Impact of shipborne conditions on liquid oxygen distillation efficiency in a compact S-type sieve tray column

Cryogenic distillation for oxygen production in ships faces challenges from tilting and oscillation, disrupting vapor–liquid phase distribution and heat/mass transfer, leading to reduced performance and purity. This study proposes a sieve tray column with an S-type high-efficiency heat exchange structure and uses numerical modeling to analyze two-phase flow under normal and tilting-oscillation conditions. Results show that higher liquid mass flow rates suppress temperature rise, reducing heat and mass transfer efficiency. Tilting in transverse and longitudinal directions causes fluid maldistribution, significantly lowering tray performance, with greater impacts at larger tilting angles. Oscillation also adversely affects distillation, but fluid inertia during shorter oscillation periods (6 s) mitigates maldistribution, improving efficiency for tilting angles of 1.5°∼5°. However, at higher oscillation angles (10°∼15°), an 8 s oscillation period provides better efficiency due to increased maldistribution. These findings highlight key design considerations for ship-based cryogenic distillation systems.