Water desalination by evacuated tube heat pipe solar collector

This paper presents preliminary results that were obtained while monitoring the thermal performance of a solar water desalination system. The system consists of a solar collector equipped with evacuated heat pipes which supply the heat from the sun to a circulating fluid in a collective manifold. Data was obtained indoors by the use of a solar simulator during experiments conducted in the Department of Mechanical Engineering at Cape Peninsula University of Technology (CPUT). A solar simulator consisting of an array of halogen Flood lights was used to heat the evacuated heat pipes which in turn transferred the heat to the circulating fluid feeding a heat exchanger in the system´s geyser. The irradiance from the solar simulator that could be controlled by means of variable transformers controlling the voltage to the halogen lamps was measured over the surface of the evacuated heat pipe collector. The procedure allowed for exposure of the collector to the solar simulator for seven hours daily and thereafter normal cooling of the system. Preliminary results so far have shown that it is possible to use modern domestic water heating systems to produce steam which when condensed becomes potable water.