LNG 화물창 방열재 균열에 따른 액화천연가스의 열확산 및 기화 예측을 위한 수치 모델

초록

The thermal insulation layers in a LNG carrier is designed to maintain the LNG cargo at cryogenic temperature. The seepage of the cryogenic LNG through the cracks on the insulation membrane makes the hull structures experience the cold spot caused by the heat transfer from the LNG. The hull structure will become brittle at the cold spot. Also, the evaporated Natural gas may lead to a potentially hazard because of the flammable gases in it. The temperature distribution in the insulation panel and the speed of gas diffusion through the insulation panels have been expected to assess the safety of LNG carrier subject to leakage. The assessment of the behaviors of the leaked LNG requires a numerical calculation that can consider the multiphase flow in various flow regimes. This paper presents the numerical simulation of LNG flow and heat conduction in the LNG insulation panel subject to leakage. The simulation model considers the phase change of LNG, gas-liquid multiphase interactions in the porous media and the accompanied rates of heat transfer. It also applies the numerical simulation to the NO96-GW membrane storage assembled by glass wool and plywood. In the numerical simulation, the seepage, the heat diffusion, and the evaporation of LNG are investigated.