## 3 Results
### ORC Evaporator Temperature  
In Figure 15, the results of the ORC evaporator temperature investigation are presented for geothermal heat source temperatures of 110 \({}^{\circ}\)C and 155 \({}^{\circ}\)C. The parametric analysis ranges from 50 \({}^{\circ}\)C to 130 \({}^{\circ}\)C for the ORC evaporator temperature. During the parametric analysis, the upper limit of the ORC evaporator temperature is set based on critical temperature of each working fluid to ensure subcritical operation. As shown in Figure 15, each working fluid has an optimal ORC evaporator temperature that maximizes net power. As the ORC evaporator temperature increases, the temperature difference between the geothermal heat source and the working fluid decreases, which reduces the heat transferred to the cycle. At the same time, higher evaporator temperatures lead to an increase in specific net work output (kj/kg). The overall trend in net power production is determined by the interaction between these two opposing effects. For most fluids, this results in an optimum point where further increases in evaporator temperature lead to reduced net power. This optimum point has also been reported by [PERSON] et al. [36] as an optimal turbine inlet temperature which corresponds to ORC evaporator pressure,  
Figure 14: Net power comparison of the proposed novel and reference cycle with condenser temperature variations. Figure 15: Power production of the proposed novel cycle with ORC evaporator temperature variations. and consequently its temperature based on the authors' definition of the turbine inlet as the ORC evaporator's outlet at saturated vapor phase. However, at the geothermal heat source temperature of 155 \({}^{\circ}\)C, R290, and R1234 ze(E) exhibit a continuous increase in net power at the proposed novel cycle. For R290 and R1234 ze(E), as their critical temperatures are approached, the increase in net work remains the dominant factor over the reduction in heat input within the investigated range. As a result, the net power continues to rise without showing a peak, unlike the behavior typically observed in ORCs with other fluids. Additionally, for some ORC evaporator temperature values, R290 and R1234 ze(E) cannot be used. These behaviors are also attributed to ORC evaporator temperatures approaching the critical point temperatures of these fluids. Analysis results show that the difference between the refrigerant temperature at ORC evaporator inlet and geothermal water temperature at ORC evaporator outlet becomes lower than pinch point temperature value of 5 \({}^{\circ}\)C.  
According to the results, the net power production has been found to be similar at lower ORC evaporator temperatures for all fluids. At the ORC evaporator temperature of 50 \({}^{\circ}\)C, net power production is approximately 29 kW and 80 kW for each fluid at heat source temperatures of 110 \({}^{\circ}\)C and 155 \({}^{\circ}\)C, respectively. However, the difference in net power production between fluids increases with increasing ORC evaporator temperatures. At the ORC evaporator temperature of 130 \({}^{\circ}\)C and the heat source temperature of 155 \({}^{\circ}\)C, the highest net power is 169.1 kW for R600a, while the lowest is 94.7 kW for R601. The effect of ORC evaporator temperature on net power production and the heat source outlet temperature for R601 at geothermal heat source of 110 \({}^{\circ}\)C are shown in Figure 16. Higher ORC evaporator temperatures result in higher outlet temperature of geothermal water (\(T_{2}\)) values. \(T_{2}\) is crucial if the heat source is intended for use in other applications after exiting the ORC evaporator. For instance, at 95 \({}^{\circ}\)C \(T_{Eva,ORC}\), the geothermal water outlet temperature is 94.42 \({}^{\circ}\)C which remains suitable for further applications. However, at 50 \({}^{\circ}\)C \(T_{Eva,ORC}\), the geothermal water outlet temperature is 45.78 \({}^{\circ}\)C, representing a significant difference.