Methodology for Stable Dynamic Simulation of a LNG Pipe under Two-Phase-Flow Generation

초록

The results of dynamic simulations can become unstable because of a steep change in the calculated variables. In particular, when liquefied natural gas (LNG) begins to vaporize and a two-phase flow is generated, the simulation results can become violently oscillatory because of the significant volume difference between natural gas in the vapor phase and LNG in the liquid phase. To ensure more stable simulation results, we developed a methodology for replacing a unit module selectively. When LNG started to vaporize, the unit module at the point where the two-phase flow was first generated was replaced by a more stable unit module. This methodology was evaluated through a case study of a LNG pipeline model and led to more stable simulation results.