Shell-side heat transfer characteristics of floating liquefied natural gas spiral wound heat exchanger under sloshing conditions

Abstract

To study the influence of offshore sloshing motion on the performance of a spiral wound heat exchanger (SWHE) installed on a floating liquefied natural gas (FLNG) platform and to explore potential methods to improve heat transfer efficiency, a sloshing experimental platform was established. This platform facilitated the experimental study of the boiling heat transfer process of a subcooled falling film on the outer surface of the heat exchanger tube. A quantitative analysis of the change in the heat transfer coefficient with respect to the amplitude and period of the rolling and swaying motion was performed. The experimental results indicated that both rolling and swaying changed the liquid film morphology, leading to a decrease in the heat transfer coefficient of the heat exchanger tube. The fluctuation in the heat transfer coefficient became more drastic with an increase in amplitude, but the effect of the swaying motion was less than that of the rolling motion. When the rolling angle was 12° and the Re number was 569, the average heat transfer coefficient of the round tube decreased by 55% compared with that at the static condition. Furthermore, the research encompassed the design, processing, and rigorous testing of elliptical and egg-shaped tubes to improve their heat transfer performance, and the results were compared with those of round tubes. Under the same rolling or swaying conditions, the heat transfer coefficients of the egg-shaped and elliptical tubes were 5.1–21.5% higher than that of the round tubes. The results of this study can be used as a reference for the operational and structural design of SWHEs under sloshing conditions.