טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentGaraway Isaac Jacob
SubjectInvestigation of a Solar-Powered Desalination System
Employing Regeneration
DepartmentDepartment of Mechanical Engineering
Supervisor Professor Emeritus Gershon Grossman


Abstract

The objective of this research project was to develop an optimized process that makes use of low-grade heat provided from solar irradiation to drive a distillation-desalination process.  An efficient distillation process re-uses input heat, by using the heat-of-condensation as the heat source for pre-heating the incoming cold saline water.  This research project was concerned with examining the physical and thermodynamic characteristics of this process so as to optimize the efficiency of a solar powered water distiller employing heat recovery.  The study was primarily concerned with understanding the natural convection driving the evaporation-condensation process and the other physical and geometric considerations that affect the distillation process.  In contrast to other projects investigating low temperature distillation devices employing regeneration, this research project incorporated a CFD (Computational Fluid Dynamics) analysis that formed the base for the optimization process.  By using such an analysis the optimum geometry for a distillation enclosure was determined to be an “ovalized rectangle”.  This basic geometry with CFD-optimized dimensions, along with some additional features was incorporated into a fully operational laboratory distillation system.  The distillation system was tested experimentally and its thermal efficiency was determined.  The device tested is capable of distilling water to levels of ~ 17 ppm dissolved salt content at thermal efficiencies comparable to the theoretical possible.  These findings, incorporated into solar distiller design will assist the designer in choosing optimized parameters to maximize the device’s efficiency.