## 3 Result and Discussion
### Parametric Study
#### 3.2.2 Effects of the Operating Parameters  
The pressure drop in the TV2 (\(\Delta p_{TV2}\)) has a large impact on the power production of the turbine. Figure 6 illustrates that a rise in \(\Delta p_{TV2}\) introduces an increase of the exergy destruction for both TV2  
Figure 4: Effects of pinch temperature in cold storage: **(a)** conventional exergy analysis results; **(b)** advanced exergy analysis results. Figure 5: Effects of pinch temperature in heat exchangers: **(a)** conventional and **(b)** advanced exergy analysis results versus pinch temperature in heat exchanger 2; **(c)** conventional and **(d)** advanced exergy analysis results versus pinch temperature in heat exchanger 3.  
and system (\(\dot{E}_{\text{D},TV2}\) and \(\dot{E}_{\text{D},tot}\)) with sensitivities of 27.05 kW and 71.24 kW per MPa, respectively. The decreasing system exergy efficiency \(\varepsilon_{tot}\) originates in the decline of the turbine inlet pressure. The variation tendency of the endogenous exergy destruction in overall system \(\dot{E}_{\text{D},tot}^{\text{EN}}\) is similar to \(\dot{E}_{\text{D},tot}\) since very most of \(\dot{E}_{\text{D},tot}\) comes from \(\dot{E}_{\text{D},tot}^{\text{EN}}\). Moreover, the system avoidable exergy destruction is almost the same as the avoidable endogenous part, both decreasing slowly and then increasing gradually. The storage pressure in HST \(p_{7}\) has a significance role in determining the power consumed in compressor and the power produced in turbine. Figure 7 illustrates the variation of system exergy destructions and exergy efficiency by varying the storage pressure. A rise in storage pressure produces a decline in overall system exergy destruction \(\dot{E}_{\text{D},tot}\) with sensitivity of 75.10 kW per MPa, and thus the decreasing \(\dot{E}_{\text{D},tot}\) causes an increase in system total exergy efficiency \(\varepsilon_{tot}\). Therefore, the system endogenous part \(\dot{E}_{\text{D},tot}^{\text{EN}}\), avoidable part \(\dot{E}_{\text{D},tot}^{\text{AV}}\), and avoidable endogenous part \(\dot{E}_{\text{D},tot}^{\text{AV,EN}}\) all decrease with storage pressure. Figure 8 describes the variation of system exergy destructions and exergy efficiency by changing the compressor inlet pressure (\(p_{3}\)). It is observed that with an increase in compressor inlet pressure, the system exergy destruction \(\dot{E}_{\text{D},tot}\) decreases firstly with sensitivity of 21.26 kW per 0.1 MPa and then increases monotonically with sensitivity of 19.95 kW per 0.1 MPa. This phenomenon can be explained below. With a higher compressor inlet pressure, the exergy destruction of CS is decreased, and the changing extent becomes smaller with the increasing compressor inlet pressure, while the exergy destruction of compressors, heat exchangers and TV2 shows a larger increase. Therefore, the system exergy destruction decreases firstly and then increase. Moreover, the system exergy efficiency  
Figure 6: Effects of pressure drop in throttle valve 2: (**a**) conventional exergy analysis results; (**b**) advanced exergy analysis results. Figure 7: Effects of storage pressure: (**a**) conventional exergy analysis results; (**b**) advanced exergy analysis results. Figure 9 presents the impact of ambient temperature (\(\tau_{amb}\)) on system exergy destructions and exergy efficiency. It is observed that with an increase in ambient temperature, the system exergy destruction \(\hat{E}_{\text{D},tot}\) decreases firstly with sensitivity of 10.19 kW per Celsius degree and then increases monotonically with sensitivity of 13.78 kW per Celsius degree. The exergy destruction of heat exchangers is decreased with a higher ambient temperature, while the exergy destruction of CS shows a reverse trend. Moreover, with a larger ambient temperature, the change extent of exergy destruction within CS becomes larger than that within heat exchangers. Therefore, the refraction occurs in the figure.