| With the development of the construction of China's high-speed railway,the railway transportation requires higher performance of railway signal and its auxiliary system for both high speed and high security.The railway switch could be closely attached and not function well due to ice or snow in the deep winter.Presently,the ordinary switch snow-melting system performs not well enough with low thermal efficiency,high energy loss,and complex maintenance procedure.Thus a new switch snow-melting system is eagerly needed to improve the performance.In this paper,a moving induction heating snow-melting system was proposed and studied.The surface of the rail is heated via eddy current which obeys the law of electromagnetic induction and exists closely near the rail surface.Therefore the structural performance of the rail is maintained and the influence upon switch rail is eliminated with high heating speed and efficiency compared with the resistance heating snow-melting system.Induction heating principle was applied to undertake a series of numerical simulation of electromagnetic-thermal field for inductive rail-heating.ANSYS,a general finite element software,was employed as a tool for coupling calculation.The mathematic model of the induction heating system was established with the Maxwell equations.Plenty of simulation were performed to compare the new and ordinary snow-melting system.The increase of current density results in the increase of temperature rise rate and the temperature difference between the two side of the rail waist,but slightly variety of the related eddy current penetration depth.While the increase of the current frequency in the coil gives riseto magnetic field intensity,temperature rise rate and the temperature difference,but decreasesthe related eddy current penetration depth and gives a minimum point to the heating time forspecified temperature difference.The influence of the air gap size was also studied in analysis of joule heat,magnetic strength and temperature distribution.Finally,it is analyzed the influence of the gap between coil and rail track on the temperature distribution.And the optimized gap is obtained under certain current density and frequency.In this paper,the electro-thermal properties of the induction system was analyzed via numerical simulation,which paves the way for the control of the input power,heating time,equipment structure and other operating parameters,therefore the heating efficiency is improved with the other heating performances meeting the requirement. |
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