Computational fluid dynamics simulations of desalination processes in vacuum membrane distillation

This study utilized computational fluid dynamics (CFD) simulations to investigate the impact of operational variables on the performance of a two-dimensional Vacuum Membrane Distillation (VMD) module. The analysis focused on various feed flow rates and temperatures. Within the feed channel, mixing promoters of three diameters (0.5 h, 0.3 h, and 0.1 h, where 'h' represents channel height) were employed to assess the effects of net-type spacers on reducing concentration and temperature polarizations while enhancing vapor flux. The findings revealed that higher feed water temperatures significantly increased vapor flux, concurrently reducing the temperature polarization coefficient (TPC) and raising the concentration polarization coefficient (CPC). This increase in vapor flux notably influenced CPC by exacerbating salt accumulation on the membrane surface. The incorporation of spacers consistently led to a decrease in both concentration and temperature polarizations throughout the module, with larger spacer diameters contributing to improved system performance. Notably, the use of spacers with a diameter of 0.5 h resulted in a 53 % increase in overall vapor flux. • Utilized CFDsimulations to investigate the impact of operational variables on the performance of a two-dimensional VMD module. • The analysis focused on various feed flow rates and temperatures. • Higher feed water temperatures significantly increased vapor flux, concurrently reducing the temperature polarization coefficient and raising the CPC. • The in vapor flux notably influenced CPC by exacerbating salt accumulation on the membrane surface. • The incorporation of spacers with a diameter of 0.5 h resulted in a 53 % increase in overall vapor flux.