Abstract: Aiming at the problem of obstructed drainage existed in axial exhaust fans No.1 and No.2 of 2×600MW unit in Huaneng Tongchuan Power Plant, two reformation schemes of axial exhaust fan drainage pipeline were analyzed. It was considered that connecting the drainage pipe in bottom of impellers stage I and stage II of axial exhaust fan directly into the inlet pipe can solve the problem of obstructed drainage. In Huaneng Tongchuan Power Plant, using the standby unattended time, the drainage pipes of axial exhaust fans No.1 and No.2 were reformed. After the reformation, the problem of obstructed drainage of axial exhaust fan was solved thoroughly, and desired result was obtained.

Key words: axial exhaust fan, obstructed drainage, reformation of drainage pipeline