Commonly used air compressor, especially the piston way to control the pressure of air compressor, reduce the power consumption of air compressor, such as the domestic liuzhou air compressor factory production of piston air compressor, foreign has wang gen air compressor equipment company and Ingersoll orchid company production of screw air compressor, all, with this way.The advantage of this method is that the control method is simple and does not need additional logic control system, so the cost is low.The disadvantage is that the pressure fluctuation range is large, the safety factor is low, often can not unload or unload after not pressurizing phenomenon.
In view of this situation, in 2000, our company decided to change the control of 4 piston loaded valves of the paper machine to the frequency conversion control of the motor, and achieved obvious results.After that, two wang gen air compressors of 2 paper machines were improved in 2002, which also achieved obvious effect.The improved air pressure system not only maintains the stability of pressure, but also greatly saves the power consumption.
Our plan is in the air compressor station system, cancel all air compressor inlet unloading valve, then whether the gasification of air compressor capacity and compressed air consumption situation of factory, has decided to adopt the frequency conversion control air compressor machine is used for such as 01 machine, 1 air compressor for the frequency conversion control, 02 air compressor machine, 2 for the frequency conversion control, other air compressor adopts frequency control;Soft starter is used instead of contactor.No matter is the frequency conversion operation air compressor or power frequency operation system control.In addition, a pressure sensor is added to the total output line to provide a feedback signal to the regulator and form a closed-loop control system.The working frequency of frequency converter is controlled by the output of regulator.When the gap between the actual value and the set value is large, then =10 regulator outputs a larger value, and the fast operation of the variable frequency air compressor may be close to the power frequency, so that the actual pressure value is close to the set value as soon as possible;When the actual pressure value is close to the set value and the changing value of pressure is small, the frequency of the frequency converter gradually decreases until the actual pressure value is approximately equal to the set value, then the frequency of the frequency converter basically reaches a stable and changes with the change of the actual pressure.In addition, no matter the piston type air compressor or screw type air compressor, in order to ensure good lubrication, should set a minimum frequency, otherwise, the air pressure will alarm or damage due to the lubricating oil situation.
First of all, the pressure of the main pipe is very stable. Under normal circumstances, the output pressure is maintained at or below the set value of + 0.0 ° c.Second, frequency conversion air compressor is energy saving, working current of the driven motor by the improvement in front of 125 people now reduced to 0 as the frequency of 50, but often air compressor to run only in 40 hz, the space-time compressor current is only 92 people, according to save 15, 7.5 jia can save electricity per hour, can save electricity 64, 8001 a year. Once again, the improved air compressor, equipment availability and reliability are improved and never appear the equipment failure caused by pressure too low or too, and so on and so forth.Finally, due to a smooth start, the wear of the equipment decreases and the failure rate of the equipment decreases, which greatly reduces the maintenance cost and maintenance intensity of workers.