换热面上颗粒污垢生长特性的数值模拟研究  

Numerical Simulation of Particle Fouling Growth Characteristics on Heat Transfer Surface

作　　者：张宁[1] 李楠[1] 杨启容[1] 钟浩文 颜鲁 ZHANG Ning;LI Nan;YANG Qirong;ZHONG Haowen;YAN Lu(School of Electromechanic Engineering,Qingdao University,Qingdao 266071,China)

机构地区：[1]青岛大学机电工程学院,山东青岛266071

出　　处：《青岛大学学报（工程技术版）》2018年第1期75-79,86,共6页Journal of Qingdao University(Engineering & Technology Edition)

基　　金：山东省自然科学基金资助(ZR2015EM003)

摘　　要：针对颗粒污垢在换热器中存在的沉积问题,本文采用计算流体力学(computational fluid dynamics,CFD)方法,借助Fluent软件,对换热面上颗粒污垢生长特性进行数值模拟,模拟了二氧化硅颗粒在圆管内的沉积过程,并结合相关经验公式,建立颗粒污垢剥蚀模型。模拟结果表明,二氧化硅颗粒在流速、入口温度和管壁粗糙度这3种运行工况下,其污垢热阻先增加后趋于平稳,一段时间后达到一个渐近值。随着流速的增加,颗粒结垢速率和污垢热阻渐近值逐渐减小;随着入口温度的增加,污垢热阻渐近值逐渐减小;随着管壁粗糙度的增加,污垢热阻渐近值和达到渐近值的时间都逐渐增大。因此,通过增大流速和入口温度,减小管壁粗糙度,可减小换热面上的颗粒污垢热阻。该研究为实际生产过程中的抑垢和除垢技术提供了理论参考。In order to solve the problem of particle fouling in heat exchangers,the deposition process of silica particles in circular tubes was simulated by Fluent using CFD method.Combining the relevant empirical formula,a particle fouling denudation model is established.The particle deposition rate is obtained by numerical simulation and the denudation rate is calculated according to the empirical formula.The net deposition rate and the particle fouling thermal resistance are obtained.The results show that the thermal resistance of silica particles fouling increases first and then tends to be stable,reaching an asymptotic value after a period of time under the three operating conditions.With the increase of flow rate,the scaling rate and asymptotic value of fouling thermal resistance decreases;with the increase of entrance temperature,the asymptotic value of fouling thermal resistance decreases;with the increase of pipe wall roughness,the asymptotic value of fouling thermal resistance and time reaching to asymptotic value increases.By investigating the influence of operating conditions on the growth characteristics of silica particles on the heat transfer surface,it is of important reference value to scale inhibition and removal in the actual production process.

关 键 词：二氧化硅颗粒 数值模拟 沉积 剥蚀 污垢热阻 渐近值 

分 类 号：TK172[动力工程及工程热物理—热能工程]