Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman Thermal analysis of a hybrid solar desalination system using various shapes of cavity receiver: Cubical, cylindrical, and hemispherical Alireza Rafiei a , Ali Sulaiman Alsagri b, ⁎ , Shuhaimi Mahadzir a,e, ⁎ , Reyhaneh Loni c , Gholamhassan Najafi c , Alibakhsh Kasaeian d a Process Design Development Research Group, Center for Process Systems Engineering, Institute of Autonomous Systems, Universiti Teknologi PETRONAS, Seri Iskandar, Perak, Malaysia b Mechanical Engineering Department, College of Engineering - Unaizah, Qassim University, Saudi Arabia c Department of Biosystem Engineering, Tarbiat Modares University, Tehran, Iran d Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran e Chemical Engineering Department, Universiti Teknologi PETRONAS, Seri Iskandar, Perak, Malaysia ARTICLE INFO Keywords: Solar hybrid desalination Focal point concentrator Cavity receiver Photovoltaic Humidification dehumidification ABSTRACT In this research paper, a hybrid solar desalination system has been employed. The hybrid solar desalination system includes photovoltaic thermal panels, solar dish concentrator, and humidification-dehumidification de- salination unit. The humidification-dehumidification desalination unit comprises a closed-air open-water flow configuration, and the solar dish concentrators are utilized for water heating. Examination of three different shapes of cavity receiver including cylindrical, cubical and hemispherical, as the solar dish absorbers, was carried out. Thermal oil was considered as the solar working fluid. The absorbed solar heat was transferred to the desalination unit using a heat exchanger. In the hybrid solar desalination, photovoltaic panels were used to generate the required power. Water flow was considered at the back of the photovoltaic panels for preheating and improving the photovoltaic efficiency. The principal aim of the current study is to propose hybrid solar desalination system to generate power, and produce freshwater. The solar desalination's performance was ex- amined in terms of various solar dish parameters and different humidification-dehumidification desalination parameters. Examination of various solar dish parameters, including the solar working fluid's inlet temperature and the cavity shapes, was carried out. Also, some humidification-dehumidification desalination parameters, including the water to air flow ratio and the water flow rate, were considered. The effects of these four para- meters were investigated on the water production and the gain output ratio. Based on the results, it was found that there was an increase in the production of freshwater by raising the water flow rate, decreasing the solar working fluid inlet temperature and increasing the air flow rate. Besides, there was an increase in the gain output ratio by increasing the water flow rate, increasing the inlet temperature, and increasing the air flow rate. Finally, the highest freshwater production and lowest gain output ratio were resulted by the hemispherical cavity re- ceiver. 1. Introduction Based on the global environmental and developmental plan for sustainability, water and energy are two critical resources, since both are inseparably linked to each other. Power could be harnessed from water to perform processes like extracting, cooling, and refining. Likewise, extraction of water is done by making use of energy in pro- cesses such as capturing, pumping and treating of wastewater, dis- tribution of water, and desalination. Thus, there is an interconnection between energy and water on a global scale. A deficiency or development in any one of the two sectors could cast indirect or direct impacts on the other one, as well as on the economic development of societies. Moreover, considering the alarm by global climate change, it has become crucial to effectively use renewable sources to produce energy without damaging the environment further [1]. There are different kinds of renewable energies such as wind, solar, biomass, etc [2]. Though it has been forecasted that the issue of water scarcity will likely grow further in majority of the countries by 2025, it is also important to note that there is abundant solar energy available worldwide [3]. Thus, https://doi.org/10.1016/j.enconman.2019.111861 Received 14 November 2018; Received in revised form 18 July 2019; Accepted 19 July 2019 ⁎ Corresponding authors. E-mail addresses: a.alsagri@qu.edu.sa (A.S. Alsagri), shuham@utp.edu.my (S. Mahadzir). Energy Conversion and Management 198 (2019) 111861 0196-8904/ © 2019 Published by Elsevier Ltd. T