海水换热器析晶污垢物相分析及动力学研究  

Phase Analysis and Kinetic Study of Crystallization Fouling in Seawater Heat Exchanger

作　　者：杨大章 谢晶[1] 柳建华[2] 王金锋 YANG Da-zhang;XIE Jing;LIU Jian-hua;WANG Jin-feng(College of Food Science ＆ Technology,Shanghai Ocean University,Shanghai,China,Post Code ： 201306;School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai,China,Post Code： 200093;Quality Supervision,Inspection and Testing Center for Cold Storage and Refrigeration Equipment,Ministry of Agricuhure,Shanghai,China,Post Code ：201306)

机构地区：[1]上海海洋大学食品学院,上海201306 [2]上海理工大学能源与动力工程学院,上海200093 [3]农业部冷库及制冷设备质量监督检验测试中心,上海201306

出　　处：《热能动力工程》2018年第9期1-6,共6页Journal of Engineering for Thermal Energy and Power

基　　金：上海市教育委员会和上海市教育发展基金会“晨光计划”资助(16CG55);上海海洋大学博士科研启动基金(A2-0203-17-100317);上海海洋大学科技发展专项基金(A2-0203-17-100207)~~

摘　　要：海水换热器常用于沿海能源和化工领域的海水直流冷却系统和循环冷却系统。海水在热交换的过程中容易产生析晶结垢,造成换热效率下降和管路堵塞,这些污垢的组成及结垢机理是目前研究热点之一。本研究搭建一套海水结垢的可视化实验装置,对海水在换热过程中形成的析晶污垢进行了物相分析和动力学研究。通过X射线衍射（X-ray Diffraction,XRD）、扫描电镜（Scanning Electron Microscope,SEM）和X射线能谱（Energy Dispersive X-Ray,EDX）分析海水换热器析晶污垢的元素组成和晶体结构,结果显示污垢的元素组成和晶体结构与水合氢氧化镁铝（Mg6Al2（OH）（18）·4.5H2O）十分相似。基于Kern-Seaton模型,建立适用于海水析晶污垢的动力学模型,并根据实验结果对结垢过程的动力学参数进行拟合。结果表明：在不锈钢表面海水析晶结垢的表观活化能为1.54×104J/mol,在实验工况下海水析晶结垢是一种扩散控制过程。The seawater heat exchangers are generally used in direct current system or recycle system of electric power and petrochemical industry, while the seawater frequently causes crystallization fouling in the heat exchanges. The paper built a visual system to investigate the composition and kinetic mechanism of seawater crystallization fouling. The crystallization fouling composition and crystal structure were ana- lyzed by SEM, EDX and XRD. The results show that the composition and crystal structure of seawater fouling are both Mg6A1z （OH）is ＂ 4.5H20. Based on the Kern-Seaton model, a new crystallization-fouling kinetic model was proposed in the paper. The experimental data of different conditions were fit to the mod- el, and the kinetic parameters were obtained. The apparent activation energy of seawater crystallization- fouling is 1.54 x 104 J/mol,which is much close to the diffusion free energy of fouling-ions in seawater. Itmeans that the forming process of seawater fouling is controlled by diffusion.

关 键 词：物相分析 结晶动力学 析晶污垢 海水 换热器 

分 类 号：TK172[动力工程及工程热物理—热能工程]