高密度阳极铝电解槽电-热场耦合仿真研究  

Simulation study of electric-thermal field coupling in high-density anode aluminum electrolyzer

作　　者：魏兴国 廖成志 侯文渊[1,2] 段鹏 李贺松 WEI Xingguo;LIAO Chengzhi;HOU Wenyuan;DUAN Peng;LI Hesong(School of Energy Science and Engineering,Central South University,Changsha 410083,China;School of Energy and Power Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中南大学能源科学与工程学院,湖南长沙410083 [2]中北大学能源与动力工程学院,山西太原030051

出　　处：《中南大学学报（自然科学版）》2023年第2期744-753,共10页Journal of Central South University:Science and Technology

基　　金：国家高技术研究发展项目(2010AA065201);中南大学研究生自主探索创新项目(2021zzts0668)。

摘　　要：在铝电解槽中,阳极炭块内存在的气孔会降低炭块的导电和导热性能,并且增加炭渣,降低电流效率,导致炭耗和直流电耗升高。通过浸渍工艺得到的高密度阳极可以有效地降低炭块的气孔率。为了探究高密度阳极铝电解槽的电-热场变化和影响,基于ANSYS软件建立高密度阳极铝电解槽的电-热场耦合计算模型。研究结果表明:铝电解槽高密度阳极炭块的平均温度上升8.73℃,热应力增加,但形变量减小;侧部槽壳的平均温度下降28.59℃,热应力和形变量均降低,有利于保持槽膛内形稳定;热场变化主要与阳极炭块物性改变有关;槽电压降低49.16 mV,主要与炭块物性改变和电解质电阻率降低有关;高密度阳极电流全导通时间缩短3.39 h,可有效减弱换极产生的负面影响,阳极使用寿命可延长4 d,炭耗降低10.3 kg/t;铝电解槽反应能耗占比增加0.62%,电流效率提高1.69%,直流电耗降低270 kW·h/t。In aluminum electrolytic cells, porosity in anode carbon blocks can reduce the electrical and thermal conductivity of the blocks and increase carbon slag, reduce current efficiency and lead to higher carbon consumption and DC power consumption. High-density anodes obtained by impregnation process can effectively reduce the porosity of carbon blocks. In order to investigate the electric-thermal field variation and the causes of influence in the high-density anode aluminum electrolyzer, a coupled electric-thermal field calculation model of the high-density anode aluminum electrolyzer was established based on ANSYS software. The results show that the average temperature of the anode carbon block increases by 8.73 ℃ when the high-density anode is put on the tank, and the thermal stress increases but the deformation variable decreases. The average temperature of the side shell decreases by 28.59 ℃, and the thermal stress and deformation variable both decrease,which helps to protect the inner shape of the tank chamber stable. The change of the thermal field is mainly related to the change of the physical properties of the anode carbon block. The cell voltage decreases by 49.16 mV which is mainly related to the change of carbon block physical ploperties and the decrease of electrolyte resistivity, respectively. The reduction of 3.39 h in the full conduction time of high-density anode current can effectively reduce the negative effects of electrode change, and the anode service life can be extended by 4 d. The carbon consumption is reduced by 10.3 kg/t. The reaction energy consumption of aluminum electrolyzer is increased by 0.62%, the current efficiency is increased by 1.69%, and the DC power consumption is reduced by 270 kW·h/t.

关 键 词：铝电解槽 高密度阳极 电-热场 耦合仿真 

分 类 号：TF821[冶金工程—有色金属冶金]