氯碱工业离子膜电解槽内气液两相流动特性

Gas-Liquid Flow in an Ion-Exchange Membrane Electrolysis Cell from Chlor-Alkali Industry

为验证数值模拟结果的正确性,建立了氯碱工业离子膜电解槽冷模实验装置,对电解槽内液体速度和气含率进行了实验测量,实验数据验证了模拟结果。利用实验和数值模拟方法对不同工况下气含率和气体体积分布进行了研究;对循环板上开口处膜侧瞬时压力进行了监测,分析了该处压力波动特性。结果表明,随着气液流量增大,电解槽内气含率增大,顶部气体滞留层增厚。当电流密度为10 k A×m^(-2)时,槽内气含率达到9.08%,为4.5 k A×m^(-2)时的近3倍。气体体积分数沿电解槽竖直方向逐渐增大,在膜与槽板夹角处最大。循环板上开口处膜侧压力信号波动明显,高频脉动主要由液体流动引起,低频脉动主要由气体流动引起。

Experimental setup of an ion-exchange membrane electrolysis cell from chlor-alkali industry was established to validate simulation results. Liquid velocity and gas holdup in the electrolysis cell were measured and the simulation results were verified. Gas holdup and gas volume fraction distribution in the anode chamber of the electrolysis cell under different operation conditions were investigated experimentally and numerically.The instantaneous pressure signals at the top of the circular plate near the membrane were monitored and analyzed. The results show that gas holdup increases and gas retention layer at the top of the electrolysis cell becomes thicker with the increase of gas and liquid flow rates. The value of gas holdup reaches to 9.08% at current density of 10 kA?m?2, which is nearly three times higher than that at 4.5 kA?m?2. The gas volume fraction increases along the vertical direction of the electrolysis cell and reaches to maximum at membrane corner and channel plate. Pressure signals at the top of the circular plate near the membrane fluctuate obviously.The higher frequency fluctuation of the pressure signals is mainly caused by liquid flow, while the lower ones are caused mainly by gas flow.