Numerical Analysis for Optimization of LNG Vaporizer

Abstract

Liquefied Natural Gas (LNG) is usually heated from cryogenic state by a heat exchanger before supply to consumers, a process generally called heating. A heat exchanger is a device which is used for transferring heat from one fluid to another fluid with the two fluids temperature difference. In this study, the cryogenic state LNG is passed through the tube side and heated by the hot Glycol-water on the shell side. To increase the efficiency of the system and reducing energy consumption, it is suggested that maximum heat gets extracted from hot Glycol-water and transferred to LNG stream. Hence, the present study compares different shell and tube sides arrangement system in order to check whether the assumed design satisfies all requirements or not. The shell side outlet temperature, tube side outlet temperature, pressure drop, re-circulation near the baffles, optimal mass flow rate, the optimal baffles position and percentage of baffles cut for the given heat exchanger geometry are determined from simulation. The simulation results show that staggered tube arrangement with eight number of baffles (30% BC) case has a comparatively good result to other cases. The numerical analysis is carried out by ANSYS 16.2 package CFX.