Frequency Response Diagram for Pipeline Leak Detection: Comparing the Odd and Even Harmonics

Abstract

Pipeline leak detection using hydraulic transient analysis is a relatively new detection technique. For single pipeline systems, recent work has led to two different approaches for determining leak parameters based on leak-induced patterns displayed in a pipeline's frequency response diagram (FRD). The major difference between the two techniques is that one uses the leak-induced pattern within the odd harmonics of an FRD, while the other one uses the leak-induced pattern at the even harmonics. In order to compare and contrast the two approaches, the current research analyses the relationship between the characteristics of the leak-induced patterns and the parameters of the pipeline system. A dimensionless analysis, based on hydraulic impedance, is adopted to simplify the equations. The amplitudes of leak-induced patterns at both the odd and the even harmonics in the FRD are found to be dependent on a critical parameter: the dimensionless steady-state valve impedance, Z and the amplitude of either leak-induced pattern. Finally, the two existing FRD-based leak detection methods are compared, and the approach using the odd harmonics is found to be superior.

Experimental verification of pipeline frequency response extraction and leak detection using the inverse repeat signal

“…In the last decade, the analysis of the FRF of pipeline systems under linear system theory has also been used in integrity monitoring of water pipelines, such as the detection of leaks (Covas, Ramos, & de Almeida, 2005;Duan, Lee, Ghidaoui, & Tung, 2011;, 2014Lee, Vítkovský, Lambert, Simpson, & Liggett, 2005a, 2005bMpesha, Gassman, & Chaudhry, 2001;, discrete blockages (Lee, Vítkovský, Lambert, Simpson, & Liggett, 2008;Sattar, Chaudhry, & Kassem, 2008), extended blockages (Duan, Lee, Ghidaoui, & Tung, 2012, 2013, and general parameter identification (Zecchin, White, Lambert, & Simpson, 2013).…”

Simulation of the Transient Characteristics of Water Pipeline Leakage with Different Bending Angles

“…The secondary pressure resonance peak appeared in the frequency plot with leakage and was larger than the amplitude of the main pressure amplitude without leakage. Gong et al [11,12] determined the location and size of the leak based on the frequency response and analyzed the effects on leakage detection of the odd and even signals of the frequency response map. Kim [13] deduced the frequency domain response function based on the impedance method and analyzed the influences of parameters such as leakage, friction coefficient, wave velocity, pipe length, and valve closing time.…”

Transient Frequency Responses for Pressurized Water Pipelines Containing Blockages with Linearly Varying Diameters

“…Moreover, the complexity of system connections (such as multiple-pipe systems) may cause technical trouble for separating the transient response information (e.g., reflection) of faults from other sources when using this timedomain method. To address this problem, a number of publications proposed spectral analysis as an alternative way for detecting and sizing different localized faults in the frequency domain (Brunone and Ferrante 2004;Ferrante and Brunone 2003;Gong et al 2014;Kim 2017;Lee et al 2006Lee et al , 2008Lee et al , 2015Wang et al 2005).…”