A Study on Vibration in Generator Exhaust Gas Pipes caused by Acoustic Resonance

Generators are essential power sources on vessels, where efforts to reduce environmental pollution have led to the installation of Selective Catalytic Reduction(SCR) systems to decrease nitrogen oxide (NOx) emissions. However, in response to specific client requirements, some vessels are also equipped with bypass lines that allow exhaust flow to circumvent the SCR system. This configuration has been associated with elevated vibration levels in the exhaust pipes and surrounding structures when the bypass route is engaged. Vibration measurements indicated that acoustic resonance was the primary cause of these increased vibrations. To mitigate this issue, additional devices were installed to reduce vibration levels. This paper presents a case study on the vibration phenomenon caused by acoustic resonance in the generator exhaust gas system and discusses the corrective measures implemented. Through this study, insights are provided into effective approaches for mitigating resonance-induced vibrations in marine exhaust systems, thereby supporting improved structural integrity and operational safety.