窄通道内水沸腾换热的数值模拟研究

摘要

Here in the research we discuss the boiling heat transfer in three kinds of vertical narrow channels on fluent ,the length of them is 100 mm while the widths are 2 ,5 mm and 10 mm .In condition that gravity ,surface tension and the rough-ness of the surface have been taken into consideration ,the research simulates boiling process in narrow channels and explores how the width of the channel influences onset of nucleate boiling ,the import and export pressure difference ,average tempera-ture of the outlet and the average surface heat transfer coefficient .It is found that the higher export temperature ,average surface heat transfer coefficient ,the earlier ONB ;the smaller the flow speed at the entrance ,the earlier ONB and a little roughness is in favor of boiling heat transfer .%利用FLUENT软件模拟了间隙宽度为2，5，10 mm ，长度为100 mm的3种竖直窄通道内的沸腾换热过程。在考虑了重力、表面张力和壁面粗糙度影响的条件下，分析了通道间隙尺寸及入口流速等参数对ONB点、系统进出口压差、出口平均温度以及平均表面换热系数的影响。模拟结果为：对于相同入口流速的窄通道，间隙尺寸小的窄通道出口平均温度、进出口压差以及平均表面换热系数较大，ONB点产生较早。通道入口流速越小，ONB点产生越早；较小的粗糙度有利于窄通道的沸腾换热。