摘要
在不同喷淋量Q、管间距S、布液高度H下对半椭圆管水平降膜液膜厚度变化进行研究,同时与圆管、椭圆管的液膜厚度进行了对比,运用图像数字化处理得到降膜过程的气液界面线以及半椭圆管液膜厚度随管壁周向角变化情况。结果表明:对于相同截面周长的圆管、椭圆管和半椭圆管,在相同工况下,半椭圆管的平均液膜厚度最小;随着喷淋量的增加,液膜厚度先增加后变小;随着布液高度的增加,液膜厚度逐渐变薄;随着管间距增加,液膜厚度逐渐变薄;截面周长为79.8 mm、长短轴比为2.1的半椭圆管在喷淋量Q为0.14 L/min、布液高度H为15 mm、管间距S小于20 mm,液膜厚度稳定,有利于充分换热。
The changes of the film thickness of the falling film in the semi-elliptical tube were studied under different spray flows（Q）, tube pitch（S） and the height of liquid distributor（H）, and the thickness of the liquid film of the tube and oval tube was compared, the gas-liquid interface line of falling film process and the variation of liquid film thickness of semi elliptical tube with the circumferential angle of tube wall were obtained by digital image processing. The results show that： For the same section perimeter tube, oval tube and semi elliptical tube, under the same conditions, the average film thickness of semi elliptical tube with minimum; With the increase of spray flow, the thickness of liquid film increases at first and then decreases; with the increase of the height of liquid distributor,the film thickness becomes thinner; With the increase of tube pitch, the thickness of liquid film thinning. It is stable that the thickness of liquid film covering with the semi elliptical tube whose circumference is 79.8 mm and whose ratio between long and short axes is 2.1, in the condition of a spray flow around 0.14 L/min, H is 15 mm and S less than 20 mm, which is beneficial to the full heat transfer.
作者
彭泰铭
周亚素
胡昊
颜子雄
PENG Tai-Ming, ZHOU Ya-Su ,HU Hao, YAN Zi-Xiong(School of Environmental Science and Engineering, Dong hua University Shanghai 201620, Chin)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2018年第9期2040-2047,共8页
Journal of Engineering Thermophysics
关键词
半椭圆管
液膜厚度
喷淋量
管间距
布液高度
图像数字化
semi-elliptical tube
film thickness
spray flow
tube pitch
the height of liquid distrib-utor
digitized images processing
