## 4 Discussion and Results
### Parametric Studies Results
This improvement results from a concurrent increase in the cycle's overall \(\dot{\mathrm{W}}_{\mathrm{net}}\) and fuel consumption, which occurs at higher GTIT levels. The increased fuel consumption leads to more energy and exergy inputs into the system, which are compensated by the enhanced total power output, thus raising the system's overall  
Figure 5: The effect of the compressor pressure ratio (PR) on the developed system’s environment, performance, and cost. efficiencies. The results show that thermal efficiency experiences minor variations as the GTTT increases. It starts at 59.99% when the temperature is 1100 K and peaks at 60.65% when it reaches 1450 K. Beyond this, it stabilizes at around 60.5% as the temperature rises to 1600 K. The exergy efficiency remains relatively stable throughout the temperature range, fluctuating slightly between 57.93% at 1100 K and 58.47% at 1600 K. The findings illustrate that higher GTTIs enhance thermal efficiency and significantly boost work output, which can lead to lower costs up to a specific temperature--in this case, 1400 K. Beyond this temperature, the costs increase slightly. The figure shows that energy costs initially drop from 97.76 USD/MWh at 1100 K to USD 70.29/MWh at 1400 K, then stabilize and rise again, reaching 81.02 USD/MWh at 1600 K. The lowest cost corresponds to the peak in thermal efficiency. The optimal range for cost efficiency is identified between 1400 K and 1450 K, where energy costs are minimized and thermal efficiency is maximized. Furthermore, although the CO2 mass flow rate at the exhaust increases with higher GTTI values, the carbon footprint remains relatively stable, showing minimal variation despite changes in GTTI. This stability is credited to the increased total power output facilitated by the higher GTTI, compensating for the rise in the CO2 mass flow rate. As a result, the carbon footprint stays relatively constant, around 326 kg CO2/MWh, across most temperature settings, with only a slight increase to 329.5 kg CO2/MWh as the temperature reaches 1600 K.  
Figure 7 evaluates how the input temperature T1 of the HPST affects the developed system's performance, environmental effect, and cost indicators. While the bottoming cycle's power output remains constant, the Rankine cycle's power output decreases as T1 is reduced. This decline is attributed to the lower T1, which minimizes the enthalpy of the working fluid at the HPST inlet, resulting in less energy available for the RC cycle to utilize and consequently leading to a decrease in both the \(\dot{\mathrm{W}}_{\mathrm{net}}\) and efficiencies of the developed system. The net power output exhibits a downward trend with a reduction in temperature, falling from 241.6 MW at 813 K to 235.5 MW at 723 K. This trend is in line with the decreases in both \(\eta_{\mathrm{th}}\) and \(\eta_{\mathrm{Ex}}\) efficiencies, suggesting reduced energy conversion into work as temperatures decline. \(\eta_{\mathrm{th}}\) generally decreases, starting at 60.47% and dropping to 58.95%, and \(\eta_{\mathrm{Ex}}\) decreases from 58.39% at 813 K to 56.92% at 723 K. The findings also depicted that increasing the HPST inlet temperature has a positive impact on the system's economic performance and environmental impact. Reduced temperatures lead to lower efficiency and somewhat increased energy expenses, emphasizing the need to sustain higher temperatures for economically efficient operation. As the temperature falls, there is a slight rise in energy costs. The cost per (MWh) rises from 70.29 USD/MWh at a temperature of 813 K to 72.59 USD/MWh at a temperature of 723 K. The correlation between lower temperatures  
Figure 6: The influence of the temperature of the GTTI on the developed system’s performance, environment, and cost. and an increased carbon footprint highlights the negative environmental impact of diminished efficiency. This suggests that higher operating temperatures not only improve performance but also help to minimize carbon emissions.