Experimental analysis of the condensation flow and heat transfer characteristic in a spiral tube under ocean swell conditions

The floating liquefied natural gas platform is a key enabling technology for the development of marine natural gas resources. It's core component, the spiral wound heat exchanger, is frequently subjected to offshore sloshing conditions, which present a significant challenge for the technology. To clarify the condensation flow and heat transfer characteristics in the spiral tube under offshore shaking conditions, an experimental system with a sloshing platform was constructed. The impact of sloshing mode (sway and roll), displacement (sway: 250∼1500 mm or roll: 3–15°), and period (10∼16s) on the heat transfer coefficient (h) and frictional pressure drop (ΔP_fric) were analyzed under different operational parameters (mass flux, vapor quality and pressure). Additionally, the comprehensive sloshing factor (CSF) was used to evaluate the overall effect of shaking on condensation process. The results show that the sway and roll motions positively impact the h and ΔP_fric. The impact decreases with the increases in mass flux and vapor quality and is negatively correlated with operating pressure. In sway motion, the CSF ranges from 1.39 % to 11.82 %, with an average of 5.15 %. In roll motion, the CSF ranges from 1.15 % to 5.13 %, with an average of 2.57 %.