# Experimental Study of a Novel Prototype of Dual-Cycle Two-Phase Cooling System for a Data Cabinet
## 3 Results and Discussion
### Data Room Overall Energy Consumption Analysis  
#### 3.4.1 The Effect of Data Room Temperature on IT Power  
Figure 13 offers the impact of server room ambient temperature and CPU temperature on server power consumption. During the testing period, by effectively managing the core temperature of the chip, the DTCS ensured the continuous and stable operation of the server at a room temperature of up to 35 \({}^{\circ}\)C, with no instances of downtime. However, when the internal fan speed of the server was uncontrolled, the increase in both room and chip temperatures led to a significant rise in IT power consumption. Specifically, as the chip temperature rose, the leakage current within the semiconductor devices increased, resulting in an elevated overall power consumption of the chip [36,39]. Additionally, an increase in fan speed led to heightened fan noise, which further contributed to an increase in IT power consumption. The growth in power consumption exhibited a stepped nonlinear pattern, with higher temperatures leading to faster rates of increase. When fan speed control was applied, the increase in IT power consumption with rising room and chip temperatures became linear and significantly smaller. Specifically, as the room temperature increased from 21 \({}^{\circ}\)C to 35 \({}^{\circ}\)C, the growth rate of IT power consumption decreased from 21.1% to 2.4%. Likewise, as the chip temperature rose from 68 \({}^{\circ}\)C to 78 \({}^{\circ}\)C, the growth rate of IT power consumption dropped from 6.5% to 1.6%. .4.2 The Effect of Cooling System Control Temperature on the Overall Energy Consumption of Data Room  
The total energy consumption of data centers primarily consists of the energy consumption of cooling systems and IT equipment. Although increasing the control temperature of the cooling system can reduce the energy consumption of the heat dissipation system, it simultaneously increases the energy consumption of IT equipment. In pursuit of energy savings in data centers, it is crucial to consider the minimization of the overall energy consumption of the machine room holistically, rather than solely focusing on maximizing the efficiency of individual systems. Based on the findings from previous research, this study establishes the two control temperature levels for the chip cooling system of 35 \({}^{\circ}\)C and 45 \({}^{\circ}\)C, corresponding to average chip temperatures of 67.5 \({}^{\circ}\)C and 75 \({}^{\circ}\)C, respectively. For the backplane cooling system, four control temperature levels are set as follows: 24 \({}^{\circ}\)C, 27 \({}^{\circ}\)C, 30 \({}^{\circ}\)C, and 33 \({}^{\circ}\)C, resulting in a total of eight distinct operating modes. The selection of these temperature points is supported by the power consumption data illustrated in Figure 13, ensuring the reliability and representativeness of the power data. Table 5  
Figure 13: IT Server power vary with the room and CPU temperature: (**a**) impact of room temperature on IT power; (**b**) influence of chip temperature on IT power. provides a detailed overview of the performance of the DTCS under various simulated conditions, aiming to conduct an in-depth analysis of the overall energy consumption of the data center under different modes. Figure 14 presents the annual total electricity consumption of a data center under different cooling system modes. Due to the suppressed fan speed of the servers, the impact of increasing the control temperatures of the chips and data cabinet on the annual power consumption of IT equipment is relatively small at this time, making the energy-saving effect of the cooling system particularly prominent, especially for the backplane cooling system. From mode 1 to mode 8, the IT power gradually increases, while the energy consumption of the cooling system fluctuates significantly, with the fluctuations in PBTCS being more pronounced.