Frost behavior in ambient air vaporizer

Abstract

A vaporizer is a device for vaporizing cryogenic liquids such as liquefied natural gas (LNG) using a high-temperature heat source. Among the various types of vaporizers, the ambient air vaporizer (AAV) uses air in the atmosphere as the heat exchange medium; therefore, it is regarded as an eco-friendly heat exchanger. However, owing to the fuzziness and frost formed on the surface of the AAV, the vaporization efficiency decreases. In this study, the frost generation and formation on AAVs were investigated. For evaluation of the AAV performance, the outlet temperature of the LNG and the thickness of the frost layer formed were observed for different numbers of fins and effects of different seasons. Finally, these were also measured considering different convective heat transfer coefficients to observe the effect of different convective conditions; in this case, the outlet temperature of the LNG was not influenced by different seasons. However, the frost thickness was found to be affected by different seasons.