Balance chamber pipeline vibration analysis of reciprocating compressor and its countermeasures

When Jimo CNG Filling Station was initially put into production, six D-2.5/(8-16)-250 reciprocating compressors were shut down for revamping because of serious pipeline vibration in their balance chambers. In this paper, analysis is conducted on the causes for pipeline vibration in terms of air pulsation, resonance and mechanical vibration. Pressure pulsation range is determined by measuring the outlet pipeline pressure of Level Ⅰ-Ⅱ and Level Ⅲ-Ⅳ balance chambers. Pressure irregularity of outlet pipeline is also calculated. Based on the properties of natural gas, gas column vibration frequency of balance chamber pipelines is calculated. Resonance tube length range of Stages 1-4 of pipeline systems is determined after gas column resonance is analyzed. Based on the analysis of pipeline structure natural frequency, pipeline vibration of balance chambers is mainly induced by gas column resonance which occurs when natural frequency and excitation frequency are close to each other. The problem is effectively solved by adjusting the length, diameter and configuration of balance chamber outlet pipelines and enlarging the diameter of gas gathering pipelines.