An Experimental Work on the Performance of Single Solar Still with Parabolic Trough Collector in Hot Climate Conditions Hawraa Fadhel 1* , Qahtan A. Abed 2 , Dhafer M. Hachim 1 1 Department of Technical Power Mechanics, Technical Engineering College / Najaf, Al-Furat Al-Awsat Technical University (ATU), Najaf 54001, Iraq 2 Technical Institute / Al-Rumaitha, Al-Furat Al-Awsat Technical University (ATU), Najaf 66002, Iraq Corresponding Author Email: hawraa.fadhel@student.atu.edu.iq https://doi.org/10.18280/ijht.390526 ABSTRACT Received: 27 August 2021 Accepted: 25 October 2021 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/m 2 /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 /m 2 /day as, and it was 9.018119 kg/m 2 /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. Keywords: solar distillation, productivity, parabolic trough collector, single slope solar still 1. INTRODUCTION Water is an essential component of human nutrition; the amount of pure potable water consumed each day for cooking and other family activities are between 20 and 50 Liters of clean potable water. The drinking water (freshwater) is a significant concern in many parts of the world, regardless of whether they are developed or developing countries, due to a lack of clean water. Imposing wastewater treatment methods from various sources to make it potable can help to solve the problem of pure water supply to a large extent. To clean the contaminated water, a number of technologies are available. The evaporation method using a solar still is one of the oldest and easiest ways to do so. To work, this technique simply requires sunlight and a small amount of manpower. As a result, it may appeal to both developing and emerging countries [1]. Fathy et al. [2] investigated the performance of a double-slope solar still with a parabolic trough complex (PTC) connection. The oil tubes connected to the PTC convert the solar energy that has fallen on it to solar energy. The solar stator contains an annular heat exchanger with finned tubes. Freshwater yields of 8.53 and 4.03 kg/m 2 /day are still linked to consistent PTC in two seasons (summer and winter). Hassan et al. [3] Using a parabolic trough collector, the effect of a middle made of salt water on the work of dual-action solar energy has been studied experimentally. Steel wire mesh, transparent salt water, and sand impregnated with salt water were used in the bowl as salt water media. The introduction of wire nets and sand increased daily fresh water output by about 3.1%, and by 13.7% in in winter, nearly 3.4% and 14.1% in summer. Al-Shamkhee et al. [4] The performance of pre-designed and produced water systems was investigated in an experimental study. For the first time, a wastewater desalination project was implemented at Najaf, Iraq (32° 1'N / 44° 1' E). The proposed design attempts to increase distilled water output by including a parabolic solar basin. The first outcomes, the primary results show an 11% increase in system efficiency, and the results also show that orienting the PTC to the north or south is optimum for preserving system efficiency. Riffat et al. [5] The performance of a V-shaped solar concentrator has been explored for water desalination applications. They claimed that the v-trough solar concentrator is a superior approach for small and medium-scale water desalination, with a 38% efficiency at 100℃ transfer fluid temperature at the concentrator output. Hassan et al. [6] The influence of brine middle and capacitor type on single slope solar energy work was studied experimentally. A typical solar stator fitted with a glass condenser and a still solar fitted with a flipper coated heat sink condenser are both tested. The use of a wire reticulum condenser, as well as a heat distributed and sand condenser, increased the freshwater output. Madiouli et al. [1] have experimentally examined the effect of combining a flat plate collector and running a standard sloped solar still. In addition to the parabolic trough complex supported by a spherical layer filled with glass, which works as a heat storage mechanism for the system. The results indicate that solar intensity combined with a parabolic trough collector can lead to excellent results. Morad et al. [7] the heat transfer and energy balance International Journal of Heat and Technology Vol. 39, No. 5, October, 2021, pp. 1627-1633 Journal homepage: http://iieta.org/journals/ijht 1627