파공 크기에 따른 이산화탄소 저장 탱크의 유출 특성에 대한 수치해석 연구

Abstract

The main objective of the present study is to numerically investigate the gaseous leakage characteristics inside CO2 gas tanks implemented in a ship. For achieving this purpose, thermal and flow characteristics were examined for different crack sizes and crack locations by using the commercial CFD code (ANSYS Fluent V. 13.0). To estimate the mass flow rate of CO2 at a crack location, the commercial code of PHAST using the phase change and orifice models was first used and its prediction was implemented in the CFD analysis. In this study, a new concept of effective diameter was introduced to account for the evaporation length and effective area of liquefied CO2 with the use of atomization model at the crack position. From numerical analysis, it was found that CO2 gas rapidly spreaded with time when leakage occurred, and substantial change in gas mixture pressure and temperature was observed for different crack sizes. Also, the CO2 concentration at 2 m from the bottom was estimated to be higher than a hazardous limit of 10% within 200 seconds for all cases. These results would be useful in evaluating the safety of CO2 cargo system and in designing more efficient gas detection system in a ship.rack sizes and crack locations by using the commercial CFD code (ANSYS Fluent V. 13.0). To estimate the mass flow rate of CO2 at a crack location, the commercial code of PHAST using the phase change and orifice models was first used and its prediction was implemented in the CFD analysis. In this study, a new concept of effective diameter was introduced to account for the evaporation length and effective area of liquefied CO2 with the use of atomization model at the crack position. From numerical analysis, it was found that CO2 gas rapidly spreaded with time when leakage occurred, and substantial change in gas mixture pressure and temperature was observed for different crack sizes. Also, the CO2 concentration at 2 m from the bottom was estimated to be higher than a hazardous limit of 10% within 200 seconds for all cases. These results would be useful in evaluating the safety of CO2 cargo system and in designing more efficient gas detection system in a ship.