The effect of magnetic field on the performance improvement of a conventional solar still: a numerical study.

Abstract

Due to growing demand for potable water, the improvement of fresh water production systems such as conventional solar stills is a crucial issue. Conventional solar stills are one of the simplest methods of the production of fresh water from saline water; however, they are fairly low-performance devices. Since oxygen is a paramagnetic gas, the humid airflow in a conventional solar still can be controlled by an externally imposed magnetic field. Therefore, this paper presents the effect of magnetic field on the performance improvement of a conventional solar still as a novel technique. The governing equations of the problem are discretized by the finite volume method. The impacts of the applied magnetic field arising from a multilayer solenoid on the streamlines patterns, temperature and mass fraction contours, the production rate of water ([Formula: see text]), and the average heat transfer rate (Nu) are presented at five specified times (cases). The influences of important factors such as intensity (0≤NI≤100000) and location of the magnetic field (Xc=0.15, 0.49, and 0.83) on the heat and mass transfer rates are explored. It is found that the production rate of water and heat transfer rate are increasing functions of magnetic field intensity. For the applied magnetic field with NI = 105and Xc = 0.83m, water productivity and convective heat transfer rate can be increased by about 43%, 38%, 41%, 40%, and 48% for cases 1, 2, 3, 4, and 5, respectively.