Session: 06-11-03 Ocean Engineering Technology III

Paper Number: 126242

126242 - Long Term Prediction of Boil-Off Gas in a Type-C Cryogenic Storage Tank Using Thermodynamic Equilibrium Model and Phase Transform Between Liquid and Ullage 

This paper addresses the prediction of Boil-Off Gas (BOG) in a Type-C Liquid Natural Gas (LNG)  or Luquid hydrogen storage tank. Utilizing liquid nitrogen in a tank used for the fuled tank, we predicted the BOG production and temperature over a period of approximately one week and compared the numerical predictions with experimental results. The convection heat flux entering from outside the tank, the increase in internal pressure and changes in temperature within the tank, as well as the evaporation and condensation of the liquid, were all modeled as multi-phase thermal flow and thermal diffusion phenomena. While the Computational Fluid Dynamics (CFD) method can detail multi-phase thermal flow phenomena including evaporation and condensation, it requires high computational performance and extensive analysis time for long-term BOG prediction. On the other hand, the Thermodynamic Equilibrium Model (TDM) technique, while incorporating phase change characteristics, could allow for rapid calculations of long-term BOG through the use of thermal networked of heat diffusion capacities, energy conservation, and convective boundary layers. We presented the TDM of thermal conductive lumped masses of liquids and gases required to implement the BOG phenomenon, as well as the networks for thermal equilibrium and energy conservation, the phase changes between liquid and gas, evaporation and condensation, the generation of convective boundary layers, and the convection heat transfer phenomena inside and outside the tank. Specifically we presented the TDM modeling process with SINDA/FLUINT and the results of predicting BOG in cryogenic tanks. In the analytical process, the initial conditions of the experiment were implemented by reflecting the heat flux and mass change aligned with phase change affected by the the tank’s cool down and bunkering. By simulating the BOG experiment introduced in previous related papers with cryogenic tank, and comparing the predicted temperatures and BOG values with measured values, we discussed the validity of the prediction model. Finally, the results of predicting BOG in a Type C cylinderical tank were presented.
 

Presenting Author: Min-Seok Kim INHA University

Presenting Author Biography: Min-Seok Kim is a Doctor Coarse student at the Inha University, Korea. He graduated from the University of Inha in 2020 with a Master's Degree in Naval Architecture & Ocean Engineering. Min-Seok is interested in topics related to the LNG CCS, Green Ship, Two phase flow, Cryogenic storage tank, BOG/BOR, etc.

Authors:

Min-Seok Kim INHA University
Jaedeok Yoon INHA University
Jang Hyun Lee INHA University