Jan 21, 2021
Technical requirements for screw air compressor modification inverter
Screw air compressors are widely used in mining, chemical, power, metallurgy, construction, machinery, refrigeration and other industrial sectors, and gradually replace other types of compressors in a wide capacity and industrial and mining scope. Statistics show that the sales volume of screw compressors has accounted for more than 80% of the sales volume of positive displacement compressors. Among all the operating volumetric compressors, 50% are screw compressors. In the future, the market share of screw compressors will continue to expand. In particular, oil-free screw air compressors and various screw process compressors will develop faster.
Ordinary air compressors are transformed into frequency conversion type, which can reduce operating costs and extend the life of machinery. The motors of ordinary air compressors are not allowed to be started frequently, which results in the motors still running at no load when the air consumption is low, which wastes electric energy. Frequent unloading and loading results in frequent changes in the pressure of the entire gas network, which cannot maintain a constant working pressure.
Then after the inverter is modified, the air compressor starts from low frequency, and its starting acceleration time can be adjusted, so as to reduce the impact on the electrical and mechanical components of the compressor when starting, enhance the reliability of the system, and make the compressor use Life extension. In addition, the frequency conversion control can reduce the current fluctuations when the unit starts. This fluctuating current will affect the power consumption of the grid and other equipment. The frequency converter can effectively reduce the peak value of the starting current to a maximum. Compared with the traditionally controlled compressor, the frequency converter controlled compressor has the most practical significance in energy saving, and the compressor working condition supplied according to the demand of air consumption is an economical operation state. Improve the pressure control accuracy, so that the compressor's air pressure output matches the air volume required by the user's air system. The output air volume of the inverter controlled compressor changes with the change of the motor speed, which effectively improves the quality of working conditions.
Change the set power frequency 50HZ no-load operation to variable frequency 30HZ no-load operation to achieve the purpose of energy saving. Then we analyze the energy-saving analysis after the power frequency 50HZ no-load operation is changed to the variable frequency 30HZ no-load operation (frequency converter working mode constant voltage frequency ratio). When the motor changes from power frequency 50HZ no-load operation to variable frequency 30HZ no-load operation, the phase voltage of the stator winding U=U×f is set ÷f=228V, the square of the voltage is proportional to the motor output torque, so the power frequency is 50HZ After the no-load operation is changed to the frequency conversion 20HZ no-load operation, the motor output torque becomes close to 1/3 of the original.