## 4 Processing of Experimental Data
### Solar Radiation Intensity and Ambient Temperature Variation Curve  
Figure 5 depicts the curves of solar radiation intensity and ambient temperature for 7 days, from 25 December 2023 to 28 December 2023, and from 2 January 2024 to 5 January 2024. After system initialization, the Programmable Logic Controller (PLC) automatically collects and stores data every minute. During the seven-day testing period, the system starts at 8:00 a.m. and shuts down at 5:30 p.m. each day. The average solar radiation intensity and ambient temperature are marked in the figure, with (t\({}_{0}\)) representing the daily average ambient temperature and (I\({}_{0}\)) representing the daily average radiation intensity. Under sunny conditions, the solar radiation intensity exhibits an arch-shaped variation with an initial increase followed by a decrease, with the system entering a high radiation range (600 W\(\cdot\)m\({}^{-2}\)) between 9:50 a.m. and 2:15 p.m. Under overcast conditions, the solar radiation intensity also shows a trend of increase followed by decrease, but the data are more dispersed, influenced by cloud distribution, movement, and wind, resulting \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Experiment Date** & **Weather Condition** & **Ambient Temperature** & **Radiation Intensity** & **Suction Temperature** & **Discharge Temperature** & **PVT Panel Temperature** & **PVT Panel Temperature** & **PVT Panel Temperature** & **PVT Panel Temperature** & **PVT Panel Temperature** & **PVT** & **PVT** & **PVT** & **Generation** & **Action Efficiency** & **COP** \\  & **tion** & \({}^{\circ}\)C & (W/m\({}^{3}\)) & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C & \({}^{\circ}\)C \\ \hline
30 & & & & & & & & & & & \\ December & Overcast & 16.94 & 369 & 4.82 & 86.47 & 12.68 & 25.59 & 19.92\% & 17.99\% & 2.44 \\
3 January & Cloudy & 16.06 & 483 & 4.27 & 85.66 & 14.4 & 21.4 & 21.12\% & 19.49\% & 2.61 \\
4 January & Sunny & 16.45 & 510 & 7.35 & 89.95 & 13.87 & 22.22 & 22.37\% & 20.54\% & 2.52 \\
25 & & & & & & & & & & \\ December & Sunny & 11.48 & 527 & 3.22 & 89.06 & 10.72 & 19.2 & 23.47\% & 22.83\% & 2.14 \\
2023 & & & & & & & & & & \\
2 January & Cloudy & 15.24 & 486 & 2.19 & 84.12 & 14.82 & 26.33 & 22.82\% & 0.2043 & 2.53 \\
2024 & & & & & & & & & & \\
5 January & Cloudy & 16.53 & 468 & 3.68 & 85.7 & 14.57 & 27.81 & 20.64\% & 0.1872 & 2.81 \\
2024 & & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Winter Experiment Data Sheet for Fuzhou. in fluctuating radiation intensity, occasionally reaching maximum (1093.62 W\(\cdot\)m\({}^{-2}\)) and minimum (296.16 W\(\cdot\)m\({}^{-2}\)) values. Under cloudy conditions, the solar radiation intensity exhibits oscillations and dispersion after reaching a certain value, due to the constantly moving sparse cloud layers causing changes in radiation intensity. During the experiment, the trend of ambient temperature change is similar to that of radiation intensity, both showing an initial increase followed by a decrease, and consistently staying above the initial temperature. The ambient temperature gradually decreases during system operation, reaching approximately 16 \({}^{\circ}\)C between 12:30 p.m. and 3:30 p.m., followed by a gradual decrease until system shutdown. The data indicate that during the period from 9:50 a.m. to 3:30 p.m., both solar radiation intensity and ambient temperature reach relatively high values, with solar radiation intensity reaching 600 W\(\cdot\)m\({}^{-2}\) and ambient temperature approximately 16 \({}^{\circ}\)C. Under high radiation intensity, the refrigerant can absorb more heat from the sun in the PVT panel, reducing the temperature of the PVT backboard and thereby increasing the system's electricity generation efficiency.