Triboelectrification of oil flow in pipelines adjacent to ac power transmission lines

This paper introduces an experimental investigation into the effect of proximity of petrol pipelines to ac power transmission lines on electrostatic charging tendency (ECT) of flowing oil using a reduced-scale model. Simultaneous measurements of the applied ac voltage to the wire, pipe floating potential, corona current and streaming current of the flowing oil are achieved. The results reveal that conductor bundling has a monumental impact on all the measured quantities. In addition, oil temperature causes evident quantitative as well as qualitative changes in the measured streaming current, whereas it has no effect on both pipe floating potential and corona current. The proximity of such pipelines to ac power transmission lines induces higher voltages in the pipelines and hence higher ECT of the flowing oil; especially at high temperature. Consequently, the explosion and fire hazards increase for such pipelines. Electric field computation shows that higher number of subconductors leads to nonlinear increase in both absolute electric field at the ground level and pipe floating potential.