LNG卸料管线预冷过程数值模拟

国内对液化天然气(LNG)接收站初次预冷速度的控制经验相对缺乏。因此,为防止低温LNG预冷导致的管道的损坏,需在预冷前对设定的预冷操作程序进行预冷效果的分析校核。本文提出了基于计算流体力学(CFD)的LNG管道预冷分析方法。通过建立三维LNG卸料管道数值计算模型,根据国内某LNG接收站项目设计管道预冷操作程序,进行冷却过程的动态模拟计算,结果显示按预设冷却程序操作,LNG卸料管道降温速度可以维持在10℃/h范围内,满足预冷安全要求。另模拟计算结果与实际接收站预冷过程的现场测量数据进行了对比,CFD计算值与实测值比较相对误差可控制在7%以内,证明CFD预冷过程模拟完全可以用于接收站预冷程序合理性的判断和校核计算。

Numerical simulation of LNG unloading pipeline pre-cooling process

Domestic LNG receiving terminal lack of cooling speed control experience. In order to prevent damage caused by cryogenic LNG suddenly flowing into unloading pipeline,verification of the effect of the pre-cooling operation procedure must be carried out before pre-cooling operation. A computational fluid dynamics (CFD) based analysis method is proposed in this paper. A 3D CFD model is built based on a domestic LNG receiving terminal project pre-cooling procedure,and dynamic simulation is carried out for checking the pre-cooling process. The cooling rate of LNG unloading pipe can be maintained within 10℃/h,and meet the pre-cooling safety requirement. The CFD calculation results are compared with actual measurements on site. The accuracy of numerical simulation for pre-cooling could be within 7% of test data. which proves that CFD calculation method can be used in confirming the rationality of LNG receiving terminal's pre-cooling procedure and checking calculation.