超亲/疏水性表面池沸腾传热研究  

Pool boiling heat transfer on superhydrophilic and superhydrophobic surfaces

作　　者：郑晓欢[1] 纪献兵[1] 王野[1] 徐进良[1] 

机构地区：[1]华北电力大学多相流动与传热北京市重点实验室,电站设备状态监测与控制教育部重点实验室,北京102206

出　　处：《化工进展》2016年第12期3793-3798,共6页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51276061,51436004);中核核反应堆热工水力技术重点实验室开放基金项目

摘　　要：为研究超亲/疏水性表面对沸腾传热的影响,用H_2O2氧化的方式制备了超亲水表面,用氨水加高分子修饰的方式制备了超疏水表面。在常压下以蒸馏水为工质,采用高速摄影仪对其进行了池沸腾传热实验。结果表明,超疏水表面亲气疏水,在沸腾起始点易于产生气泡,且气泡不易脱离,此时壁面过热度ΔTs仅为2.4K,但随热流密度的增大,气泡易于聚合,所产生的大气泡阻碍了传热的进行,传热开始恶化,临界热流密度(CHF)较低;而H_2O2氧化的表面由于刀片状微纳结构的存在,增加了表面的粗糙度,不仅增大了相变传热表面积、增加了核化点数量,而且具有超亲水特性,气泡脱离频率较大,大大强化了沸腾传热,最大换热系数约是光表面的1.7倍,且相应地提高了CHF,可达131.0W/cm2,表现出较好的传热特性。Experiments were conducted to study the effect of super hydrophilic/hydrophobic surface on the pool boiling heat transfer.The superhydrophilic surface was prepared by H_2O_2 oxidation and the superhydrophobic surface was prepared by ammonia immersion and high molecular material modification.In the experiments a high speed camera was used to record the process of bubble growth,using water as the working fluid at atmosphere pressure.It is found that for superhydrophobic surface the bubbles were easy to generate and not easy to detach at the onset of nucleate boiling accompanied by good heat transfer performance and low surface superheat.The surface superheat was only 2.4K.With the increase of heat flux,the bubbles were easy to merge and form large ones,which block the heat transfer and make surface have low critical heat flux（CHF）.However,for superhydrophilic surface the existence of micro-nano sheet structure increased the surface roughness,it not only increased heat transfer area and the number of nucleate sites,but also made surface have superhydrophilic characteristic.So the bubble departure frequency was large and the boiling heat transfer was enhanced greatly.The maximum heat transfer coefficient was nearly 1.7 times than that of plain surface and the CHF can be improved to 131.0W/cm^2,which showed better heat transfer performance in pool boiling.

关 键 词：润湿性 微纳结构 池沸腾 超亲水 超疏水 

分 类 号：TK124[动力工程及工程热物理—工程热物理]