LNG MIXING BEHAVIORS INCLUDING BUBBLES OBSERVED DURING THE BOTTOM FILLING OF HEAVIER LNG IN LNG MIXED STORAGE

摘要

Tokyo Gas has succeeded in becoming the first in the world to observe and record visually the phenomenon where heavier LNG deposited from the bottom-filling nozzle in an LNG tank under operation did not remain at the bottom of the tank and moved against gravity to rise to the top.The observation of this unique and physically contradictory phenomenon was performed under the condition where heavier LNG was intentionally deposited from the bottom-filling nozzle,unlike the ordinary operation to promote mixing.An LNG tank internal observation device,the only one in the world and developed by Tokyo Gas,made it possible to successfully observe and visually record the phenomenon.The results clearly show that heavier LNG rises from the bottom nozzle.It was also observed that bubbles appeared to mix with the LNG during the filling of the storage tank.This paper describes LNG mixing behaviors focusing on these results.In clarifying this phenomenon,depositing heavier LNG from the bottom of a storage tank,which is considered to always cause stratification,will become possible in a safe manner.With the detailed clarification of the mechanism and its application to a simulation model now being researched,it is expected that this achievement will contribute to further growth of the LNG industry through use of simulation technology developed by Tokyo Gas.