The influence of swing movement on transient condensation thermo-fluidic performance for hydrocarbon mixture in a helical tube

To investigate transient condensation thermo-fluidic characteristics in helical pipes of spiral -wound heat exchangers tube -side under swing motions, a numerical model was established in consideration of sloshing effects, which validated by experiment data. The influences of swing movements (rolling and pitching motions) on flow patterns, transient pressure drop and heat transfer under varies swing and operating conditions were investigated and the overall performances at swing conditions were analyzed. The results indicate that the swing motions can cause pressure drop and heat transfer oscillations. The fluctuation amplitudes rise as the swing amplitude and saturation pressure increase, and the swing cycle, vapor quality and mass flow rate decrease. The effect of swing amplitude is more remarkable than that of swing cycle. Besides, the pitching motion has better drag reduction and heat transfer enhancement effects, with an average drag reduction of 8.41%. and an average heat transfer enhancement of 4.67%, respectively. The overall thermal performance in a helical tube is also improved by swing motions, with improvement of PEC at rolling showing 6.93% and pitching showing 7.88%. The findings of this study are helpful to better understand transient thermo-fluidic performances of hydrocarbons condensation in a helical tube under rotational motions, and provide some guidance for improving the efficiency and stability of spiral -wound heat exchangers used in floating liquid natural gas fields.