Thermal behavior calculation and analysis of submerged combustion LNG vaporizer

Abstract

Submerged combustion vaporizer (SCV) is widely equipped in liquefied natural gas (LNG) gasification plants and receiving terminals as the emergency or peaking regasification facility. This paper constructs an energy balance-based numerical model to predict the thermal behavior of SCV operating at subcritical pressures. The heat transfer coupling between the ice formation at the water bath-side and the flow boiling at the LNG-side is considered in the numerical model for the first time, and numerous correlations are utilized to estimate the convective heat transfer rate at both the water bath and LNG sides. The thermal behavior of a typical SCV in the presence of ice layer is studied numerically after validating against the field operating data. The predicted results indicate that the SCV can vaporize cryogenic LNG to a near-normal atmospheric temperature under low water bath temperatures, although an ice layer, having negative effects on heat transfer, is formed on the lower part of the heat transfer tube. Both the operating parameters and heat transfer enhancement measures have significant impacts on the thermal behavior.