Evaluate the Performance of Vertical and Horizontal Liquefied Natural Gas Storage Tanks by Using a Non-Equilibrium Resistance-Capacitance Model

Abstract

Abstract Methane is the primary component of liquefied natural gas (LNG) and a potent greenhouse gas (GHG). The undesired methane emissions across the natural gas supply chain has been proven to worsen the lifecycle GHG emissions from the transportation sector compared with diesel. Therefore, having accurate fast-response models to predict the performance of natural gas infrastructure, such as LNG storage facilities, becomes crucial to minimize methane emissions. In this study, a novel non-equilibrium multi-species thermodynamic model based on the resistance-capacitance network is developed to assess the thermal performance of LNG storage tanks. The accuracy of the non-equilibrium model is validated against the experimental data of a storage tank under dynamic hot gas injection. Then, the model is employed to analyze the performance of two identical vertical and horizontal storage tanks in a refueling station under self-pressurization condition. The results show that the pressure rise in the stationary vertical and horizontal tanks is similar. However, the temperature gradient between the vapor phase and LNG in the horizontal tank is less than that in the vertical tank due to the larger vapor-liquid interface. This feature allows the horizontal tank to reduce the tank pressure faster than the vertical tank under sudden pressure increase.