Modeling and Analysis of Frost Growth in Pilot-Scale Ambient Air Vaporizer

Abstract

During the operation of an ambient air vaporizer (AAV) designed for vaporizing liquefied natural gas (LNG), the condensation of water vapor results in frost accumulation on the surface of the vaporizer tubes. The frost deposited on the surface lowers the heat transfer rate because the thermal conductivity of frost is less than 1/40 times the thermal conductivity of aluminum, which was used as the material for the tube and fin. It is essential to understand the behavior of frost accumulation because the actual challenge in this field is to predict frost growth in cryogenic conditions and the dynamic heat transfer performance of the AAV owing to frost. In this study, the formation of a frost layer on the surface of an LNG vaporizer and the reduction in heat performance are evaluated using a dynamic numerical model that combines heat transfer and mass transfer. The trend of frost growth and the temperature profile of LNG with position and time were studied by modeling and simulation. The numerical results pr...