Application of FGI FD5000 High Voltage Frequency Inverter in Ring Air Cooler
1.Overview
The pellet is preferred to extract dry air flow through the drying fan to remove the physical water of the pellet. The pellet is heated to 250℃, and the hot air flow for the blast drying section is the hot exhaust gas from the third cooling section of the ring cooler. Then the hot waste gas of nearly 400℃ after the preheating II is dried, so that the raw ball is dehydrated, dried and heated up, and can withstand the temperature of 650℃ above the preheating I. After the drying section, the hot air flow into the preheating 1 section in the preheating section I above 650℃ continues to dry the pellet through the material layer, and the oxidation begins to ensure that the pellet can withstand the high temperature above 1000℃ in the preheat II section.
2.Implementation plans
In the transformation process of ring air cooler, no. 1 ~4 ring air cooler adopts "one tow one" control and manual bypass cabinet. Frequency conversion control is incorporated into the user's DCS system to achieve remote / local control. In order to facilitate the operation, the field control box is added in the operation room for the control and adjustment of the frequency inverter. The protection setting value of the high voltage start cabinet shall be subject to the protection motor. When the frequency conversion is controlled, the frequency inverter electrically protects the motor, and when the power frequency occurs, the high voltage start cabinet protects the motor.
The transformation plan is as follows: keep the existing high voltage start cabinet, add the high voltage frequency inverter and manual bypass cabinet between the start cabinet and the motor. The start cabinet serves as the start cabinet when the motor power frequency operation, and also the incoming cabinet of the frequency inverter. The manual bypass cabinet is used for switching between frequency conversion and power frequency. In the maintenance of frequency conversion system or failure, the motor is put into the power frequency power grid to ensure that the production is not affected.
3.Application advantage
When the power frequency of the ring cold air machine is running, the power factor is 0.8, the power voltage is 10.05kV, and the power consumption per hour is calculated as 1378.6kW. During the frequency conversion operation of the loop air cooler, the power factor is 0.97, and the input voltage of the frequency conversion is 10.05 kV, and the calculated power consumption per hour is 626.41 kW. When the ring air cooler is running with frequency conversion, the power is saved by 752.19kW per hour. For 300d per year and 24h per day, then the annual power saving: 752.19kW 24h 300 d = 5415,768 million kWh. Thus, the effect of electricity saving is still very obvious.
