## 3 Results and Discussion
### The Optimized Quasi-Steady State Results For Different Typical Days  
The quasi-steady state study under off-design conditions is calculated for the proposed system to examine the system performance. Then the system is optimized based on two main criteria, exergy efficiency and total exergy destruction rate. In the first scenario, the optimization is performed for the maximum exergy efficiency. The minimizing of the total exergy destruction rate is considered in the second scenario. According to the sensitive analysis, parameters such as: the turbine inlet pressure, the generator temperature, the temperature differences at the Absorber and condensers affect the system performance. The possible range of these parameters for optimization purpose is considered as follows:  
\[\text{maximize}\ \eta_{\text{xergy}}\ \text{and minimize}\ \dot{\text{E}}_{\text{D,tot}}\ (\text{TIP},\ \text{T}_{\text{gen}},\ \delta\text{T}_{\text{CON1}},\ \delta\text{T}_{\text{CON2}},\delta\text{T}_{\text{ABS}})\]  
\[11\leq\text{TIP}\ (\text{bar})\leq 32\]  
\[40\leq\text{T}_{\text{gen}}(^{\circ}\text{C})\leq 67\]  
\[5\leq\delta\text{T}_{\text{CON1}}(^{\circ}\text{C})\leq 25\]  
\[5\leq\delta\text{T}_{\text{CON2}}(^{\circ}\text{C})\leq 15\]  
\[5\leq\delta\text{T}_{\text{ABS}}(^{\circ}\text{C})\leq 17\]  
\[11\leq\text{TIP}\ (\text{bar})\leq 32\]  
It is noteworthy to mention that in all annual calculations for 10 typical days, the ammonia concentration in the power section is kept constant as \(0.5\ \text{kg}(\text{NH}_{3})/\text{kg}(\text{solution})\). The other operational parameters (pinch point temperature difference in the boiler, hot outlet-cold inlet temperature difference in the boiler, heat sink outlet temperature at the absorber, rectifier and condensers, reinjection geothermal hot water temperature) are calculated in off-design conditions for each 10 typical days category. The optimization results are presented in Figure 7 for maximum mean exergy efficiency and in Figure 8 for minimum mean total exergy destruction rate. In addition, the values of different operational parameters as well as the other parameters, which are obtained to optimize the system, are underlined in Table 1 for winter conditions and Table 2 for summer conditions in Appendix A.  
Figure 7: The mean energy and exergy efficiencies as well as the mean total exergy destruction rate of each typical day under optimization condition based on maximum exergy efficiency. In order to maximize the exergy efficiency based on yearly calculation in the proposed system, the \(\delta\)T\({}_{\text{CON2}}\) and \(\delta\)T\({}_{\text{ABS}}\) take their highest values, the \(\delta\)T\({}_{\text{CON1}}\) is considered its lowest value and the TIP and T\({}_{\text{gen}}\) are selected as the variable parameters. In the first scenario, the mean annual exergy and energy efficiencies are calculated to be 44.67% and 35.47%, respectively due to the weighting according to the frequency of typical days. The mean total exergy destruction rate in the first scenario is calculated to be 3412.83 kW. As indicated in Figure 7, due to the high values of heating demand in winter days in comparison to the transition and summer days, the exergy efficiency in winter days is higher. In the weather category of WWC, the higher mean exergy efficiency (53.21%) happens. In addition, the mean exergy efficiency in summer days takes the lowest value because of the lower values of heating demand. The lowest decrease of the mean exergy efficiency takes place at SSX due to the lowest value of required heating demand. The cooling demand in summer days is higher; however, the cooling exergy takes lower values in comparison to heating exergy. Besides, in the first scenario the highest and lowest mean energy efficiency occurs in the WWF and SSX with values of 53.12% and 19.07%, respectively. The lower mean energy efficiency in hot days happens due to the lower values of heat input to the system. The higher reinjection geothermal temperature brings about reduction in heat input.