Abstract:

Heat transfer characteristics about supercritical LNG in intermediate fluid vaporizer was investigated via numerical analysis and CFD simulation,and the influences of pressure and mass flow rate were studied.The result showed that the heat transfer coefficient and the wall temperature fluctuated as the LNG temperature increased,and changing mass flow fate seemed no use about this.In addition,the simulation result showed that the heat transfer deterioration occurred when LNG was near critical region,and the main reason was the properties' sharp change near critical region.Increasing the mass flow rate seemed a effective way to avoid heat transfer deterioration.

Key words: natural gas, methane, supercritical fluid, heat transfer, numerical simulation

摘要：

利用一维数值计算与CFD数值模拟的方法对中间介质气化器中超临界LNG的换热情况进行了研究。分析了工作压力与质量流量对LNG超临界换热的影响。结果表明在较低压力下,超临界LNG的传热系数及壁温会出现波动的现象,而改变质量流量对这种现象影响不大。除此之外,数值模拟结果表明,低流量工况下,超临界LNG在临界区附近由于物性的剧烈变化会发生传热恶化现象,而常用的换热关联式不能很好地预测这一现象,适当提高入口流量可以有效避免传热恶化现象的发生。

关键词: 天然气, 甲烷, 超临界流体, 传热, 数值模拟