R141b在烧结高通量管外流动沸腾换热实验研究  

Flow Boiling of R141b on Externally Sintered High-Flux Tubes

作　　者：王科 赵学智 叶晶 揭涛 WANG Ke;ZHAO Xuezhi;YE Jing;JIE Tao(College of Mechanical and Transportation Engineering,China University of Petroleum-Beijing,Beijing 102249,China;Shanghai Marine Diesel Engine Research Institute,Shanghai 201100,China)

机构地区：[1]中国石油大学(北京)机械与储运工程学院,北京102249 [2]中国船舶集团有限公司第七一一研究所,上海201100

出　　处：《工程热物理学报》2024年第8期2389-2395,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金项目(No.52376157)。

摘　　要：烧结型高通量管是一种新型的强化换热元件,能在较低的壁面过热度条件下产生剧烈的核态沸腾,促进工质的相变换热。为探究烧结多孔层对流动沸腾换热特性的影响规律,本文以制冷剂R141b为实验工质,对外径为25 mm、涂层厚度为0.3mm、孔隙度分别为65%和75%的外烧结型高通量管开展了实验研究。结果表明,在相同的壁面过热度条件下,高通量管较光管能大幅提高壁面热流密度,且孔隙率更高的高通量管其壁面热流密度更高。增加高通量管的孔隙度能增加汽化核心的数量和汽泡脱离的频率,但当加热壁面温度升高到一定程度时,汽泡无法及时从多孔层中逃逸而形成局部汽膜,导致高通量管的换热系数降低。The sintered high-flux tube is an innovative heat transfer element that exhibits enhanced heat transfer capabilities.It is capable of inducing vigorous nuclear boiling even at low wall super-heat conditions,thereby facilitating the efficient heat transfer of the working medium.In order to investigate the impact of a sintered porous layer on the characteristics of flow boiling heat transfer,this study conducted experimental research on externally sintered high-flux tubes.The tubes had an outer diameter of 25 mm,a coating thickness of 0.3 mm,and porosities of 65%and 75%respec-tively.The experimental working medium used in this study was refrigerant R141b.The results indicate that,when subjected to identical wall superheat conditions,the high-flux tube exhibits a substantial increase in wall heat flux compared to the smooth tube.Furthermore,it is observed that the high-flux tube with greater porosity demonstrates an even higher wall heat flux.Increasing the porosity of the high-flux tube has been found to have a positive effect on the number of vaporized cores and the frequency of bubble detachment.However,it should be noted that when the heating wall temperature reaches a certain threshold,the bubbles are unable to escape from the porous layer and instead form a localized vapor film.This phenomenon ultimately leads to a decrease in the heat transfer coefficient of the high-flux tube.

关 键 词：高通量管 强化换热 流动沸腾 过冷沸腾 R141B 

分 类 号：TK124[动力工程及工程热物理—工程热物理]