Abstract:

To investigate the influence of current density on transfer characteristics in the electrolysis cell of chlor-alkali industry, the fluid flow, heat and mass transfer of anode chamber at different current densities were simulated numerically using computational fluid dynamics software. The distributions of velocity, temperature and concentration in a grille of the anode chamber were obtained. Taking liquid circulation rate, maximum velocity near the membrane, temperature and concentration at the membrane surface as indices, the performance of the electrolysis cell at different current densities was evaluated. Liquid circulation rate and temperature of membrane surface increased and concentration of brine decreased with increasing current density. Under typical working conditions for current density of 4.5 kA·m^-2, average temperature of the electrolysis cell and of the membrane surface were 86.39℃ and 87.40℃, respectively. Average temperatures of the electrolysis cell and the membrane surface could be maintained at the values of the typical working conditions by lowering inlet temperature of brine when current density increased.

Key words: electrolysis cell, current density, two-phase flow, CFD, numerical simulation

摘要：

为考察电流密度对氯碱工业中离子膜电解槽内流体传递特性的影响,利用流体力学计算软件,对不同电流密度下电解槽阳极室进行了数值模拟,得到了阳极室单个格栅内流体的速度、温度和浓度分布。以液体循环量、膜附近处速度的最大值、膜表面温度和浓度为指标,考察了不同电流密度下电解槽的运行情况。结果表明:随着电流密度的增加,电解槽内液体循环量增大,膜表面温度升高,盐水浓度降低;在电流密度为4.5 kA·m^-2的典型工况下,电解槽内平均温度为86.39℃,膜表面平均温度为87.40℃;当电流密度提高时,可以通过降低进口溶液温度,获得与典型工况相近的电解槽内平均温度和膜表面平均温度。

关键词: 电解槽, 电流密度, 两相流, 计算流体力学, 数值模拟