PROBLEM Access to fresh and safe drinking water is a major challenge in many countries. A variety of solar desalination technologies exist, which range from passive to highly automated systems. The problem for third-world countries is that advanced technology is difficult to fund and to maintain. Hence passive designs are advantageous. Previous research by A. Gorrie concluded that using forced cooling of the external condenser surface, an increase in water production of 60% was observed [1].

NEED As identified, the need for keeping the external condenser surface cool is the most effective method of increasing water production, and therefore different geometric designs of the external condenser surface were looked at to enhance heat rejection from the condenser.

PURPOSE There is a need to design and optimize, build, and computationally model the heat rejection of a new condenser. This is to validate that the new design is capable of rejecting more heat than the current setup (flat plate condenser). The main variable in optimise was minimisation of material use, and manufacturing economics.

APPROACH The research project intends to (a) come up with several conceptual designs, (b) run CFD (Computational Fluid Dynamics) parametric optimisation, (c) build the optimized design candidate and collect empirical data, (d) build a transient CFD model of the optimized design, and (e) formulate a mathematical model describing the water production due to the new condenser design.

COMPLEXITY This is a complex project because of the number of parametric variables involved in the optimisation process and in the commissioning of the rig to validate the optimisation results.

ORIGINALITY The work makes several original contributions. First it provides a method to optimise the design of condensers, when there is little or no published literature in this area. Second, it provides a specific solution for a solar still, and has the potential to deployed.