A dynamic thermodynamic model for LNG cargo tanks under voyage conditions considering buoyancy frequency correction factor

Understanding the self-pressurization rate and the vapor–liquid heat transfer mechanism in LNG storage tanks is essential for ensuring the safe and efficient operation of LNG carriers during maritime operations. This study used Thermal Equilibrium Model (TEM) and Dynamic Thermal Multi-Zone Model (D-TMZM) to estimate the thermodynamic behaviors of pressurization and vapor–liquid heat transfer in an LNG storage tank accurately. Actual operational data from an LNG carrier was used for model validation and parameter tuning. The results indicate that the vapor–liquid interfacial heat transfer coefficient is dynamically influenced by the degree of thermal stratification and the discharge flow rate. Under laden conditions, where stratification is weak and the vapor region is limited, the TEM provides sufficient prediction accuracy. In contrast, under ballast conditions, the thermodynamic behavi…