Nader Frikha

Simulation of an autonomous solar vacuum membrane distillation for seawater desalination

AbstractSeveral papers deal with membrane distillation of seawater and mainly focus on the choice of membranes and comparison of this technique with other desalination techniques, but there are very few studies that quantitatively estimate the potential of this technology coupled with solar energy. The objective of this work is to develop a model describing the operation of a desalination membrane powered by solar energy. This model determines the performance of the unit over time and for any day of the year. This model is established from the balance equations of mass and heat on the different units (membrane, exchanger, condenser, and field of solar collectors). The model is used to evaluate the evolution of the distillate flow rate and temperature changes for different flows. The model also allows to estimate the productivity of the unit during the year. The simulation of the operation of the unit shows that the daily production of distilled water is between 63 and 188 kg/m2 for the days of 21 December...

Study of the performances of different configurations of seawater desalination with a solar membrane distillation

AbstractThe object of this study is the comparison between two configurations of hollow fiber module for seawater vacuum membrane distillation. The first one is a module membrane in series with a solar compound parabolic collector (CPC). The second configuration is a hollow fiber module integrated in a cylindrical absorber of CPC. A model describing the operation of a hollow fiber module, with and without recycling, will be developed. This model determines the instantaneous variation of the temperature of each element of the installation with the distillate flow variation. A comparison of each module production is carried out. A mathematical model describing the performances of different configurations for membrane hollow fibers shows that: (1) The permeate flow for the integrated configuration is always higher than that of not integrated. It can be multiplied by two and even more. (2) The recycling of concentrate makes it possible to improve the production. This is due to the high level temperature at th...

Numerical Investigations of Coupling a Vacuum Membrane DesalinationSystem with a Salt Gradient Solar Pond

This work proposes new configurations for the desalination of salt water using systems based on coupling of membrane distillation with solar energy. This study is a comparison between two coupling configurations of the vacuum membrane distillation (VMD) hollow fiber module with salinity gradient solar pond (SGSP). The first configuration is a module membrane in series with SGSP and the second one is a hollow fiber module immersed in the SGSP. Two models describing the heat and mass transfer in the hollow fiber module and in the SGSP will be developed. The coupling of the two models allows the determination of the instantaneous variation of temperature and salinity in the SGSP and the permeate flow variation. A comparison of each module production was carried out. The mathematical model shows that the immersed module production presents more than one and a half times that of the separated module, their production reached 75 kg.day-1 per m² of the membrane in the third year. Thus, immersing the module in the solar pond improves the performance of the hollow fiber module.