Naslov
DYNAMIC DC INTERFERENCES ON PIPELINES DETECTED BY SIMULTANEOUS MULTIPARAMETRIC FIELD MEASUREMENTS, FREQUENCY PLOTS AND CROSS WAVELET ANALYSIS

Autori
Martinez, Sanja ; Mujezinović, Adnan ; Muharemović, Alija ; Kekez, Krešimir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Eurocorr 2018 Proceedings / - Krakov, 2018, 1-1

Skup
Eurocorr 2018

Mjesto i datum
Kraków, Poljska, 09.09.2018. - 13.09.2018

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
corrosion ; DC interferences ; stray current

Sažetak
Evaluation of DC stray current corrosion likelihood is particularly challenging in urban areas due to the multiplicity of possible stray current sources and the complexity of buried infrastructure. This paper shows advantages of data visualisation trough frequency plots and cross wavelet analysis applied to measurements obtained by simultaneous sampling of: pipe-to- soil potential, transversal potential gradient, probe current and pipeline current using the Stray Current Mapper (SCM) device. Measurements were done at two locations experiencing tramway induced dynamic DC interferences, in the first case, on pipeline under cathodic protection and in the second case, on pipeline without cathodic protection. The traction system generates stray currents, the magnitude and direction of which depend on the location of the load and the horsepower being expended, resulting in seemingly stochastic measurement behaviour. However, frequency plots of the measured quantities give clear visual representation of the time that pipeline spends in a certain state related to the possible harmful effect of stray current and also show the degree of cathodic protection beneficial effect. At both locations, the three cross correlation wavelet plots for each of the quantities: potential gradient, probe current and pipeline current v.s. pipe-to-soil potential show 5% statistical significance levels in periods between 16 and 128 seconds. Time spans and period lengths of observed correlations on all three plots are corresponding. Also, in comparison to SCM measurements, based on the time positions and magnitude of statistically significant periods of correlation, it can be concluded that they are due to the tram passing near the locations where the measurements were made. Statistically significant levels of correlation observed for longer time periods were found to be due to existence of the cathodic protection system, form comparison of measurements at sites with and without cathodic protection. Data analysis and visualisation presented, is aimed at developing reliable method for estimation of harmful dynamic DC stray current effect and cahodic protection beneficial action in complex urban infrastructure environment.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo, Temeljne tehničke znanosti

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