Work

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

Year: 2026

Type: article

Abstract: 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 behavior highly depends on cases due to variations in vapor stratification and discharge flow rate. The proposed D-TMZM with a buoyancy frequency correction factor well captures the changes pressurization and BOR behavior which depend on operating conditions. A contribution analysis is conducted to analyze how vapor heating and vapor mass variation contribute to pressurization, which supports clearer interpretation of operating-condition effects on BOR and pressure response.

Source: Case Studies in Thermal Engineering

DOI: 10.1016/j.csite.2026.108443

Authors: Taehun Nam, Youngsub Lim

Institution: Seoul National University

Language: English

Topic: Spacecraft and Cryogenic Technologies

Subfield: Aerospace Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $1,620