开孔阳极铝电解槽熔体中气液两相流数值模拟

引言目前的电解铝生产工艺以氧化铝为原料,在直流电的作用下,熔融电解质中的氧化铝在高温环境下与碳阳极发生复杂的电化学反应,主要在阳极底掌析出二氧化碳1]。二氧化碳气体从阳极底掌产生到逸出电解质表面的过程中,一方面会不断搅动电解质熔体,阳极气泡与电解质相互发生复杂的传热传质作用,有利于氧化铝颗粒在高温熔体中均匀快速地溶解和扩散运动;另一方面,由于

Numerical simulation of gas-liquid two-phase flow in aluminum reduction cells with perforated anodes

Numerical simulation of anodic bubble/electrolyte two-phase flow in the melts of aluminum reduction cells with the Euler-Euler two-fluid model was conducted based on computational fluid dynamics(CFD).A modified k-εturbulence model was used to describe liquid phase turbulence in the simulation,by assuming the pseudo turbulence resulted from anodic bubbles.The results of CFD simulation for traditional no-hole anodes were compared with the experimental data under similar conditions using particle image velocimetry(PIV).Good agreement was found between the CFD model and PIV measurements,which indicated that the current CFD model could be used to deal with two types of perforated anodes.The electrolyte velocity under perforated anodes could be reduced and the stability of bath flow could be maintained.Perforated anodes could make bath flow more stable.The maximum and average velocity of electrolyte in four-hole anodes were reduced by 9.53% and 12.89%,respectively.The global average bubble fraction in the melts,the local average bubble fraction in anode-cathode distance(ACD)and the thicknesses of bubble layer under the anode with perforated anodes were less than those with no-hole anodes,but the immersion depth of anodic bubbles in electrolyte was almost the same as that in the case of no-hole anodes.Both ACD and cell voltage could be lowered and energy consumption could be reduced.