Study On Multiphysics Of Double-electrode Electroslag Remelting And Energy Saving Mechanism

The two-electrode electroslag furnace is applied to the smelting process of a large-scale electroslag ingot.The electroslag furnace is made up of two consumable electrodes connected in series,and two consumable electrodes are simultaneously in contact with the slag pool to form a loop.The two electrodes were melted at the same time.Compared with the traditional electroslag furnce:Since the cables for the two-electrode electroslag furnace are arranged close to each other and arranged in parallel,the inductive reactance of the short net is reduced under the influence of the mutual inductance effect,and the power factor is improved and the energy consumption is reduced.At the same time,the two-electrode electroslag furnace can improve the temperature distribution in the slag pool,making the shape of the metal bath more flat.The traditional two-electrode electroslag furnace has problems such as uneven temperature distribution and shallow molten pool.This study used AN SYS finite element software to study the multiphysics for the two series-connected electrodes remelting system with diffrent electrode structure and internal rod external tube electroslag remelting system,and the impact on multiphysics for internal rod external tube electroslag remelting system with different structure,different structural parameters and operating parameters.Combining the finite element method and the mathematical calculation method to calculate the remelting rate and thermal efficiency,an effective energy saving scheme is obtained,.The main conclusions of this subject are as follows:(1)The finite element method is used to calculate the electromagnetic field,Joule thermal field and temperature field of two series-connected electrodes remelting system with different electrode structures.It is found that the cylindrical electrode has concentrated magnetic induction intensity,electromagnetic force and Joule heat distribution and the center temperature of the slag pool is the highest due to the concentrated current distribution.The semicircular electrode is the second and the round tube type is the lowest.From the perspective of electromagnetic field,Joule thermal field and temperature field uniformity,the semicircular electrode has the best effect,the round tube electrode is second,and the cylindrical electrode is the worst.(2)The electromagnetic field,Joule thermal field and temperature field of the electroslag remelting system of the inner rod outer tube were calculated by the finite element method.The analysis results show that the current of the inner rod outer tube type electroslag remelting system is concentrated on the surface of the inner rod electrode,and the current of the outer tube is concentrated on the inner surface of the round tube electrode.The current density is decreasing as the depth of the slag pool increased.The maximum current density,maximum magnetic induction maximum electromagnetic force,and maximum Joule heat are concentrated at the center of the top of the slag pool.(3)The the current density of the outer tube is increasing first and then decreasing with the decreased of distance between the inner and outer tubes,the heat distribution of the slag pool is more concentrated,and the maximum Joule heat density increased gradually,but the Joule heat distribution range is decreased.Joules The heat is concentrated more toward the inner rod electrode.As the current frequency decreasing,it can be seen that the current skin effect is significantly reduced.The Joule heating power has no obvious relationship with the current frequency variation.The Joule heat distribution of 100HZ and 25HZ is completely consistent.The Joule heat distribution range is wider and uniform when the current frequency is 50HZ.As the load current increases,the current density increases,and the maximum Joule heat power and the total Joule heat of the slag pool are linear with the load current.(4)The Joule thermal field and temperature field of single-electrode and two seriesconnected electrodes remelting system are calculated based on the finite element method.The calculation results are taken into the calculation formula to obtain the electrode melting rate and therml efficiency.It can be seen from the calculation results that the melting speed of the.two series-connected electrodes remelting system is 2.29 times than that of the ordinary single electrode under the same current load.From the thermal efficiency calculation results,the two series-connected electrodes remelting system is 42.9%.The thermal efficiency is much higher than the single-electrode electroslag remelting system,so the two series-connected electrodes remelting system has the advantages of fast melting speed and good energy saving effect.