Mechanical vibration—Evaluation of machines vibration by measurements on rotating shafts—Part 2:Land-based steam turbine-generators in excess of 50 MW with normal operating speeds of 1 500 r/min,1 800 r/min,3 000 r/min and 3 600 r/min
1 Scope
This Part of GB/T 11348 establishes provisions for evaluating the severity of in-situ, broad-band shaft vibration measured radial (i.e. transverse) to the shaft axis at, or close to, the main bearings. These are in terms of:
— Vibration under normal steady-state operating conditions;
— Vibration during other (non-steady-state) conditions when transient changes are taking place, including run up or run down, initial loading and load changes;
— Changes in vibration which can occur during normal steady-state operation.
This Part is applicable to land-based steam turbines and generators with power outputs greater than 50 MW and a normal operating speed of 1 500 r/min, 1 800 r/min, 3 000 r/min or 3 600 r/min. It is also applicable to steam turbines and/or generators which are directly coupled to a gas turbine (such as for combined-cycle applications). In such cases, the criteria of this Part apply only to the steam turbine and the generator (including synchronizing clutches). GB/T 11348.4 and GB/T 6075.4 are applicable to the evaluation of the gas turbine vibration.
The numerical values specified are not intended to serve as the only basis for judging the severity of vibration. For large steam turbines and generators, it is also common to judge the vibration based on measurements taken on non-rotating parts. For such vibration measurement requirements, see GB/T 6075.1 and GB/T 6075.2.
2 Normative References
