Heat loss reduction techniques for walls in solar stills: A review

Abstract

Every day, the number of places throughout the world where people can get access to safe water is decreasing. Contaminated or improperly distilled water sources are the root of a number of diseases. Hence, there is an urgent need for people to have an environmentally friendly way to purify water. Solar distillation is an exceptional clean water treatment technology. Another method of water purification that yields potable water is the solar still (SS) technique. However, the solar still layout has to be enhanced due to a number of operational and atmospheric factors. It is well known that as solar radiation strikes the vertical sides of the SS, it become hotter, and the high temperature area causes significant energy losses to the surroundings. Researchers have looked into a number of methods to enhance the yield of solar stills. This paper provide an in-depth analysis of the current state of the various methods used to reduce losses of back wall of SS, for instance, drum, vertical wick, rotating wick, discs, trays, copper heaters …. etc. Diverse results (increase in productivity) demonstrated the importance of vertical wick (69–71%), internal trays (43–45%), internal reflectors (19.9–55.5%), and internal revolving discs (51–106%). As a result of this study, future researchers will be able to focus on creating strategies to reduce thermal losses in SS walls. This paper also discusses the already explored parameters of the setup and highlights the associated concerns. Research on SS is currently ongoing, and proposals for other research initiatives have been put forth in light of this study's findings.

Keywords

• Solar stills
• Heat loss in solar still
• Copper heating coil
• Rotating parts
• Nanoparticles
• Wick solar still