## 3 Results
Contrary to the previous conditions, Case 4 with TURB 2-related parameters and Cases 11 and 12 with condensers-related parameters have the highest net power values. The net power rate of Case 4 is 16% larger than that of Case 0. The value is equivalent roughly to 3 MW more electricity generation. For Cases 11 and 12 with condensers-related parameters, this is 15.8% and 14%, respectively. Here it may be concluded that the most important components requiring care during design and operation processes of the Sinem GPP are turbines and condensers. With the aim of maximizing exergy efficiency of the GPP system, the exergy destruction rates occuring from the components for optimization conditions (Cases 1-12) are illustrated in Figure 10. Looking at Figure 10,  
Figure 8: The change of system exergy efficiency according to optimization conditions. under all optimization conditions large fluctuations occur in the amounts of exergy destruction in the condensers. It can be reached that optimization conditions mainly affect condensers. Thus, in the real system the condensers have primary importance and require emergency improvement. Additionally, the result of optimization processes is showed that exergy destruction in condensers can be reduced due to their fluctuations. Figure 11 shows the exergy destruction rates of the system components for Case 0 (the real system) and Case 4 with TURB 2-related parameters as optimization conditions. It can be observed from Figure 11 that the exergy destruction rates for CON 1 and CON 2 in the real system are 3.65 MW and 4.34 MW while in the ABC optimization process, their values fall to 1.77 MW and 3.16 MW, respectively. In this way contrary to increased exergy destruction rate from pumps, recuperator and pre-heaters, there is a 44% and 41% improvement in the condensers (CON 1 and CON 2), respectively. Of the evaporators, VAP 2 causes more exergy destruction compared to VAP 1 on level I. It can be considered that the steep fall in temperature of the geofluid emerging from VAP 1 causes this situation. Again, in the GPP, the mass flow rate of the geofluid steam added to VAP 2 on level II is not sufficient. A comparison of exergy destruction rates of the system components for Case 0 and Case 12 as optimization conditions is presented in Figure 12. The results of this graphic are in accordance with the results of Figure 11. In Case 12 there is a reduction of 51.5% and 27% in ex  
Figure 10: According to the optimization conditions (Cases 1–12), the amount of exergy destruction that can occur in the components of the Sinem GPP to ensure maximum exergy efficiency in the system. Figure 9: The change of system net power production according to optimization conditions. of condensers CON 1 and CON 2. Due to the pump and recuperator on level I, the percentage fall in level I is greater than that in level II. In this case, PU 1 and PU 2 may be more affected by pressure falls due to pollution and blunting of CON 1 and CON 2. The exergy efficiencies of components in the Sinem GPP for all the optimization conditions (Cases 1-12) is given in Figure 13. From Figure 13, under all optimization conditions, the exergy efficiencies especially for the turbines TURB 1 and TURB 2 are similar because the isentropic efficiencies of the turbines were fixed. Thus the power generated from the plant remains constant. In this study the net power of the system has been taken into account as a useful exergy of the system. So this is assessed by subtracting the amount of electricity used to run fans and pumps in the condensers from the generated electricity. As can seen in Figure 13, the components with highest exergy efficiency are TURB 1 as 93%, VAP 1 as 92% and CON 1 as change in 74-94%. In addition, the exergy efficiency of TURB 2 is 83%. The exergy efficiencies obtained for the turbines are the same as those obtained in the real system. The component with lowest exergy efficiency is the recuperator RECUP with 52%, and 36-54% for the pump PU 1.