International Conference on Advances in Science and Arts Istanbul 2017, İstanbul, Turkey, 29 March 2017, pp.1
At the present time, over a billion people lack access to clean drinking water. With the worldwide industrialization and global warming, even the sources we have today are at a risk of contamination in the future. In this respect, membrane distillation (MD) is a viable solution to obtain potable water. It is, however, criticized because of its higher energy demand. In this work, we focus on this problem and offer a portable membrane distillation unit that is connected to a parabolic solar collector which provides the needed energy for heating of water to the desired temperature. This approach minimizes the cost of energy consumption, as solar energy is one of the most accessible energy forms around the world.
MD unit requires an inlet temperature in the range of 60-70 C; therefore, it is crucial to control the output temperature of water leaving the parabolic solar collector. The atmospheric temperature, solar irradiance, wind velocity and flow rate of water flowing through the solar collector are the variables in this matter. To this end, we use COMSOL Multiphysics® to characterize the proposed system. In this paper, we used this platform to obtain simulations of heating of water flowing through 3.4 cm inside, 4 cm outside diametered copper pipe located at the focus of a parabolic solar collector which can increase the solar irradiance tenfold (10x solar irradiance). By changing the variables we observed the output temperature of water. With the data collected from the simulations, we used central–composite design to obtain a model for the system.We also studied the energy balance of the collector and obtained a relation for efficiency in terms of our variables, which results in reasonable values for the system.