## 3 Results and Discussion
### Impact of the Condenser Height  
Figure 10 and Table 5 provide insights into the internal parameter distribution and performance characteristics of the PCTCS at different condenser elevations. Figure 10a,b depicts that disparate condenser heights generate similar P\({}_{\text{r}}\), Pdt, and Pdf distributions throughout the PCTCS, excluding connection pipe 8-1. Given the marginal impact of Pda, Pdt can be viewed as the summation of Pdf and Pdg. When the condenser was placed 1 m above the reservoir and evaporators, pipe 8-1 manifested a positive Pdf, contrasted by a negative Pdg and Pdt, which suggested an increase in P\({}_{\text{r}}\). Conversely, when the condenser was situated 1 m below or at an equivalent level, Pdg was either positive or zero, Pdf remained positive, and Pdt consistently stayed positive, indicating a decrease in P\({}_{\text{r}}\). Interestingly, despite the identical 1 m elevation difference in pipes 6-7 and 8-1, the impact of Pdg on Pdt was remarkably less in pipe 6-7. This observation could be ascribed to the two-phase state of the refrigerant in pipe 6-7, in accordance with Equations (8)-(10), where a high \(\alpha\) yields a small Pdg. Moreover, when the condenser was elevated by 1 m, the absolute value of the negative Pdg in pipe 8-1 escalated due to a decrement in \(\alpha\). Figure 10c-e implies that alterations in condenser height affect x and \(\alpha\), the dimensions of the subcooling area area, and h\(\alpha\) of the PCTCS. As the height of the condenser increased, the subcooling area during the evaporation and condensation process contracted, h\(\alpha\) diminished, and both x and \(\alpha\) of the PCTCS amplified. The impact became particularly pronounced when the condenser's elevation was increased by 1 m, which led the PCTCS to exhibit a two-phase state at the condenser outlet, signifying an absence of supercooling within the condenser. This phenomenon can be explained by the state of the refrigerant at the condenser outlet, which can be inferred inversely from the conditions within the reservoir and pipe 8-1. Considering that the refrigerant enters the reservoir in a saturated state and that no heat transfer occurs within pipe 8-1, it is evident that the state of the refrigerant at the condenser outlet is primarily influenced by the pressure drop in pipe 8-1. If the total pressure drop across pipe 8-1 is positive--indicating a lower pressure at point 1 than at point 8--the refrigerant at the condenser outlet will present in a subcooled liquid state. Moreover, the degree of subcooling will increase in direct proportion to the total pressure drop across pipe 8-1. On the other hand, if the total pressure drop across pipe 8-1 is negative, such that the pressure at point 1 exceeds that at point 8, the refrigerant at the condenser outlet will be  
in a two-phase state. Raising the condenser by 1 m introduces the factor of gravitational pressure drop, which results in a negative total pressure drop in pipe 8-1 and consequently leads to the emergence of a two-phase state at the condenser outlet. Figure 10: Internal parameter distribution of the PCTCS with different condenser heights: (**a**) pressure and total pressure drop distribution; (**b**) frictional and gravity pressure drop distribution; (**c**) thermodynamic quality and void fraction distribution; (**d**) temperature distribution; (**e**) heat transfer coefficient distribution. Table 5 illustrates that an increase in the condenser's elevation correlates positively with Pdt and Ppump, while inversely affecting EERp and \(\eta_{\text{con}}\). For instance, when the condenser was 1 m above the reservoir and evaporators, Pdt and Ppump registered at 78.14 kPa and 26.27 W, respectively. These parameters were lower than the 83.21 kPa and 27.9 W observed when the condenser was at the same elevation and the 92.53 kPa and 30.86 W when it was situated 1 m below. Simultaneously, the EERp for the PCTCS when the condenser was elevated by 1 m, situated at the same level, and placed 1 m below, was 122, 115, and 104, respectively.