Abstract: The process of LNG rolling evolution was simulated after stratification according to control equation of the process of rolling in LNG spherical tank, based on VOF model and boussinesq. Numerical analysis of the affecting factors for the roll. Research shows that the root cause of rolling for LNG is layering. The average convection velocity increased in the tank is followed with increasing of the quantity of environment heat leakage, accelerated the roll time of LNG. LNG rolling time could be lag because of large differences density in layered area but natural convection is severe within the layer. Roll will get the evaporation rate gather in the lower then caused the pressure augment and serious harm in the tank in a moment. Finally, some suggestions to prevent rolling were given. Providing theoretical guidance for LNG safety storage and optimize operations.

Key words: LNG, Layer, Rolling, Numerical calculation

摘要： 基于VOF模型和boussinesq假设建立了LNG球罐翻滚过程的控制方程，数值模拟了LNG分层后的翻滚演化过程，并对影响翻滚的因素进行数值分析。研究表明，LNG分层是产生翻滚的根本原因，且随着环境漏热量的相对增大，罐内流体的平均对流速度增加，加速了LNG的翻滚时间。分层区密度差异相对越大，可滞后LNG翻滚时间，但层内自然对流剧烈。一旦发生翻滚将会使下层蒸发率聚增，引起罐内压力瞬间过大，造成严重危害。给出了预防翻滚的几点建议,可为LNG安全存储和优化运营提供理论指导。

关键词: 液化天然气, 分层, 翻滚, 数值计算