## 5 Results and Discussions
### Parametric Analysis
#### 5.1.3. Effects of the Generator Outlet Temperature (T\({}_{\rm A8}\))  
Then, the influences of key parameters of AHP bottoming cycle on the overall system performances are investigated. As the single sCO\({}_{2}\) cycle and the sCO\({}_{2}\)/DH system have no AHP bottoming cycle, only the sCO\({}_{2}\)/ammonia-water AHP system and the sCO\({}_{2}\)/LiBr-H\({}_{2}\)O AHP system are analyzed here. Figure 6 shows the variation of \(\eta_{ex}\) and \(c_{total}\) with the generator outlet temperature \(T_{\rm A8}\) for these two combined systems. As \(T_{\rm A8}\) increases, \(\eta_{ex}\) increases to a peak and next goes down slightly, while \(c_{total}\) shows an opposite trend in Figure 6a, which indicates that there exists a \(T_{\rm A8}\) to optimize the overall system performances for the sCO\({}_{2}\)/ammonia-water AHP system. The _COHP_ also ascends firstly and then descends with \(T_{\rm A8}\). In order to explain this phenomenon, Figure 7a presents the mass flow rate of stream A8 (\(m_{\rm A8}\)), the total mass flow rate of ammonia water (\(m_{\rm A4}\)), the pump power consumption (\(W_{\rm pump}\)), and the exergy that heat users obtain (\(E_{h,users}\)) varying with \(T_{\rm A8}\). Clearly, as \(T_{\rm A8}\) increases, the heat absorption amount per unit mass flow rate from the topping cycle increases, so that the total mass flow rate \(m_{\rm A4}\) descends and then leads to the decline of \(W_{\rm pump}\). \(m_{\rm A8}\) increases firstly with \(T_{\rm A8}\) as more working fluid is evaporated from the generator solution. More ammonia vapor flows into the condenser and releases the considerable latent heat to the heating water, so that \(E_{h,users}\) increases correspondingly. Then, as the effect of decreasing \(m_{\rm A4}\) dominates when \(T_{\rm A8}\) is larger, both \(m_{\rm A8}\) and \(E_{h,users}\) decrease with \(T_{\rm A8}\). Therefore, _COHP_ and \(\eta_{ex}\) increase and then decrease with \(T_{\rm A8}\) according to Equations (41) and (42).  
Figure 6 shows the variation trends of \(\eta_{ex}\), \(c_{total}\), and _COHP_ with \(T_{\rm A8}\): (a) a sCO\({}_{2}\)/ammonia-water AHP system; (b) a sCO\({}_{2}\)/LiBr-H\({}_{2}\)O AHP system.  
The following Figure 7 shows the variation trends of \(m_{\text{A8}}\), \(m_{\text{A4}}\), \(W_{\text{pump}}\), and \(E_{ht,users}\) with \(T_{\text{AS}}\): (a) a sCO\({}_{2}\)/ammonia-water AHP system; (b) a sCO\({}_{2}\)/LiBr-H\({}_{2}\)O AHP system.  
Figure 6: Variation trends of \(\eta_{ex}\), \(c_{total}\) and \(COHP\) with \(T_{\text{AS}}\): (a) sCO\({}_{2}\)/ammonia-water AHP system; (b) sCO\({}_{2}\)/LiBr-H\({}_{2}\)O AHP system.  
For the sCO\({}_{2}\)/LiBr-H\({}_{2}\)O AHP system, the same trends can be observed for the _COHP_, \(m_{AA}\), \(m_{AB}\), \(W_{\text{pump}}\), and \(E_{\textit{L,users}}\) in Figures 6b and 7b, which will not be explained again here. It should be noted that the operational pressure of LiBr-H\({}_{2}\)O AHP is much lower than that of ammonia-water AHP, so the pump power consumption \(W_{\text{pump}}\) in LiBr-H\({}_{2}\)O AHP is also lower than that in ammonia-water AHP, as shown in Figure 7.