新型液化天然气船液货围护系统传热模型及蒸发率计算

分析了一艘170000m3新型液化天然气船的船体结构,通过合理和必要的简化,建立了液货围护系统的传热模型。分别使用解析方法和ANSYS Fluent软件数值模拟方法计算了在不同绝热层厚度条件下的液货舱漏热量,得到不同条件下液货围护系统的温度场分布情况以及液货蒸发率。得出以下结论:综合考虑两种计算方法的计算结果,为了满足在不同工况下航行时液货的日蒸发率不能超过0.1%的要求,绝热层的设计厚度应不小于450mm。

Heat transfer model and BOG calculation for the containment system of a new-type LNG carrier

Based on the analyses of the hull and containment system structure of a new-type LNG carrier with the total capacity of 170,000m^3, by taking into account of reasonable and necessary simplification, the heat transfer model of the containment system is established. An analytical method and ANSYS Fluent software are used to calculate the total heat transfer rate between the liquid cargo tank and its surroundings, to obtain the temperature fields of the containment system and the boil off rate of LNG for the different thickness of thermal insulation layer. The following conclusion is obtained: The thickness of the thermal insulation layer should be not less than 450mm, in order to meet the requirement that the boil off rate of LNG is less than 0.1% per day.