摘要
综合考虑动质量传递、电荷守恒以及电极反应动力学,建立锌-镍单液流电池二维瞬态等温模型。与试验数据对比验证模型的准确性,在此基础上研究放电过程中电池内部流场和浓度场的分布和变化规律,进一步考察流速和离子浓度对放电性能的影响。研究结果表明:主流区流速较高,由对流控制传质过程,离子浓度分布均匀;多孔介质域和近壁面流速趋于0,由扩散控制传质过程,离子浓度梯度较大;浓度最大值在出口处的负极表面,需要更多地关注负极表面锌离子的浓度极化。提高锌离子浓度不利于提升电池放电性能,但是提高氢氧根离子浓度对提高放电电压效果明显;提高电解液流速或者改变离子初始浓度都不会影响总的放电时间。
A 2D transient isothermal model of zinc-nickel single flow battery is built by comprehensively considering the dynamic mass transfer,charge conservation and electrode reaction kinetics.The model accuracy is verified by comparing with test data.The distribution and variation of flow field and concentration field inside the battery during the discharge process is studied,and the influence of flow velocity and ion concentration on the discharge performance is investigated.The study result shows:the flow velocity in the main flow area is relatively high,so the mass transfer process is controlled by convection,and the ion concentration distribution is uniform;in porous media area and near wall area,the flow velocity tends to zero,so the mass transfer process is controlled by diffusion,and the ion concentration gradient is large;the maximum concentration appears at the negative electrode surface near the outlet,and so more attention need be paid to the concentration polarization of zinc ions on the negative electrode surface.The zinc ion concentration increasing is not conducive to improving the discharge performance of the battery,but the hydroxide ion concentration increasing is obvious effective on increasing the discharge voltage.Increasing the electrolyte flow rate or changing the initial ion concentration is not affective on the total discharge duration.
作者
姚寿广
赵云辉
赵倩
程杰
YAO Shouguang;ZHAO Yunhui;ZHAO Qian;CHENG Jie(Jiangsu University of Science and Technology,Zhenjiang 212003,Jiangsu,China;Zhangjiagang Smartgrid Fanghua Electrical Energy Storage Research Institute Co.,Ltd.,Zhangjiagang 215600,Jiangsu,China)
出处
《计算机辅助工程》
2018年第5期77-82,共6页
Computer Aided Engineering
基金
国家自然科学基金(51776092)
关键词
锌-镍单液流电池
等温模型
传质
浓度
放电
zinc-nickel single flow battery
isothermal model
mass transfer
concentration
discharge
