耦合电化学和多相流模型的强制循环水电解槽性能研究  

Study on performance of forced circulating water electrolytic cell coupled with electrochemistry and multiphase flow model

作　　者：段旭东 王斯民[1] 文键[2] Xudong DUAN;Simin WANG;Jian WEN(School of Chemical Engineering and Technology,Xi'an Jiaotong University,Xi'an,Shaanxi 710049,China;School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an,Shaanxi 710049,China)

机构地区：[1]西安交通大学化学工程与技术学院,陕西西安710049 [2]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《过程工程学报》2023年第6期880-888,共9页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:22108216)。

摘　　要：碱性电解槽中气泡行为所带来的浓度极化对电解槽的性能影响较大,增大了电解水制氢能耗,但大多数研究未考虑电化学过程中气相产物流动行为的影响。本工作将电化学模型与气液两相流模型耦合,在描述气相体积力的方程中引入了曳力、升力和气泡弥散力,考虑了浓度极化的影响,模拟了强制循环碱性电解槽的产气过程,并进一步研究了操作工况对于电解槽性能的影响。随着电解液温度从60℃升高至80℃,平均电流密度提高了3.84%,电流密度分布均匀度恶化。当电解液入口流速从0.10 m/s增大至0.30 m/s,可以同时提高平均电流密度及其分布均匀度,平均电流密度提高了0.64%。电解液中氢氧化钾浓度对电解性能的影响最大,随着氢氧化钾浓度从2 mol/L提高至6 mol/L,电流密度提高了40.21%,但电流密度分布均匀度会恶化。Hydrogen production from electrolytic water technology is an important way to solve the future energy crisis and realize green development.Among them,alkaline electrolytic water has simple structure and low cost,which is suitable for large-scale development.The concentration polarization caused by the bubble behavior in the alkaline electrolytic cell has a great impact on the performance of the electrolytic cell,reducing the contact area between the electrode and the electrolyte and increasing the resistance and the energy consumption of hydrogen production from electrolytic water.But most of the numerical simulation studies on electrolytic water do not consider the impact of the flow behavior of gas-phase products.In this work,the electrochemical model is coupled with the gas-liquid two-phase flow model,the drag force,lift force and bubble dispersion force are included in the equation describing the gas-phase volume force,and the influence of concentration polarization is considered.The gas production process of the forced circulation alkaline electrolytic cell is simulated,and the calculation results are more in line with the real flow state.The influence of operating conditions on the performance of the electrolytic cell is further studied.It is calculated that with the increase of electrolyte temperature from 60℃to 80℃,the average current density increases by 3.84%,and the uniformity of current density distribution deteriorates.When the electrolyte flow rate is increased from 0.10 m/s to 0.30 m/s,the average current density and distribution uniformity can be improved simultaneously,and the average current density is increased by 0.64%.With the increase of potassium hydroxide concentration from 1 mol/L to 6 mol/L,the current density increases by 40.21%,but the uniformity of current density distribution deteriorates.And among the three operating variables,the electrolytic performance is the most sensitive to the concentration of potassium hydroxide in electrolyte.This work provides guidance for the internal

关 键 词：电解水 氢气 多相流 相间作用力 

分 类 号：TQ116.21[化学工程—无机化工]