## 3 Results
### The Influence of Loads on the Results  
The next stage in this analysis is the study of the different design scenarios in order to check the unit performance for different load demands. Figure 14 illustrate the performance of the system when the cooling and heating loads are varied. Each time, only one parameter changes while the others are kept at their default values. The trigeneration scenario is studied, which means that all loads are equal to 100 kW (see Table 1). The ambient temperature is 25 \({}^{\circ}\)C, while the high heating temperature is variable. More specifically, in each case, the (\(T_{heat,h}\)) is optimized in order to maximize the system exergy efficiency. This simple optimization is conducted with the EES by using the \"Golden Section Research\" method which is supported by the same software. The relative tolerance was chosen at \(10^{-6}\) and the maximum function calls at 1000. Figure 13: The impact of ambient temperature on energy input from the ambient for both trigeneration and cogeneration scenarios. Figures 14 and 15 show the impact of the cooling loads on the results. Specifically, Figure 14 depicts the influence of this load on the input electricity, output electricity and heat input in the system. Higher cooling load needs greater electricity consumption which is an acceptable result thermodynamically. The electricity production and ambient heat input decrease with the cooling load increase because the optimum high heating temperature also decreases. It is useful to set the optimum high heating temperature at 144.5 \({}^{\circ}\)C for zero cooling load and 108.5 \({}^{\circ}\)C for a cooling load of 130 kW. According to Figure 15, both energy and exergy efficiencies increase with the augmentation of the cooling load. For zero cooling load (a cogeneration case), the energetic efficiency was 201.61% and the energetic efficiency was 42.33%. For the case with the maximum cooling load of 130 kW, the energy and the exergy efficiencies were 350.81% and 46.03%, respectively. The next step is the investigation of the medium temperature heating production (or space-heating production) on the results. Figure 16 shows that higher space-heating demand increases the need for electricity input, as well as the heat input from the ambient. On the other hand, electricity production from the ORC presents a slight reduction due to the small variation of the optimum high heating temperature. Specifically, for space heating at 70 kW, the optimum high heating temperature is 116.6 \({}^{\circ}\)C, while for space heating at 200 kW it is 12.8 \({}^{\circ}\)C. Figure 17 indicates that both energy and exergy efficiencies increase with the augmentation of the space-heating demand. In this case, the energy efficiency ranged from 29.68% to 394.22%, while the exergy efficiency ranged from 44.47% to 47.13%. Figures 18 and 19 illustrate the influence of the high-temperature load on the unit behavior. According to Figure 18, the increase in high heating production leads to input electricity, produced electricity and heat input from the ambient to be increased. The optimum high heating temperature is found at 95.8 \({}^{\circ}\)C for \(Q_{heat,h}\) = 50 kW and at 133.5 \({}^{\circ}\)C for \(Q_{heat,h}\) = 200 kW. Figure 19 indicates that both energy and exergy efficiencies have a decreasing rate when higher amounts of heating are stored at the high-temperature level. This shows the need to store only the redundant quantities of energy in the high-temperature levels and not to design the high storage temperature level in high capacity. Figure 14: Ambient energy input and electricity rates for different cooling loads. Specifically, the energy efficiency ranged between 204.39% and 456.95%, while the exergy efficiency ranged between 42.34% and 48.98%. Figure 16: Ambient energy input and electricity rates for different medium heating loads. Figure 15: System energy and exergy efficiencies for different cooling loads. Figure 17: System energy and exergy efficiencies for different medium heating loads.