(中南大學(xué) 冶金科學(xué)與工程學(xué)院, 長(zhǎng)沙 410083)
摘 要: 使用有限元法建立了300 kA鋁電解槽的焦粒焙燒三維1/4整槽模型，針對(duì)目前普遍采用焦粒均勻鋪設(shè)方式，對(duì)其焦粒焙燒過(guò)程的溫度分布與變化特征進(jìn)行了瞬態(tài)數(shù)值仿真研究。當(dāng)前的焦粒焙燒啟動(dòng)方式存在陰極表面溫差過(guò)大、各陰極炭塊隨空間位置不同溫度分布差異過(guò)大、端部第1至第3塊陰極炭塊平均溫度低于900 ℃、陰極炭塊和搗固糊升溫速度過(guò)快等缺陷。提出在陰極表面從電解槽邊緣向中心依次鋪設(shè)電阻率遞增的焦粒層的優(yōu)化焙燒方案，并進(jìn)行溫度場(chǎng)仿真計(jì)算。結(jié)果表明：該優(yōu)化方案可以使陰極表面溫度分布更加均勻，端部第1至第3塊陰極炭塊表面溫差比優(yōu)化前降低8％以上，中間第４至第１3塊陰極炭塊表面溫差降低30％以上，陰極炭塊和陰極縫糊平均升溫速度降低12％，該優(yōu)化方案更有利于減少電解槽的早期破損。
關(guān)鍵字: 鋁電解；電熱場(chǎng)；焦粒焙燒；仿真；優(yōu)化
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:A three-dimensional transient thermo-electric finite element model of 300 kA quarter aluminum reduction cell was developed to study the thermal field of carbon cathode during the heating-up process by using the same resistivity coke bed. Many defects such as high difference in temperature in the cathode, non-uniform temperature among the cathode surface, non-uniform temperature among the cathodes at different positions, the arerage temperature in the end cathode carbon block 1 to 3 lower than 900 ℃ and too fast heating-up rate during the process were found. In order to solve this problem, an optimization using increasing resistivity coke bed from the side of the cell to the center to preheat the cell was carried out. The results show that the temperature difference is decreased by more than 8% at the end cathode carbon block 1 to 3 and that in the center cathode carbon block 4 to13 more than 30%. The heating-up rate is decreased by 12% in cathodes. The risk of early failure of the cell lining can be reduced by this optimum scheme.
Key words: aluminum reduction; thermo-electric field; coke bed preheating; simulation; optimization
