混合污垢在粗糙壁面沉积特性的分子动力学模拟  

Molecular Dynamics Simulation of the Deposition Characteristics of Composite Fouling on Rough Surfaces

作　　者：王景涛[1] 杨佳霖 孙鸿剑 贾玉婷[1] 王兵兵 徐志明[1] WANG Jingtao;YANG Jialin;SUN Hongjian;JIA Yuting;WANG Bingbing;XU Zhiming(School of Energy and Power Engineering,Northeast Electric Power University,Jilin 132012,China)

机构地区：[1]东北电力大学能源与动力工程学院,吉林132012

出　　处：《工程热物理学报》2024年第9期2714-2723,共10页Journal of Engineering Thermophysics

基　　金：吉林省自然科学基金(No.20220101256JC)。

摘　　要：为探究混合污垢在粗糙壁面上的沉积特性,本文以MgO颗粒和碳酸钙溶液组成的混合体系为研究对象,采用分子动力学模拟方法分析了混合污垢在不同粗糙壁面以及运动状态下的沉积机理。结果表明,在静止状态下,混合体系中Ca^(2+)和CO_(3)^(2-)吸附在MgO颗粒表面和壁面上形成碳酸钙团簇,进而MgO颗粒通过碳酸钙团簇间接地吸附在壁面上。通过分析离子与颗粒及壁面之间的相互作用势能表明,壁面粗糙系数越大,吸附的Ca^(2+)和CO_(3)^(2-)的数量越多。在运动状态下,混合污垢沉积过程与静止状态时有类似规律,剪切力的作用会延长混合污垢沉积时间,粗糙度对混合污垢沉积影响显著,MgO颗粒在壁面上沉积不仅与MgO颗粒表面吸附Ca^(2+)和CO_(3)^(2-)点位数量有关,还与碳酸钙团簇与壁面间的连结强度有关,并且Ca^(2+)和CO_(3)^(2-)更容易沉积在壁面粗糙结构的顶端表面和棱角附近。To explore the deposition characteristics of composite fouling on rough surfaces,this study takes the mixed system composed of MgO particle and calcium carbonate solution as the research object.The molecular dynamics simulation method was used to analyze the deposition mechanism of composite fouling on different rough surfaces and under motion states.The results show that in a static state,Ca^(2+)and CO_(3)^(2−)in the mixed system are adsorbed on the surface of MgO particle and the wall to form calcium carbonate clusters,and MgO particle are indirectly adsorbed on the wall through calcium carbonate clusters.The interaction energy between ions and particles with wall surface increases with increasing wall roughness coefficient,and more Ca^(2+)and CO_(3)^(2−)were adsorbed.Under motion conditions,the deposition process of composite fouling exhibits similar patterns as in a static state.The action of shear forces prolongs the deposition time of composite fouling,and the roughness significantly affects the deposition of composite fouling.The deposition of MgO particle on the wall surface is related to the number of adhesion points of Ca^(2+)and CO_(3)^(2−)on the surface of MgO particle and the bond strength between calcium carbonate clusters and the wall.Moreover,Ca^(2+)and CO_(3)^(2−)are more likely to deposit on the top surface and edges near the rough structure of the wall.

关 键 词：分子动力学模拟 粗糙壁面 碳酸钙 混合污垢 沉积 

分 类 号：TK124[动力工程及工程热物理—工程热物理]