摘要
铝电解槽中电、热场分布状况直接影响到电解槽的稳定性以及电流效率和能量消耗,而且,在生产实践中,铝电解槽的电、热场分布难以直接测量。因此,对铝电解槽电、热分布的计算机仿真研究有着十分重要的意义。
本文借助大型通用有限元分析软件ANSYS,对铝电解槽电、热场分布进行了研究。首先,分析了铝电解槽结构,针对正常生产情况,给出了铝电解槽电、热场三维静态物理模型及数学模型,并结合铝电解槽的实际情况,给出模型的边界条件。其次,结合160KA铝电解槽进行了铝电解槽电、热场的仿真分析,结果表明:160KA铝电解槽正常生产过程,能量总支出为每秒607.96KW,其中:槽体上部散热量143.48KW、槽体侧部散热量114KW、槽体底部散热量13.8KW、补偿电解所需能量336.68KW;能量总收入为每秒610.24KW,槽总电压为3.814V,其分布为:阳极压降0.36V、阴极压降0.357V、极间压降1.297V、极化压降1.8V。在此基础上,通过相应的参数调整,对350KA铝电解槽电、热场进行了计算,重点给出铝电解槽达到静态能量平衡且各阳极高度相同时,槽内阳极炭块电、热场的分布情况,并对铝电解正常生产中,新换阳极不导电和完全导电时,槽内正常工作的阳极炭块的电、热场分布情况分别做了仿真分析。最后,针对160KA铝电解槽阳极结构尺寸进行了优化设计,给出了两种可行的优化设计方案,两优化方案中,阳极炭块尺寸均增加,钢爪直径、钢爪深度也均增加。其中一方案,阳极炭块长、宽、高依次增加62mm、5mm、55mm,钢爪直径、深度依次增加18mm、13mm;另一方案,阳极炭块长、宽、高依次增加76mm、6mm、11mm,钢爪直径、深度依次增加25mm、18mm。两种优化方案降低槽电压分别为58mV、91mV,电能消耗相应的减少了197.2KWh/t-Al、309.4KWh/t-Al。
The thermal-electric distribution of the aluminum reduction cell has a direct impact on its stability, current efficiency and energy consumption. It is difficult to measure the thermal-electric distribution directly. Therefore, it has great significance to conduct the research by the computer.
This paper studied the thermal-electric field of large prebaked aluminum reduction cell by use of ANSYS. Firstly, the structure about aluminum reduction cell was analyzed, and the 3D physics model and mathematics model for the normal production state were set up. The thermal and electric boundary conditions were given according to the industrial process. Secondly, the paper studied the thermal-electric field distribution of the 160kA aluminum reduction cell. The results showed that the total energy consumption of the 160kA reduction cell is 607.96kW per second, which included the anode heat loss 143.48kW, side heat loss 114kW, bottom heat loss 13.8kW and energy needed for electrolysis 336.68kW; the total energy input into the cell is 610.24kW per second, and the total voltage drop of the cell is 3.814V, which comprises the anode voltage 0.36V, cathode voltage 0.357V, voltage between anode and cathode 1.297V and the chemic reaction voltage 1.8V. The computation of thermo-electric distribution of 350KA cell was also conducted based on the same analysis process as 160KA aluminum reduction cell with changing some structure parameters and other parameters. It strengthens the anode thermal-electric field distribution in the condition of static energy balance and all anodes being the same height, and the thermal-electric field distribution of anode with the conditions that there is no electricity through the new anode and there" is full electricity through the new anode during the normal running of the cell. Thirdly, the anode structure parameters of 160KA aluminum reduction cell were studied and two new designs were made. In the two designs, the anode parameters and stub parameters have been increased. In one design, the length, width and height of the anode was increased respectively by 62mm, 5mm and 55mm, the diameter and the depth of the stub was increased respectively by 18mm and 13mm. In the other design, the length, width and height of the anode was increased respectively by 76mm, 6mm and 11mm, the diameter and the depth of the stub was increased respectively by 25mm and 18mm. The results showed the voltage of the cell was reduced respectively by 58mV and 91mV and energy input into the cell were reduced respectively by 197.2kWh per ton Al and 309.4kWh per ton Al.
引文
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