Investigation of performance and entropy generation rate of Direct Contact Membrane Distillation (DCMD) with Static Mixer (SM): 3D CFD study

This study investigated the performance of Direct Contact Membrane Distillation (DCMD) with a Static Mixer (DCMDSM) and compared it to conventional DCMD using 3D Computational Fluid Dynamics (CFD) under steady-state conditions. The permeate flux and total entropy generation rate (TEGR) were explored as functions of various parameters, including temperature differences between feed and permeate flow, inlet velocity, salt mass fraction, membrane porosity, membrane thermal conductivity, and membrane pore radius. The study revealed that the maximum permeate flux of DCMDSM was 79% higher than DCMD. Additionally, the average TEGR of DCMDSM was 67 % lower than that of DCMD. Furthermore, increasing the inlet velocity led to higher permeate flux in both DCMD and DCMDSM. The results showed that the performance of the DCMDSM at lower velocities was better than at higher inlet velocities. Moreover, increasing the temperature difference between feed and permeate, salt mole fraction, and porosity showed similar effects on permeate flux for both DCMD and DCMDSM, with the permeate flux of DCMDSM consistently exhibiting 60% higher permeate flux than DCMD across all parameter ranges. Finally, the analysis of membrane thermal conductivity indicated that higher thermal conductivity of the membrane resulted in better permeate flux for DCMDSM than DCMD. Additionally, the TEGR analysis revealed that it was minimized at lower temperature differences, higher inlet velocities, and lower membrane thermal conductivities for both DCMD and DCMDSM.