Quantitative Analysis of Frosting Characteristics on the Drip Tray of A Cryogenic Valve for LNG Ships

Cryogenic valves play a crucial role in the production and transportation of liquefied natural gas (LNG), and are primarily responsible for efficiently controlling the inflow and outflow of LNG and regulating pressure. However, due to their operation in low-temperature and high-humidity environments, crucial components such as drip trays are susceptible to frosting, which may lead to LNG leakage, thereby causing severe safety incidents. In this study, the user-defined function (UDF) is employed to redevelop Fluent, which integrates the frost growth model with the Eulerian multiphase flow model, to conduct a quantitative analysis of frosting on drip trays of cryogenic valves. The effects of environmental parameters, such as wind speed, ambient temperature, air humidity, and cold surface temperature on the growth of the frost layer were analyzed. This study reveals a limiting wind speed between 1 m/s and 2 m/s. Upon reaching this limit speed, the growth of the frost layer reaches its maximum, and further increases in the wind speed have no significant effect on the growth of the frost layer. Furthermore, the influence of the change in the flow field on droplet impingement and freezing during the growth of the frost layer is considered through the coupling method of the kinematic characteristics of water droplets and the collection coefficient of water droplets. This study identifies the influence of different parameters on the droplet impact efficiency, leading to the modification of the frost layer on the drip tray.