LNG船液货装卸系统仿真计算与实现

Simulation Calculation and Implementation of LNG Carrier Liquid Loading and Unloading System

液化天然气(LNG)船液货装卸过程中,需严格控制装卸时间,但由于装卸系统的复杂性,设计装卸系统时很难准确得到LNG在管路中的流动状态平衡控制。针对上述问题,提出了一种面向LNG船液货装卸系统结构的计算方法,根据图论和有限元软件构建装卸系统拓扑模型,形成双层反馈控制结构,建立仿真装卸模型,计算任意时间点的管网节点压头和管路流量情况。采用Visual C++编制了图形化界面的仿真计算软件进行仿真。仿真结果与实际情况基本符合,表明装卸方法具有实用性,能对LNG船液货装卸系统的设计起借鉴作用。

It is necessary to control the loading and unloading time in the progress of LNG carrier＇s loading and unloading task. Because of the complexity of pipe system, LNG＇s flow condition is hard to be estimated in the design of loading and unloading system. To solve this question, the paper proposed and implemented a simulation calculation method for LNG carrier＇s liquid loading and unloading system. This method constructed system topologies based on graph theory and finite element conception, formed a bilayer feedback control structure, simulated loading and un- loading progress, and calculated the node pressure head and flow condition of pipe net on any time. Using Visual C ＋ ＋ programmed Graphical interface simulation software,the data obtained from simulation complied with the actual data, which shows the practicability of this method. This method can be a reference to the design of LNG carrier＇s loading and unloading system.