Electrical Heating System for Oil Pipelines

Oil production is carried out in different regions of the world, including the Arctic and places with low temperatures in winter. Delivery of oil from an oil well to a terminal or storage site is carried out through pipes, for which heating cables are used in winter. If the temperature of the oil in the pipeline drops, its viscosity can increase greatly, so that pumping through pipes becomes impossible. This means the need for the continuous heating along the entire length of the pipeline, the length of which can reach a kilometer or more. Currently used cables with high resistivity metal conductors can stabilize the heating level by their temperature dependence. However, in some cases, this does not provide flexibility in controlling both the heating level and power consumption. This article discusses an innovative heating system for a pipeline with oil, which does not have the indicated drawback. To heat the cable, the skin effect is used in the conductors with current, which makes it possible to regulate the heat release by changing the frequency at the output of a cycloconverter, and use cheap iron alloys as cable conductors. In high power heating systems, a cycloconverter can improve the compatibility with the mains supply by consuming a sinusoidal current that does not have distortion.