Study on the melting characteristics of icing on overhead contact lines using high-power fiber laser

The issue of icing on overhead contact lines (OCLs) seriously affects the safety and efficiency of railway transportation, and existing de-icing methods fail to meet the needs of electrified railways. In this paper, a high-power continuous fiber laser is used to conduct numerical simulations and melting ice experiments on OCLs ice-covered samples. The melting characteristics of ice layer are studied under different laser powers, scanning speeds, and laser beam focal positions. The results show that laser energy with a wavelength of 1.08 μm can penetrate the ice layer and generate a larger influence area in the direction of laser irradiation. As the laser power increases from 3 kW to 6 kW, the melting depth, top and bottom melting width grow from 4.1 mm, 0.9 mm, and 0.1 mm to 5.8 mm, 1.6 mm, and 0.2 mm (gains of 41.5 %, 77.8 %, and 100 %). At 6 kW, the melting behavior achieves maximum melting and heat transfer efficiency of 313.2 mm³/s and 14.6 %, and a minimum energy consumption of 19.2 J/mm³. Lowering the scanning speed from 60 mm/s to 15 mm/s increases the melting depth from 5.8 mm to 19.9 mm (a gain of 243.1 %), the top melting width from 1.6 mm to 3.1 mm (a gain of 93.8 %), and the bottom width from 0.2 mm to 0.6 mm (a gain of 200 %). There are maximum melting and heat transfer efficiencies of 552.2 mm³/s and 25.8 % at 15 mm/s, and minimum melting energy consumption of 10.9 J/mm³. The optimal focal position (Z = 20 mm) yields a melting depth of 7 mm, top and bottom melting widths of 2.5 mm and 0.5 mm, respectively, with the highest melting efficiency of 630 mm³/s, heat transfer efficiency of 29.4 %, and the lowest energy consumption of 9.5 J/mm³. The laser-based de-icing method proposed in this paper provides an efficient and feasible new strategy for OCLs de-icing.