| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 774142 | Engineering Failure Analysis | 2013 | 11 Pages |
High vibrations in admission piping of a steam turbine were analyzed. Vibration failure was detected after piping modification as part of upgrading a 300 MW power turbine plant searching for 10% power increment. However, after 1 year operation a vibration malfunction was detected in control valve and fittings of income piping with risk of cracking for maximum output. A study of computational fluid dynamics (CFD) revealed large steam flow instabilities produced by recirculation and high velocity exceeding a critical point. Measurements of natural frequency piping system with the turbine stall and subsequent measurements of frequency and vibration analysis during turbine operation indicated that recirculating flow plays a main role in the vibration problem by resonance. The paper discusses CFD results obtained with a proposed pipe configuration that reduces turbulence effects. Combined pressure slide and diameter increment in piping lead to reduced vibration turbine operation.
► Characteristics of vibration in steam pipes of power turbine income. ► Flow instability may excite pipe natural frequency during engine operation. ► Sliding pressure mode reduced flow induced vibrations during turbine start up. ► CFD analysis detected flow recirculation leading to pipe resonance condition.
