Design and Analysis of Open Rack LNG Vaporizer

Abstract

The dominating LNG Vaporizer is the Open Rack Vaporizer, which uses seawater for the heat source. This Vaporizer is designed to exchange heat between LNG of −160°C and seawater of ambient temperature, thus resulting in phenomena such as the vaporization of LNG inside heat exchanger tubes and the icing of seawater on the external surface of the heat exchanger tubes, which brings about difficulties in the thermal design. Since the ORV is the heat exchanger that makes a significant difference in temperature and needs a rapid startup or shutdown, appropriate considerations should be given to thermal stress. In this connection, through a variety of tests or analysis by the finite element method, highly endurable structures have been established. The thermal design method making it possible to design best-suited shapes (e.g. sizes and internal/external surface shapes) of the heat exchanger tubes through the use of numerical analysis and the thermal stress design of ORV is introduced hereunder.