Analysis of Vibration Causes in Main Steam Drainage Pipeline on Turbine Side of a Power Plant

Abstract Excessive vibration was observed in the main steam drainage pipeline on the turbine side of a power plant. Through inspections of the pipeline support system and vibration monitoring at selected measurement points, this paper investigates the root causes and proposes mitigation measures. The analysis reveals that the vibration amplitude of the drainage pipeline in Unit #1 is significantly higher than that in Unit #2, primarily attributed to the longer spring hanger rods, insufficient positional restraints, and excessive pipeline length, which collectively reduce the structural stiffness and increase flexibility of the drainage system. To suppress vibrations, a combined approach is recommended: enhancing system stiffness (e.g., optimizing hanger configurations) and installing viscoelastic dampers to dissipate vibration energy.