# Study of the Impact of PV-Thermal and Nanofluids on the Desalination Process by Flashing
## 5 Discussion and Analysis
Furthermore, Figures 11 and 12 were constructed to demonstrate the benefits of using a high concentration of nanofluids Ai\({}_{2}\)O\({}_{3}\), CuO, SiO\({}_{2}\) and Fe\({}_{3}\)O\({}_{4}\) on the values of the salt % in the flashed flow exiting at each flashing chamber. It is quite evident from the data presented in these figures that the salt % was reduced at the last flashing chamber with the increase of the concentration of nanofluids. In particular, nanofluid SiO\({}_{2}\) showed the highest reduction of the salt % in the flashed flow exiting the last chamber. Figure 11: Salt % flashed flow at 1200 w/m\({}^{2}\). Figures 13 and 14 show that the salt percentage in the brine flow at 1200 w/m\({}^{2}\) was increased progressively across the chambers with the use of the nanofluids; however, the increase of the percentage of salt in the brine flow was slightly impacted by the concentration of the nanofluids. In addition, it appears from the results plotted in these figures that the salt percentage in the brine flow was independent of the type of nanofluids within the water as the base fluid. On the other hand, Figures 15 and 16 display the development of the flashed flow profile at the different flashing chambers. In general, the data in these figures show that the flashed flow was progressively reduced until reaching the lowest value at the last chamber. This is due to the increase of the heat of vaporization at lower saturation temperatures and therefore, less amount of vapor is extracted from brine. As expected, the data show that the higher the concentration of the nanofluid, the higher the amount of flashed flow produced. Further analysis of the data observed clearly demonstrates that the use of the nanofluid Ai\({}_{2}\)O\({}_{3}\) produced the highest amount of flashed flow during this process. Figure 4:0 Salt % brine at 1200 w/m\({}^{2}\). Figure 4:1 Flashed flow (kg/s) at 1200 w/m\({}^{2}\) and 10% concentration. In order to study the influence of the solar radiation on the flashed flow, Figures 17 and 18 are presented. There is clear evidence that the higher the solar radiation, the higher the flashed flow produced. This is clearly demonstrated at both concentrations of the nanofluids in the figures. Moreover, these figures show that nanofluid Ai\({}_{2}\)O\({}_{3}\) produced the highest flashed flow among the nanofluids under investigation and water as the base heat transfer fluid. This observation is significant since using the nanofluid Ai\({}_{2}\)O\({}_{3}\) can enhance the production of flashed flow three to four times over the water as the base fluid. Figure 4:2 Flashed flow (kg/s) at 1200 w/m\({}^{2}\) and 20% concentration. Figure 4:3 Flashed flow (kg/s) at 10% volumetric concentration. Figures 19-22 explain the impact of the increase of the concentrations of nanofluids on the irreversibility and availability of the desalination flashing process, chamber by chamber at 1200 w/m\({}^{2}\) solar radiation. Analyzing the results presented in these figures clearly shows that the irreversibility calculated by Equation (16) was significantly influenced by the type of nanofluids used compared to the base water as the heat transfer fluid. In addition, as expected the irreversibility increased progressively across the different chambers until reaching the maximum at the last chamber. The highest irreversibility was experienced when water was used as base fluid and the lowest irreversibility was associated with nanofluid SiO\({}_{2}\). The irreversibility's increase depends upon the type of nanofluid and their thermodynamic properties. Moreover, it appears that the concentration of the nanofluid did not have a significant impact on the changes of irreversibility across the various chambers during the flashing process. Figure 4:4 Irreversibility (Btu/lb) at 1200 w/m\({}^{2}\) at 10% concentration and different nanofluids. Figure 4:5 Flashed flow (kg/s) at 20% volumetric concentration.