| In the smelting process of non-ferrous metals,the stirring of the melt is one of the most important processes in the process.Different from traditional stirring technology,Electromagnetic Stirring technology(EMS)plays a very important role in improving the quality of non-ferrous metal casting,improving the internal microstructure of metal,and improving the performance of non-ferrous metal materials.The traditional EMS equipment has the problems of high power,high inductance,high heat load,low efficiency,low power factor,and low service life.In order to solve these problems,improve the EMS efficiency of non-ferrous metals and reduce the energy consumption of the system.Based on the previous research results,this paper designed a DC EMS device for non-ferrous metal melts,and used ANSYS finite element software to carry out numerical simulation analysis of the electromagnetic field and flow field.The main contents are as follows:1.The operation principle of EMS is studied.For the existing EMS device,the excitation method was selected,and the structure distribution design was selected by DC EMS,and the structural parameters and rated control parameters were obtained.2.DC motor speed control is studied.According to the characteristics of the traditional EMS load motor rotating at a constant speed,in the design of EMS rotating motor control,the armature voltage speed control was selected as the design scheme of the DC PWM type speed control system.Combined with the bridge control circuit,a chaos motor speed control system based on time-delay feedback is designed,and then Matlab is used to simulate and analyze the designed speed control system.3.The electromagnetic field distribution is studied.According to the MAXWELL equations,the APDL module is used in ANSYS to simulate the electromagnetic field.The steady-state electromagnetic field distribution,transient electromagnetic field distribution and electromagnetic torque distribution are analyzed.4.The distribution of the flow field is studied.According to the flow field flow equation and chaotic mixing theory,the Gambit model of the non-ferrous metal flow field in the stirred tank was established.The Fluent software was used to numerically simulate the velocity of the streamline,the distribution of the instantaneous streamline,and the volume fraction distribution of the Si element5.Chaos mixing theory was studied.The Matlab software was used to calculate and analyze the Lyapunov exponent and Kolmogorov entropy of the metal melt flow field to evaluate the melt flow effect.6.The metallurgical effect of DC EMS is studied.Starting from the material analysis subject method,the aluminum-silicon alloy molten slab samples were cut,ground and polished,and chemically corroded.XRD scanning and metallographic microscope were used to obtain the crystal distribution and change trend. |
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