Study On Design And Optimization Of The Electric-Magnetic Field Of Large Prebaked Aluminum Reduction Cells

Coupling of the electric field, magnetic field etc in aluminumreduction cells has a significant influence on the current efficiency,energy consumption, and cells' life. It is very important in theoretic andpractical guideline for optimization design, engineering analysis anddevelopment of new cells to understand coupled relation of electric fieldand magnetic field in aluminum reduction cells. In this thesis, with theintegration of latest study, considering all of primary factorscomprehensively, electric and electric-magnetic models with highaccuracy were developed based on the finite element software ANSYS.The emphases were laid on the study of the laws of the electric andmagnetic distribution in large aluminum reduction cells. The mainresearch contents and achievements are as follows:(1) Three-dimensional (3-D) steady models of 350kA prebakedaluminum reduction cells were developed to calculate coupled physicsfields. Effects caused by inside induced current, bus bar system around,the ferromagnetic shell air as well as ledge were taken into account. First,the measured current values in a running cell were applied on the modelas boundary condition to calculate the magnetic field distribution which isvery close to the measured magnetic field distribution in the same cell.Compared with the models built by other researchers, the results of thismodel were more precise and comprehensive. Then, the model was usedto evaluate and optimize the design of magnetic field of this potline.(2) A three-dimensional (3-D) electric field model of 350 kAprebaked aluminum reduction cells was developed for learning andanalyzing the resistance relationship of bus bar system. First, an effectivemethod optimizing the resistance of flexes was obtained, it could helpguiding the design of cathode bus bar. Then, the problems which thecurrent structure of anode beam bus bar brings along were studied andsome suggestion of optimization were put forward. With other factseliminated, the model can give veracious results, therefore, it is stronglyrecommended for design, test and optimization of resistance of bus bar system.(3) A model of large aluminum reduction cells was developed by thesame approach validated by 350kA series cells. From the angle of designof magnetic field, most parts of aluminum reduction cells, including cellbody, shell and bus bar system, were picked out for analysis of themagnetic distribution singly. Then using these traits, several primarydesign of magnetic field were performed and the stability and feasibilityof magnetic field were studied simply. Finally, an effective approach wassummarized for magnetic field design.