Abstract
•The heat and mass transfer in a solar still embedded with PCM is studied.•The Finite volume method is used to solve the governing equations.•An external water stream is used to enhance the heat and mass transfer.•The effects of the buoyancy ratio and the Rayleigh number have been investigated.
The increase demand of water for irrigation and human activities leads to a global development of alternative methods to produce distillate water especially from sea. In this context, the use of solar distiller instead of the classic distillation process is a good solution to preserve environment and reduce the use of fuel. This study explores the advantages of the classic solar still by studying the effect of the PCM-RT42. Hence, a detailed investigation of the heat and mass transfer of a single slope solar still incorporation PCM-RT42 as heat storage system will be presented.
The governing equations are solved numerically with employing the finite volume method. The next scopes of parameters are utilized in the computations: dimensionless time (τ = 4.2×10–3, 25.2×10–3, and 50.4×10–3), Rayleigh number (104 ≤ Ra ≤ 106), buoyancy ratio (1 ≤ N ≤ 5). Mixture Prandtl number (Prm), Schmidt number (Sc) and Lewis number (Le) are presumed as fixed to 0.705, 0.613 and 0.869, respectively.
The results show the good effect of the PCM-RT42 on the transfer of heat and mass compared to the initial time for low Ra. However, for Ra=105 and 106, a reduction in the efficiency of condensation and the performance of the solar distiller is observed.
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