Computational fluid dynamics numerical simulation of vacuum membrane distillation for aqueous NaCl solution

Vacuum membrane distillation (VMD) was considered as the multiphase flow (liquid and gas phase) process inside the porous media, and the membrane module was simplified to the two-dimensional structure with a single membrane silk. The simulation has studied the mass transformation and heat transformation of VMD process in the porous media, in which aqueous NaCl solution was seemed as an incompressible and steady fluid. In the processes of mass transfer, heat transfer and phase transition, all particles were supposed in local thermodynamic balance. By means of FLUENT, one of the softwares about computational fluid dynamics (CFD), the numerical simulation of the two-dimensional model of VMD for aqueous NaCl solution was established under the steady state. The paper also calculated and analyzed the volume rate of vapor with different feed temperatures.

Research Highlights
► Two-dimensional geometry model of VMD for aqueous NaCl solution was established using GAMBIT.
► The module was simplified to a simple structure with a single membrane silk.
► Multiphase flow, mass and heat transformation and phase transition were considered.
► Permeate flux of VMD process increased with the increasing of flow and feed temperature.