## 3 Results and Discussion  
### Simulation Results with the Default Configuration  
Figure 8 and Table 3 present the internal parameter distribution and the simulation results for the PCTCS under default parameters. As illustrated in Figure 8a, the major pressure drops in the PCTCS transpired within the connecting pipes (2-3, 4-5, 6-7, and 8-1), whereas they were minor within the mini-channel evaporators (3-4, 5-6) and the plate-type condenser (7-8). This disparity arose from the model's focus on the heat exchange channels in the mini-channel evaporators and plate-type condenser, which exhibit lower refrigerant mass flux, resulting in smaller pressure drops. Pipe 6-7, despite having the same length as pipe 2-3 but a larger diameter, manifested a markedly higher pressure drop. This difference can be attributed to the high-quality two-phase state of the refrigerant in pipe 6-7 compared to the single-phase state in pipe 2-3. The total pressure drop of the system comprises the frictional pressure drop, the acceleration pressure drop, and the gravitational pressure drop. In the default configuration, all connection pipes are arranged horizontally, thereby the gravitational pressure drop in connecting pipes could be disregarded. Moreover, while the phase change process of the refrigerant in the evaporators and condenser did result in an acceleration pressure drop, its value was minuscule compared to the frictional pressure drop, thus it can be omitted too. Consequently, under the default conditions, the total pressure drop was almost entirely attributed to friction. A marked pressure drop was noted as the refrigerant coursed through pipe 6-7, a finding that aligns with the research conducted by [PERSON] and [PERSON] [30,31]. Their work indicates that the frictional pressure drop in two-phase flow is notably larger than that observed in single-phase flow. Given the length of pipe 6-7, it stands to reason that the refrigerant encountered the most significant frictional pressure drop there within the entire PCTCS. Interestingly, despite an absence of heat exchange within pipe 6-7, the quality of the refrigerant increased, due to both the pressure drop and the inherent physical properties of refrigerant R-113 [45], as represented in Figure 8b. As also noted in [PERSON] and [PERSON]'s studies [30,31], the frictional pressure drop of the two-phase flow typically escalates alongside an increase in refrigerant quality within the horizontal pipe. This correlation results in a gradual increase in the frictional pressure drop within pipe 6-7 as the refrigerant flows through it. Figure 8b presents the distribution of thermodynamic quality and void fraction. The variation trends of both parameters were aligned; as the thermodynamic quality escalated, the void fraction initially increased rapidly and then proceeded at a slower pace. Moreover, within the first mini-channel evaporator, nearly half of the zones displayed a thermodynamic quality of less than zero, indicating subcooling of the refrigerant. Conversely, few zones with a thermodynamic quality of less than zero were observed in the plate-type condenser. Figure 8c presents the distributions of temperature and the heat transfer coefficient. As observed, the subcooled refrigerant, upon initial entry into the first mini-channel evaporator, was situated within the fully developed region of subcooled boiling, accounting for approximately half of the heat transfer area of the first evaporator. In this region, the heat transfer coefficient incrementally increased with a corresponding decrease in the subcooling temperature, while the CPU temperature remained relatively constant. As the thermodynamic quality progressively increases, nearing zero, it transitioned into the void flow region, resulting in a sharp upsurge in the heat transfer coefficient and a slight decline in the CPU temperature. When the thermodynamic dryness exceeded zero, the system transitioned into the saturated boiling zone.