Regarding the impact of the change in power grid frequency on the performance of centrifugal air compressors, to be precise, centrifugal air compressors are generally driven by synchronous or asynchronous motors. The change in power grid frequency will affect the change in motor speed, and the change in speed will cause the performance of centrifugal air compressors to change. It can be concluded from both experiments and theories that the flow rate of a centrifugal air compressor is approximately proportional to its speed, the outlet pressure is approximately proportional to the square of the speed, and the power consumed is approximately proportional to the cube of the speed. That is: Q1, Q2--volume flow rate at different speeds; P1, P2--outlet pressure at different speeds; P1, P2--power at different speeds; n1, n2--different speeds.
Therefore, in actual operation, when the power grid frequency is lower than the rated value, so that the speed of the air compressor cannot reach the rated value, the outlet pressure and flow rate of the air compressor will be reduced. If the air separation equipment requires the air compressor wind pressure to be stable, the flow rate of the air compressor needs to be further reduced. At this time, the actual air volume will decrease in a relationship of 2 to 3 with the rotation speed.