-60℃水平圆管表面结霜特性的实验研究

In order to study the frosting behavior on the cold surface at -60℃, a test rig based on cascade refrigeration system for frosting visualization on the surface of horizontal circular tube is designed and built. The frosting behavior on the outer surface of the horizontal tube in the channel of double-pipe heat exchanger was tested when the moist air was sweeping down the tube. The thickness and growth rate of frost were emphatically analyzed. The results showed that the growth rate of the frost thickness on the surface at -60℃ is faster than that on the cold surface at ambient temperature, which is about twice as fast as that on the cold surface at -15℃. However, the growth trends of both are similar. In addition, two different melting processes, i.e., the periodic melting and the rapid falling of the frost caused by collapse, were found and analyzed. The thickness of the frost layer is greatly reduced due to collapse and melting. The frosting behavior on the horizontal tube surface at -60℃ in the confined channel is preliminarily explored, which enriches the experimental data of frosting behavior and lays a foundation for more comprehensive and systematic experimental research in the future.