船舶LNG储槽晃荡热动响应特性分析

Thermodynamic response analysis of sloshing ship in marine LNG storage tank

储运LNG船舶在航行中受外界环境影响,储槽内LNG液体出现晃荡,以及储槽维护结构的漏热,使得储罐内温度和压力变化,LNG出现相变,导致LNG的耗损及安全隐患。针对在晃荡和外界漏热影响下船舶LNG储槽热质传递过程,利用气-液两相VOF模型,建立了描述LNG储槽热动响应的数学模型,分析了在不同外部漏热、晃荡幅度和储槽内LNG液位高度下,储槽内LNG损耗及其热质传递特性,以及LNG储槽内自由液面波动。随着外部漏热上升,振幅和频率增加,使得LNG气相区压力增加和LNG损耗率增大,并随槽内LNG液位降低时,其增加的幅度相对较大。本文分析结果,可为优化船舶LNG储槽结构和LNG储槽的运行管理提供一定理论指导。

The LNG ship is affected by the external environment during the voyage,the sloshing of the LNG liquid in the storage tank,and the leakage heat of the maintenance structure of the storage tank,which causes the temperature and pressure in the storage tank to change,and the phase change of LNG leads to the loss of LNG and the safety hazard..Aiming at the heat and mass transfer process of LNG storage tanks under the influence of sloshing and external heat leakage,a gas-liquid two-phase VOF model was used to establish a mathematical model describing the thermal response of LNG storage tanks,and the leakage and sloshing amplitudes in different externalities were analyzed.And the LNG loss and its heat and mass transfer characteristics in the storage tank and the free surface fluctuation in the LNG storage tank under the height of the LNG liquid level in the storage tank.As the external leakage heat rises,the amplitude and frequency increase,so that the LNG gas zone pressure increase and the LNG loss rate increase,and the increase rate is relatively large as the LNG liquid level in the tank decreases.The analysis results in this paper can provide some theoretical guidance for optimizing the operation of LNG storage tank structure and LNG storage tank.