Analyzing and Troubleshooting the Steam-Flow Exciting Vibration Fault for 1 000-MW Unit

The vibration characteristics and mechanisms are studied to address the issue of high-pressure rotor steam-flow exciting vibration which has been occurring frequently in the 1 000-MW steam turbines manufactured by DFSTW. Through the study, it is discovered that the steam excitation force mainly comes from the sealing force, tip clearance exciting force and static steam force. Therefore, corresponding measures such as changing the perspiring direction of inlet steam flows in the seal, improving the stability of bearings and optimizing the sequence of high-pressure valve opening on the spot are put forward for elimination or alleviation of the exciting vibration. At the same time, the actual engineering cases are provided for troubleshooting similar vibration faults.