vector speed tracking mode is used to start the abnormal rotation, it takes only a few seconds, and the starting current is controlled between 1.5 and 2 times the rated current.

  (3）The use of FD300 frequency inverter improves the power factor of the whole coal mine without adding additional reactive power compensation device.

（4）After FD300 frequency inverter is used, the severe surge phenomenon in the previous throttle adjustment process is avoided.

（5）The use of FD300 frequency inverter reduces the mechanical impact on motor and fan bearings and fan blades, which can significantly improve their service life and reduce maintenance costs.