Research And Application On Real-time Monitoring Technology Of The Freeze Profile Of The Aluminum Reduction Cell

Aluminum industry has been paying great attention to the freeze profile in cells. For the long term production practice and theoretical research of the aluminum electrolysis have shown that the freeze profile in a cell has a significant influence on the current distribution, molten electrolyte dynamic properties, current efficiency, energy consumption and the cell life. However it's difficult to measure the freeze profile directly, so finding a new way to monitor the freeze profile continuously is of great importance.With a 230kA prebaked aluminum reduction cell as a test cell, an on-line simulation of the freeze profile has been made based upon the research on the thermo-electric field of the aluminum cell. First a quasi-3D thermo-electric model was set up by using finite volume method and a set of software was successfully developed in Fortran and Visual Basic languages. Then the conditional cell was analyzed by numerical simulation based on the information provided by on-line temperature inspecting system of the aluminum cell shell and the model and software was validated by the results of the measurement.The main achievements and conclusions are as follow.1) The electric-thermal field of the cell can be analyzed accurately using the quasi-3D thermo-electric model and the analytical results agree with the measurement results well. The freeze profile width error is less than 2 cm.2) The software was successfully developed through an organic combination of Fortran and Visual Basic languages which were encouraged to make full use of their advantages. This is also an effective way to develop other engineering application software for calculation.3) The software having friendly interfaces is easy to operate and can on-line monitor the freeze profile of the cell. Also it has high modularization, high independence and convenient maintenance. Industrial tests have proved it stable and reliable.4) The software can provide the supervision and decision support data for the aluminum cell status diagnosing expert system.