Power frequency screw machine can be frequency conversion in theory, but in fact the installation of frequency converter can not achieve the expected energy-saving effect, but may bring a series of problems.
The analysis is as follows:
limited energy saving effect:
- even if the frequency converter is installed, the adjustment range is limited, usually only 25~50Hz, which basically can not play a significant energy saving effect. The frequency conversion screw machine can save energy because it can adjust the current and speed according to the production situation, so as to match the actual gas demand. After the power frequency screw machine is equipped with a frequency converter, this flexible adjustment cannot be realized due to the design limitations of the motor and the compressor itself.
May damage equipment:
- the motor speed of the power frequency screw machine is constant, and the heat dissipation design is also based on this feature. After installing the frequency converter, the motor speed is reduced, which may lead to a great loss of heat dissipation effect, and then burn the motor.
- The fuel injection quantity of the main machine of the power frequency screw machine is usually fixed and will not be automatically reduced due to the reduction of the speed. Continuous full oil injection may cause serious emulsification when the speed is reduced, causing the system to contain water, damaging the bearings and the main engine, and greatly shortening the service life of equipment components and the whole machine.
Unstable operation:
- after the power frequency screw machine is equipped with a frequency converter, the control system of the frequency converter and the pressure signal sensor of the original air compressor may not be able to achieve a good synchronous matching, resulting in a series of phenomena such as slow signal transmission disorder and random frequency during operation, increasing the equipment failure rate.
Limited scope of application:
- the frequency converter is only suitable for the transformation of a single screw compressor, not for the two-stage compressor. Because the two-stage compressor is driven by a small power motor through large and small gears to drive the overload operation of the two main engines, the frequency conversion transformation is more likely to cause the phenomenon of fever motor, and will greatly reduce the transmission efficiency.
Summary:
although it is theoretically possible to add a frequency converter to make the frequency conversion of the power frequency screw machine, it is not feasible to do so in practice. It can not bring the expected energy saving effect, but may damage the equipment and increase the failure rate. Therefore, if the laboratory or production environment has higher requirements for the energy saving and stability of the air compressor, it is recommended to directly choose the frequency conversion screw machine instead of the frequency conversion transformation of the power frequency screw machine.
