SIMULATION OF ELECTRO-THERMAL PROCESSES IN THE INSTALLATION OF INDUCTION HEAT TREATMENT OF ALUMINUM CASTINGS AND DETERMINATION OF WAYS TO INCREASE ITS EFFICIENCY WHEN PRESSING WIRE ROD FOR POWER CABLES

A computer mathematical model is presented for the study of electrothermal processes in the installation of induction heat treatment of cylindrical aluminum ingots during pressing of wire rod for the manufacture of aluminum wire for power cables. The model makes it possible to determine energetically and technologically appropriate electromagnetic and thermal modes of induction heat treatment of ingots at a given voltage on the inductor. The results of the study of a typical installation for heating aluminum blanks for the purpose of their subsequent gradient pressing using a single-phase single-layer cylindrical inductor made of a rectangular copper tube are presented. Temperature distributions along the length of the aluminum blanks, as well as in the cross-sections of the billets at the output of the inductor, were obtained. A slight difference in the calculated electromagnetic and thermal parameters from the similar parameters of the operating installation confirmed the adequacy of the developed model. Ways to increase the efficiency of the induction heating installation by optimizing the profile of the inductor turns are considered. The influence of the thickness of the wall of the copper tube of the inductor close to the workpiece on the efficiency of the installation was determined and it was shown that its optimal thickness is at the level of the depth of penetration of the electromagnetic field into the metal. The possibility of using a three-phase power supply of the inductor was also investigated and it was shown that in this case it is most appropriate to use a phase angle shift between voltages of 60 el. degree. References 10, tables 2, figures 7.