Optimization of solar desalination integrated with thermal energy storage using phase-change material

Desalination of the brackish water using a passive solar still with a Phase change materials (PCMs) put under the basin liner of the distillation device is dealt with the help of transient mathematical models. To achieve an optimal system, genetic algorithm is used. In order to estimate the desalinated water in a year, the mass of fresh water in two days of midsummer (7 August) and the midwinter (4 February) was calculated as the typical days in summer and winter. It is assumed that the average amount of water produced in these two days will be repeated for all days at the year. The results showed that mass reduction of saline water is lead to Increase of desalinated water mass. A salt hydrate PCM that its thermal conductivity and density were 0.69 ୵௠.௄ and 1505 ୏୥௠య respectively was selected as the optimal PCM. This type of PCM had a higher thermal conductivity and density than other PCMs. The melting point of this type of PCM is 58°C, which is close to the maximum temperature that saline water reaches in the summer. According to considered limitations for inputs of genetic algorithms, water mass, PCM mass and thickness of the glass, 20 kg, 3.14 kg and 2.15 mm were selected respectively. The maximum amount of annual produced freshwater In optimal mode obtained 1632 kg per square meter of desalination.