竖直环形流道内欠热沸腾时的气泡行为研究  

Vapor Bubble Behavior in Sub-Cooled Flow Boiling in Vertical Annular Ducts

作　　者：孙立成[1] 阎昌琪[1] 孙中宁[1] 

机构地区：[1]哈尔滨工程大学核科学与技术学院,150001

出　　处：《核动力工程》2006年第z1期73-76,共4页Nuclear Power Engineering

基　　金：哈尔滨工程大学基金项目(HEUF040126)

摘　　要：一般在沸腾传热实验中壁面的加热方式有电加热和流体加热两种,流体加热方式下的沸腾传热研究进行得很少。在水加热条件下,对水在竖直环形流道内欠热流动沸腾时的气泡行为进行了可视化研究。环隙宽度为5mm和3mm两种,质量流速分别为16.8～55.3kg/(m2.s)和15.3～62.1kg/(m2.s)。可视化实验结果表明:在贴近壁面的区域存在气泡运动层,大部分气泡在气泡运动层内运动。在宽度为3mm的流道中,气泡在脱离壁面前一般会滑动;滑动距离不超过2～3倍气泡直径,并且存在反复胀缩的现象。5mm流道内的气泡则较少发生滑动,往往在脱离壁面后会被弹回壁面。气泡的滑动和离开壁面后又返回壁面的运动方式是沸腾具有高强度传热能力的原因之一。In the boiling heat transfer setup,the two commonly methods to heat the test section wall are electric heating and fluid heating,and the boiling heat transfer for the latter is seldom studied.The boiling heat transfer characteristics under the two heat methods are different.Visualization research has been con-ducted on the bubble behavior of sub-cooled flow boiling water in vertical annular ducts heated by water.The duct widths are 5mm and 3mm,and the mass flux ranges are 16.8～55.3 kg/(m2.s) and15.3～62 kg/(m2.s),respectively.The results show that there exists a bubble layer near the wall,and most bubbles move in the layer.Most bubbles in 3mm annulus will slide for a distance not more than 2～3 times of the bubble diameter and keep expanding and shrinking for several times before departure.On the contrary,most bubbles in 5mm duct scarcely slide and are always bounced to the wall after departure.All these bubble behavior should be one of the reasons that the boiling can enhance heat transfer greatly.

关 键 词：欠热流动沸腾 竖直环形流道 气泡行为 水加热 

分 类 号：TL334[核科学技术—核技术及应用]