## 4 Discussion and Results
### Parametric Studies Results  
Figure 5 illustrates the impact of the compressor pressure ratio PR on the developed performance of the system, cost, and carbon footprint. The findings show that the network output decreases while \(\eta_{\text{th}}\) and \(\eta_{\text{ex}}\) efficiencies increase with higher pressure ratios. This proposes a trade-off between efficiency gains and the amount of work that can be extracted. Higher pressure ratios demand more energy from the compressors, leading to decreased power generation from the bottoming cycle BC. Additionally, an increase in the PR negatively affects the Rankine cycle's RC power output. This occurs because a higher PR reduces the gas turbine's exhaust temperature, diminishing the energy available for the RC cycle. Consequently, the RC's mass flow rate decreases, reducing power generation. According to Figure 4, increasing the PR from 6 to 15 reduces the system's total \(\text{W}_{\text{net}}\) output  
Figure 4: Flow chart of total cost rate, exergy cost, and \(\text{Ex}_{\text{dest}}\) rate of the proposed hybrid system. from 245.3 MW to 201.1 MW. The analysis reveals that an increase in the BC pressure ratio leads to a concomitant decrease in both the total \(\dot{\mathrm{W}}_{\mathrm{net}}\) and the fuel consumption of the cycle. The decline in fuel consumption is demonstrably more significant than the reduction in \(\dot{\mathrm{W}}_{\mathrm{net}}\). It translates to lower energy and exergy inputs into the system, ultimately enhancing overall efficiencies for the combined cycle. As depicted in the figure, \(\eta_{\mathrm{th}}\) rises with the PR, starting at 57.89% for a compressor pressure ratio of 6 and rising to 62.38% at a compressor pressure ratio of 15. Similarly, the exergy efficiency also improves with the pressure ratio, from 55.9% at a compressor pressure ratio of 6 to 60.23% at a PR of 15. The energy cost decreased as the PR increased, reaching a minimum point before rising at higher pressure ratios. The data indicated that the optimal pressure ratio was 8 bars, corresponding to the lowest energy cost of USD 71.93/MWh. This subsequent increase in cost is attributed to the higher expenses of BC component materials associated with a higher compressor pressure ratio. Furthermore, the decline in fuel consumption associated with an increased PR also reduces the CO\({}_{2}\) mass flow rate at the exhaust, leading to lower CO\({}_{2}\) emissions. Reducing the carbon footprint with higher pressure ratios is a significant positive outcome, indicating that optimizing pressure ratios can contribute to more sustainable energy production. The carbon footprint decreases as the pressure ratio increases, from 340.8 kg CO\({}_{2}\)/MWh at a PR of 6 to 316.3 kg CO\({}_{2}\)/MWh at a compressor PR of 15. This demonstrates that higher pressure ratios result in lower greenhouse gas emissions per unit of energy generated. Figure 6 demonstrates the impact of the gas turbine inlet temperature (GTIT) on the developed system's performance, environmental footprint, and energy costs. The parametric study of the GTIT presumes constant efficiencies for both the turbine and compressor. In actuality, alterations in the gas turbine's operating point impact both efficiencies, diminishing the total performance advantages. Increasing the GTIT increases power production across the bottoming BC, RC, and Organic Rankine Cycles (ORCs). The rise in GTIT leads to higher exhaust temperatures from the GT, thereby increasing the energy available for the RC and ORCs to utilize. Consequently, this results in a higher mass flow rate in the RC and ORCs, enhancing their power-production capabilities and improving the efficiency and power output of the entire cycle. Figure 6 shows that the \(\dot{\mathrm{W}}_{\mathrm{net}}\) output substantially increases with the GTIT, rising from 150.6 MW at 1100 K to 339.7 MW at 1600 K. As the GTIT increases, the overall efficiencies of the developed system improve rather than decrease.