Performance evaluation of a multi-stage solar distiller associated with Fresnel lens in Malaysian weather

Abstract

Water scarcity is widely known as one of the major current issues. As of now, many solar distillers are using the same concept of evaporation and condensation of saline water to produce distillates. The main problem with such solar distillers is their low productivity, as the latent heat produced is lost to the surroundings. A multi-stage solar distiller can solve the issue of productivity by utilizing the latent heat released. This design consists of multiple solar distillers stacked one on top of the another, producing distillates in each stage while having the same amount of energy intake. Malaysia falls within the tropical belt where solar radiation appears to be diffused, resulting in low-quality heat energy that can be absorbed. To solve this problem, concentrated solar power (CSP) technology has been introduced. However, CSP technology can be very expensive, thus using a Fresnel lens as a direct refraction device will be a cheaper option. In this study, a four-stage solar distiller system integrated with the Fresnel lens is introduced. It was found that the productivity and efficiency of the multi-stage system were higher, with a productivity of 0.164 g/kJ and efficiency of 39.5% when compared with the single-stage solar distiller with a productivity of 0.104 g/kJ and an efficiency of 23.5%.