Abstract: The problem of low lubricating oil pressure interlock shutdown of a centrifugal compressor unit caused by the voltage sag shutdown of oil pump driving motor at the initial stage of trial production of a coal chemical enterprise was analyzed. The results showed that the oil system had some design defects, such as wrong arrangement of accumulator and pressure measuring point, void volume of pump outlet pipeline and no one-way valve at the root of accumulator, which led to the weak anti-fluctuation ability of the oil system. Some solutions such as adding self-starting interlock of oil pump, optimizing the position of standby pump self-starting signal pressure measuring point, lowering the position of vacant pipeline at the outlet of oil pump and installing a one-way valve at the root of accumulator were proposed and implemented, so as to completely solve the problems. The system and component improvement scheme introduced in this paper can provide reference for the oil systems of other compressor units.

Key words: centrifugal compressor unit, oil system, accumulator, void volume