Experimental approach for early corrosion detection in pipelines using contact thermometry

ABSTRACT

The goal of this work is to propose a novel non destructive pipeline testing method for corrosion detection using contact thermometry. This method is based on surface temperature measurements of pipe using thermistor probes having an accuracy of ±0.01 K. The thermistor probes could identify the subtle change in surface temperature due to rust when there was uniform heat flux inside the pipe. The coordinates of thermistor probes placed in predetermined locations were used to determine the location of the rust. A methodology was proposed for computer aided detection of rust from this surface temperature measurements. To this end, we established a thermal model using heat transfer equation in a hollow cylinder for the simulation of temperature distribution of pipe. The heat transfer equation was solved by finite element method in polar coordinates. The thermal conductivity of the suspicious region was estimated using the Levenberg Marquardt method for identifying the rust location. Thermal images of the 2D circular cross section of the pipe were generated for further analysis. The concept was validated with simulation results as well as with laboratory experiments. The results show that, regardless of pipe thickness, this method can detect rust in its early stages.

KEYWORDS:

• Contact thermometry
• corrosion detection
• thermistors
• finite element method
• Levenberg–Marquardt method

Disclosure statement

No potential conflict of interest was reported by the author(s).