No abstract

Solar desalination is known as a method used to turn brackish into potable water owing to high population density and automation, consumable water demand continues to increase. and the system used for desalination is known as a solar still. The main types of solar stills include active and passive solar stills fresh water is obtained from passive solar stills without the use of high-grade energy(electrical energy). several researchers framed mathematical expressions, performed experiments, and confirmed the outcome of the different types of solar stills This paper analyzed the methodologies used in previous years to enhance the efficiency of active and passive solar stills. using types of absorbent materials, reflectors, and a sun tracking device is introduced the solar energy intensity is maximum and thus improves absorption production by 380%, an overall increase in efficiency of 2% will increase production to around 22% in some research, Through this study, The results showed that the use of wire nets and sand in the container increases the daily output of freshwater by about 3.1%, 13.7% in winter, about 3.4% and 14.1% in summer. It also turns out that the productivity of distillation is 20 L / m 2 over the inverter compared to 5 kg / m 2 in the conventional system. Results also show that the efficiency of the solar still is affected by the kinds, design, and heat storage system.

This study investigated the production of single slope solar still and the influence of combining with a parabolic trough collector. The effect of the different working fluid types on freshwater productivity, outlet working fluid temperature, heat gain, and thermal efficiency has been studied under the weather conditions of south city of Iraq/ Najaf (32° 1' N / 44° 1' E). The first type was water and the second type is nanofluid. The results of the comparison showed when using water as a working fluid flowing inside the receiving tube for different days; the highest temperatures were obtained at 12:00 pm, and the average productivity of distilled water was obtained in May and June 2021 were 4.5358 and 6.733 kg/m2/day respectively. While when using the nanofluid as a working fluid flowing inside the Parabolic Trough Collector (PTC) receiver tube, the outlet temperatures were rising for the same comparison days with an increase in the productivity of distilled water. Where the freshwater productivity during the day was 8.745328 kg /m2 /day as, and it was 9.018119 kg/m2/day during the other day. A productivity analysis was carried out for two different working fluid types (Water and nanofluid instead of water) as a fluid running inside the receiving tube of PTC. The freshwater produced from PTC (with nanofluid) was a 42.2% improvement in productivity compared with conventional PTC.