Performance of dual multistage flashing - recycled brine and solar power plant, in the framework of the water-energy nexus

Abstract

Water is an essential source for life, and due to rapid growth in the population, the demand for clean water is increasing, while the freshwater reservoirs and aquifers are continuously depleting, creating water scarcity. By using desalination techniques, ocean water can be converted into useable water. In this study, a Multistage flashing- Brine recirculation (MSF-BR) model is used as a technique to produce desalinated water. A mathematical model is developed to investigate the performance ratio of the MSF plant driven by solar energy by using a poly PV array type. This solar power plant can provide 6.52 kg/s superheated steam for the system of thermal desalination. The solar power plant is made up of 72 poly-Si panels with 34 strings each. This facility has a capacity of 30 MW; 15 MW is utilized to produce 6.52 kg/s of superheated steam, which is used to power the MSF-BR desalination plant, while the rest is fed into the grid. The MSF-BR plant is made up of twenty-four stages, twenty-one of which are in the heat recovery section (HRS) and the remaining three in the heat rejection section, which is designed to be the most efficient. The top brine temperature is 110 C, the distilled water is 63.314 k/s, and the blowdown brine salinity concentration is around 69,439.54 ppm, according to the MSF-BR performance. Also, with a heat transfer area of 14,559.8 m2 for HRS and 1,663.8 m2 for the rejection section and a stage length of 1.37 to 2.648 m from the first to the last stage, the optimum gain was achieved.