# Study of the Impact of PV-Thermal and Nanofluids on the Desalination Process by Flashing
## 7 Conclusions  
A novel concept was presented in this paper for the MSF process, that implements PV-Thermal solar panels using hot heat transfer fluid with nanofluids. A mathematical and numerical model to describe the PV-thermal solar to drive the multistage flashing chamber process was presented. The model proposed was established after the mass and energy conservation equations written using the finite control volume approach with integrated thermal and thermophysical properties of the water and nanofluids as heat transfer fluids. The nanofluids under investigation are Ai\({}_{2}\)O\({}_{3}\), CuO, Fe\({}_{3}\)O\({}_{4}\) and SiO\({}_{2}\). The flashing process was studied under various conditions, including different solar radiations, brine concentrations and nanofluids volumetric concentrations, as well as different flashing chamber temperatures and pressures. Solar radiations were taken as 500 w/m\({}^{2}\), 750 w/m\({}^{2}\), 1000 w/m\({}^{2}\) and finally, 1200 w/m\({}^{2}\). The nanofluids volumetric concentrations considered varied from 1% through 20%. There was clear evidence that the higher the solar radiation, the higher the flashed flow produced. The results also clearly show that the irreversibility was reduced by using nanofluid Ai\({}_{2}\)O\({}_{3}\) at higher concentration of 10% to 20% compared to water as base heat transfer fluid. It was found that the highest irreversibility was experienced when water was used as the base fluid and the lowest irreversibility was associated with nanofluid SiO\({}_{2}\). The irreversibility increase depended on the type of nanofluid and their thermodynamic properties. Furthermore, the higher the concentration of Ai\({}_{2}\)O\({}_{3}\); 10% to 20%, the higher the availability at the last flashing chamber. However, the availability was progressively reduced along the flashing chambers and was evident at the last flashing chamber. It was observed that the nanofluid SiO\({}_{2}\) has the highest availability among the other nanofluids and water as the base fluid across the flashing chambers. The results presented in this paper demonstrate that it is possible to increase the preheating process quality through the increase of the flashing chamber temperatures which, in turn, improves the plant thermal efficiency. The present study demonstrates an added value to the research in the thermal desalination by the use of solar energy, solar PV-Thermal panels as the driving force to the evaporation flashing process instead of a steam boiler. This approach represents a step forward towards the sustainability and reduction of global warming effects. The predicted results were compared to the experimental data published in the literature. The comparison showed that the model fairly predicted the data under consideration. Finally, we  
Figure 25: Comparison between model prediction and data [7]. * _[PERSON] (2017)_ _[PERSON] Computational modelling of thermofluidic flashing in MSF desalination. Ph.D. Thesis, The National University of Ireland, Galway, Ireland, 2017._
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