表面微结构对析晶沉积特性影响的格子Boltzmann模拟  

Lattice Boltzmann simulation of surface microstructure effect on crystallization fouling

作　　者：程成 段钟弟 孙浩然 胡海涛[3] 薛鸿祥[1] CHENG Cheng;DUAN Zhongdi;SUN Haoran;HU Haitao;XUE Hongxiang(State Key Laboratory of Ocean Engineering,Shanghai JiaoTong University,Shanghai 200240,China;China Ship Research and Development Academy,Beijing 100101,China;School of Mechanical Engineering,Shanghai JiaoTong University,Shanghai 200240,China)

机构地区：[1]上海交通大学海洋工程国家重点实验室,上海200240 [2]中国舰船研究院,北京100101 [3]上海交通大学机械与动力工程学院,上海200240

出　　处：《化工学报》2023年第S01期74-86,F0003,共14页CIESC Journal

基　　金：国家自然科学基金项目(52001207);上海市启明星项目扬帆专项(22YF1459700);中船集团-上海交通大学海洋装备前瞻创新联合基金资助项目(1-B1)。

摘　　要：析晶污垢是一种普遍存在于换热设备中的有害结晶,损耗设备的换热性能。在换热表面设置粗糙微结构对流动和换热影响显著,也使得表面的析晶污垢沉积机理变得十分复杂。基于析晶沉积动力学理论,建立了有限差分-格子动力学耦合模型,对碳酸钙在微细通道换热表面的沉积特性进行分析,并讨论表面微结构单元的分布间距和高度对结垢行为的影响。结果表明,建立的有限差分-格子动力学耦合模型能够有效模拟微结构背风面的局部涡流和换热表面的结垢过程;微结构分布间距的缩减和高度的增加均会明显使高壁温区域的析晶沉积过程由表面反应主导转变为传质扩散主导;与光滑换热表面的析晶沉积工况对比,微结构的设置及高度增加使换热表面污垢沉积量增多,相邻微结构间的涡也随沉积时间逐渐变小。Crystallization fouling is a type of harmful crystals that commonly exists in heat exchange equipment,which deteriorates heat transfer performance.Setting rough microstructures on the heat exchange surface has a significant impact on the flow and heat transfer,and also makes the deposition mechanism of crystallization fouling on the surface complicated.In this paper,a finite difference-lattice dynamic coupling model is established to analyze the deposition characteristics of calcium carbonate on the heat exchange surface of microchannels based on the theory of crystallization deposition kinetics.The influence of the microstructure spacing and height on the fouling behavior is discussed.The results show that the finite difference-lattice dynamic coupling model proposed can effectively simulate the local eddy current on the leeward side of the microstructure and scaling process of heat exchange surface.The decrease of the spacing and the increase of the height of the microstructure will obviously alter the domination of crystallization deposition process from surface reaction to mass transfer in the high-temperature wall area.Compared with the case of the smooth surface,the presence and increasing height of the microstructure facilitates the fouling deposition on the heat exchange surface,and the vortex between adjacent microstructures decreases gradually with the deposition time.

关 键 词：格子BOLTZMANN 传热 反应动力学 沉积物 微结构 

分 类 号：O795[理学—晶体学] TK124[动力工程及工程热物理—工程热物理]