The Development And Application Of Integrated Energy-saving Technology For The 200kA Aluminium Reduction Cell

In China, aluminum industry is facing tremendous pressure to save energy. Because of overcapacity at home, improving the technics and control technology and developing integrated energy-saving technologies for the operating aluminium reduction cells are the realistic and effective ways to achieve energy-saving target. In this paper, an integrated energy-saving technology for the 200kA cell has been developed and successfully implemented. The main results of this study are as follows:(1) A set of energy-saving technics for the 200kA cell represented as "five low-three narrow-one high" (low temperature, low superheat, low alumina concentration, low cell voltage, low anode effect coefficient, high current density, narrow work region of material balance, narrow work region of heat balance, narrow MHD adjusting region, high anode current density) has been developed, and the simulation shows that the physical fields of the cell are reasonable and reliable on this technical condition.(2) An intelligent multi-loop cooperative control technology was developed, and by calculating the multi-objective (high power efficiency, low power consumption, low emissions, high stability) integrated optimization function, the aim of multi-parameter critical state (include extremely critical distance, critical superheat and critical alumina concentration) dynamic intelligent recognition and intelligent multi-loop (material balance control loop, heat balance control loop and stability control loop) cooperative optimization and control was achieved in electrolytic bath, to ensure the long-term stable operation near the "critical state" in electrolytic cell.(3) Integrated energy-saving technologies (include energy-saving technique and energy-saving control technology) have been implemented successfully in the 200kA series electrolytic cell, with the average cell voltage drop of 3.85V, current efficiency of 93～94% and the DC power consumption down to 12700kWh/t·Al, which resulted in remarkable energy saving effect. At the same time, actual measurement results showed that, with the integrated energy-saving technology, the 200 kA electrolytic cell has regular inner shape, low cell temperature, suitable alumina concentration, balanced cell drop voltage and good production stability.