Vibro-acoustic deposit detection in pipelines

Deposits (waxes, hydrates, etc.) change the damping properties of pipelines. The damping ratio of the pipeline increases with increments in deposit thickness. Thus, the evaluation of the damping ratio of the pipeline provides a non-destructive testing of the pipeline deposits. Deposits could be detected by monitoring the vibro-acoustical response of the pipeline while it is subjected to vibration excitation.

Vibro-acoustical pipeline monitoring is a promising technology, but it has been little studied.

A novel vibro-acoustical technology of deposit detection in pipelines is proposed, developed, and validated through numerical simulation. A new generic feature representation approach is used in this technology. Analytical expressions of the proposed diagnostic features, one- and two-dimensional probability density functions of the features, and likelihood ratio of the features are obtained for the first time for random sinusoidal vibration excitation.

Comparison of the proposed technology with the traditional technology based on the power spectral density is undertaken using numerical simulation (by the Simulink package) and Monte Carlo procedure. It is shown that the proposed technology provides an essential diagnostic effectiveness gain vs. that of the technology based on the power spectral density.

Thus, the proposed technology significantly improves the accuracy of vibro-acoustical deposit detection in pipelines.