低能耗下铝电解槽阳极结构的优化

Optimization of anode structure in aluminum reduction cells under low power consumption

为了进一步降低铝电解工业能耗,以仿真软件ANSYS及ANSYS-FLUENT为平台,应用阳极穿孔方式对铝电解用阳极进行结构优化,并进行工业试验,以研究其工业应用并验证仿真结果。计算结果表明:新型阳极下气泡层厚度为1.28 cm,比普通阳极气泡层厚度减少0.72 cm,对应极距电压差约240 mV;阳极表面温度最低为704.3℃,阳极电压降为379 mV,电场分布与普通阳极保持一致;阳极碳块热应力最大值为17.4 MPa,远低于碳块的许用应力。新型阳极在3台槽上进行试验,长期运行的平均槽电压比传统电解槽的降低了229 mV,穿孔阳极结构电解槽电流效率从91.15%提高到91.85%,生产每吨铝直流电耗降低了683 kW.h。仿真结果与实验结果相符,说明此结构阳极能够快速排出气泡进而减小极距。

The perforation in the carbon block to optimize the structure of anode was researched by using simulation software ANSYS and ANSYS-FLUENT in order to reduce the energy consumption of aluminium reduction industry further more. The industrial test was carried out to study the industrial applications and verify the simulation result. The simulation results show that the bubble layer thickness of the perforated anode is 1.28 cm, reduced by 0.72 cm compared with that of the normal anode, the corresponding voltage is about 240 mV. The minimum temperature of anode block is 704.3 ℃, and the voltage drop of the perforated anode is 379 mV and the current density distribution of the perforated anode and ordinary anode are consistent. The maximum of thermal stress is 17.4 MPa in the perforated anode, which is far less than the allowable stress. The perforated anode industrial test was conducted on three cells. The average cell voltage of perforated anodes decreases by 229 mV compared with the traditional reduction cell after long-term operation, and the current efficiency increases from 91.15% to 91.85%. The production per ton aluminium direct current （DC） consumption of perforated anode reduces by 683 kW.h. The experimental results agree with the theoretical calculation, which indicates that the polar distance of the perforated anode is decreased because the bubbles exhaust quickly.