Fuzzy predictive control system of cryolite ratio for prebake aluminum production cells

In this paper, we designed a fuzzy predictive control system (FPCS) of cryolite ratio for prebake aluminum production cells with the combination of fuzzy logical and predictive models. It includes the sampling, pretreatment of the parameters, the database and fuzzy logical determination, predictive models and correction of the results by feedback etc. The system determines the cryolite ratio by adjusting the aluminum fluoride addition every day. In the first, the system uses the temperature and the historical cryolite ratio to obtain the fuzzy logical decision, and then revises it by the feedback. The control system have been running four months in an aluminum plant West China, and keep the bath ratio stable, current efficiency up to 93.3%, anode and the DC energy consumption to 13300 kWHr per ton Al.