Abstract: Steam turbine is the key equipment which is most prone to fouling in FCC unit. During the operation of the steam turbine in the 1.2 Mt/a FCC of CNOOC Huizhou Petrochemical Co., Ltd., the pressure of the wheel chamber rises; the steam consumption increases; the speed regulating valve fully opens and the rotation speed decreases, which are judged to be the result of fouling of the flow parts of the steam turbine. The steam temperature of the turbine inlet is reduced and online high-speed cleaning of the turbine is implemented under the condition that the turbine unit is not shut down, the gas compressor torch does not need to be discharged, and the unit is in normal production at low load. After the on-line cleaning, the turbine wheel chamber pressure dropped from 3.4 MPa to 2.1 MPa, steam consumption dropped from 46 t/h to 40 t/h, and the speed regulation valve opening fell from 100% to 60%, which indicates that the online scale cleaning has achieved good results.

Key words: steam turbine, fouling, high-speed, on-line cleaning