Heat Transfer and Evaporation Mathematical Model of LNG covered by High Expansion Foam

Abstract

With the expanding of liquefied natural gas (LNG) usage, its security hidden trouble appeared gradually. For security reasons, small-scale experiment was carried out using LN2 (whose thermal physical property parameters is similar to that of LNG, and do not affect the validity of the study) instead of LNG. Observing high expansion foam physical structure after it covering LN2, we find out there's a three layer structure above the LN2 at stable stage, the ice layer (including the tentacles below), freezing foam layer and the foam layer. Through observation and analysis, we build a physical structure model of the foam. A new method to calculate thin film thickness using expansion ratio is proposed, and a heat transfer and evaporation model between foam and LNG in the initial stage is established. Also we build a physical structure model of the ice, and establish a heat transfer and evaporation model between ice and LNG in stable stage. Combined with heat transfer between LNG, ground and cofferdam, the heat transfer and evaporation model of LNG covered with foam was developed eventually.