## 3 Results and Discussions
### Sensitivity Analysis  
2.1 Effect of Turbine, Pump, Pinch Condenser, and Evaporator Efficiency on Energy and Exergetic Indicators  
Figure 3 shows the effect that the efficiency of the turbine and pump have on the energy and energy indicators of the system, using three working fluids. As for \(\Delta\)BSFC, it is observed in Figure 3a, for the percentage of specific fuel consumption savings of the ORC engine assembly with respect to the engine only, that the results reveal that the increase in turbine efficiency from 60% to 90% generates an increase of 1.54%, 1.99%, and 1.78% for toluene, acetone, and cyclohexane, respectively. However, the variation in pump efficiency in the same study range does not significantly affect the \(\Delta\)BSFC, yielding values of 0.041% for toluene, 0.0043% for acetone, and 0.049% for cyclohexane, according to Figure 3d. Also, it is observed that the increase of the turbine efficiency improves the combined power (gas engine plus ORC) 1.62% when the working fluid is toluene, 2.13% with acetone, and 1.89% for  
Figure 3: Effect of turbine and pump efficiency variation on **(a,d)** specific fuel consumption (\(\Delta\)BSFC), (b,e) Wcomb, and (**c,f**) exergetic efficiency using toluene, acetone, and cyclohexane as working fluids. cyclohexane, according to Figure 1b. However, the variation in pump efficiency still presents a slight variation that does not exceed 1%, as shown in Figure 3e. On the other hand, in terms of energetic analysis, the results show that the increase in turbine efficiency in the range of study generates an increase in energetic efficiency of 47.4% (toluene), 16.01% (acetone), and 14.1% (cyclohexane), as shown in Figure 3c. However, the variation in pump efficiency did not significantly affect the energetic efficiency, whose behavior was similar when studying the \(\Delta\)BSFC and the Wcomb. These results show that the efficiency of the turbine is a variable that significantly affects the energy and energetic performance of the system, with respect to the efficiency of the pump. However, even though the effect of the pump efficiency does not affect, to a great extent, the outputs of the energetic and exergetic indicators, these present higher values with respect to those reported when the turbine efficiency is varied, according to Figure 3c. Additionally, the most promising working fluid is toluene, compared to acetone, which presented a good performance when increasing the turbine efficiency. Figure 4 shows the behavior of the \(\Delta\)BSFC, Wcomb, and exergetic efficiency of the system as a function of the evaporator and condenser pinch. Figure 4a shows that the increase of the evaporator pinch causes a slight decrease of \(\Delta\)BSFC of 3.59% (toluene), 0.05% (acetone), and 0.16% (cyclohexane). In addition, when the Pinch condenser is increased, the \(\Delta\)BSFC decreases by 0.98% (toluene), 5.07% (acetone), and 7.16% (cyclohexane), as seen in Figure 4d. This behavior is similar to that obtained in Figure 4b,e, where the increase of the pinch evaporator generates a decrease of the combined power (Wcomb) of 2.88% (toluene), 0.06% (acetone), and 0.17% (cyclohexane) and a decrease of 1.02% (toluene), 0.30% (acetone), and 0.41% (cyclohexane) when the pinch of the condenser is increased. Finally, the exergetic efficiency also decreases when the condenser and evaporator pinch is increased, as a consequence of the lower energy recovery and increase of irreversibilities in this equipment. In this case, the exergetic efficiency of the system tends to decrease more when the pinch of the condenser with toluene is increased with respect to the other fluids. In this sense, acetone was the working fluid that produced the best results compared to toluene and cyclohexane. It also allows for reaching different performances in the system due to its great sensitivity to operational changes.