套管结构对翅片管气化器结霜特性的影响

结霜会对不同类型气化器造成长效性能的衰减.为研究套管结构对强化传热与表面结霜效果的影响,本文搭建了实验台,在普通传热管内加装套管,以液氮为工质,根据不同套管内径(Φ6、Φ8、Φ10 mm)及入口流量,设计了12组实验工况进行研究,获得翅片管表面不同测点处温度、霜层厚度及翅片管出口流体温度等参数.结果表明:入口流量为2....

Effect of Double-wall Heat Transfer Tube on Frosting Characteristics of Finned-tube Vaporizer

The degradation of the long-term performance of different types of vaporizers is caused by frosting.An experimental platform was built to study the effect of a double-wall heat transfer tube on heat transfer enhancement and frosting.In the experiment a tube was added to the inner side of the ordinary heat transfer tube and liquid nitrogen was used as the working medium.Twelve working conditions were designed based on different inner diameters(Φ6 mm,Φ8 mm,Φ10 mm)of double-wall heat transfer tubes and inlet flow.The temperature at different measuring points on the surface of the finned tube,the frost thickness,and the fluid temperature at the outlet of the finned tube were tested.The results show that when the inlet flow is 2.5 g/s,the outlet temperatures of the ordinary heat transfer tube,and double-wall heat transfer tube with inner diameters ofΦ6 mm,Φ8 mm,andΦ10 mm are 193 K,205 K,200 K,and 199 K,respectively.This means that compared with the ordinary heat transfer tube,the double-wall heat transfer tube effectively delays the frost growth.Among the three tube specifications,the double-wall heat transfer tube with an inner diameter ofΦ6 mm has a better effect on delaying the growth of frosting.When the inlet flow is 2.5 g/s,3.5 g/s and 4.5 g/s,using a double-wall heat transfer tube with an inner diameter ofΦ6 mm,the lower inlet flow can delay frosting on the fin surface.