Simulation of a solar thermal membrane distillation: comparison between linear and helical fibers

In arid coastal regions, the lack of potable water coincides often with high solar insolation. In this case, coupling of the desalination systems with solar energy is of great importance. Among the desalination systems, the membrane distillation technique holds numerous advantages. The present work focuses on the vacuum membrane distillation coupled with solar energy. The aim is to simulate a novel membrane configuration in order to enhance the permeate product. This novel membrane is composed of hollow fiber wound in helically coiled shape. Two-dimensional Navier–Stokes equations are written and then solved using the finite element method. For a pitch of 32.2mm and a coil radius of 95.7 mm, the simulation results of the permeate product are 0.2685 kg/h and 7.688 10−3 kg/sm² for the permeate flux. These values present an enhancement when compared to the linear hollow fiber configuration at the same operating conditions. This enhancement is about 28% for the permeate flow rate.