Gas compressor

Abstract

In order to reduce operation in a rotation-prohibited frequency range and to prevent resonance in a gas compressor wherein inverter control is performed, this gas compressor has: a compressor main body that compresses a gas; a motor that rotationally drives the compressor main body; an inverter that changes the rotational speed of the motor; a check valve arranged downstream from the compressor main body; a pressure detection means that detects load-side pressure downstream from the check valve; and a control device that, in accordance with the pressure detected by the pressure detection means, controls the frequency output by the inverter. The control device performs a control whereby compressed gas having a prescribed pressure is generated / maintained by increasing / decreasing the frequency, and when the frequency that generates the compressed gas having the prescribed pressure includes a specific frequency, the inverter's output frequency is increased or decreased when the pressure detected by the pressure detection means reaches a pressure corresponding to a frequency that has a more constant pressure width than the prescribed pressure and does not include the specific frequency.

Description

technical field [0001] The invention relates to a gas compressor, in particular to a gas compressor controlled by a variable speed frequency converter. Background technique [0002] In addition to the main body of the compressor, the compressor also includes multiple components such as a motor or a heat exchanger. Therefore, from the viewpoint of vibration, the compressor has various vibration modes and corresponding natural frequencies. For example, in the variable capacity compressor capable of continuously changing the rotational speed disclosed in Patent Document 1, the rotational speed changes, so the rotational frequency of the rotor or its multiple can take countless values. Therefore, at any rotational speed, there is no small possibility of resonating at a natural frequency determined by the structure. Even if the frequency band of the natural frequency is changed by changing the rigidity of the structure or changing the mass of the components, etc., only the frequ...

AI Technical Summary

Problems solved by technology

Even if the frequency band of the natural vibration frequency is changed by changing the rigidity of the structure or changing the mass of the components, it is only limited to the frequency of resonance, and it is difficult to completely avoid the occurrence of resonance

In addition, resonance is a phenomenon that must be avoided, because resonance not only makes vibration, noise violent, but also causes fatigue to be accelerated due to excessive force applied to the resonating part

Images