ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
AN EXPERIMENTAL STUDY ON FROST DEPOSITION ON A VERTICAL CRYOGENIC SURFACE UNDER NATURAL CONVECTION
摘要
A series of experiments was carried out to investigate the frost growth on a vertical flat cryogenic surface under
natural convection. The results show that when the cold surface temperature below a certain value, the frost
layers tend to grow from the top downwards along the cold surface. The vertical growth velocity and frost layer
thickness would be influenced by the air relative humidity significantly, whereas the influences of cold surface
temperature are very weak. The growth patterns of frost layers in vertical direction can be classified into nonlinear growth and linear growth. When the frost layer growth pattern is single dendritic growth, its growth is
linear, frost layers have quite similar vertical growth velocities if air relative humidity is the same in different
experiments. When there are clusters of frost crystals grow from the bottom up at the front ends of the main frost
layer, the growth pattern is non-linear, the non-linear growth slows down the vertical growth velocity. The
growth pattern of frost layer at the early stage has essential effects on frost deposition in the long run, which can determine the mass transfer or at least the frost thickness of the frost deposition process.