## 3 Verification and Validation of Condensation Heat Transfer Model
### Model Validation via Wisconsin Condensation Experiment  
In addition, to validate the surface condensation heat transfer model for the heat structure, the results of this paper are compared with the Wisconsin atmospheric partial condensation experimental data [15]. The Wisconsin experiment mainly studied the condensation heat transfer phenomenon in the presence of noncondensable gases. The experiment considered condensation on both vertical and horizontal flat plates in a large space. Six aluminum condensation plates, with a total length of 0.9144 m and a thickness of 0.3048 m, were installed on the top and side walls located in the upper-right corner of the container. The container was filled with humid air maintained at a constant temperature and pressure. The humid air led to the condensation of heat on the wall of the aluminum condensation plates. During the experiment, the external surface of the condensation plate was cooled using continuously subcooled water to keep the plate wall temperature constant inside the large container, and high-temperature steam was injected from the bottom of the container to maintain the initial constant temperature and pressure state under different operating conditions. By setting different initial thermal parameters, the condensation heat transfer coefficients were measured under different experimental conditions using the HFM (Heat Flux Meter) and CEB (Coolant Energy Balance) methods. Table 2 briefly lists the necessary initial parameters for each experimental condition. Figure 2: Comparison of calculation results of control volume coupled heat structure. (**a**) Pressure. (**b**) Gas temperature. (**c**) Wall heat transfer coefficient. (**d**) Wall temperature. In the Wisconsin experiment, two different methods were used to measure the convective heat transfer coefficient, but the uncertainty of the two measurement results was not given. Therefore, in order to improve the reliability of the experimental comparison results, the average value of the results obtained from the two measurement methods was used. During the modeling process, one side surface of the heat structure was subjected to convection heat transfer, while the other side was kept at a constant temperature, and the air with steam was condensed on the heat structure surface. Figure 3 shows the comparison of the heat transfer coefficients between the experimental data and calculation results of the condensation for the vertical and horizontal condensing plates, respectively. According to the initial parameters, it can be known that the mixed steam containing noncondensable gas will condense on the condensing plate. As can be seen from Figure 3, the condensation heat transfer coefficient calculated via the PISAA is basically consistent with the experimental data for all cases. However, for the conditions with relatively more noncondensable gas such as cases 1, 2, 3 and 4, the heat transfer coefficient is significantly lower than the other conditions. Taking conditions 1 and 6 of the vertical condensing plate as examples, when the molar fraction of noncondensable gas decreases from 0.795 to 0.42, the heat transfer coefficient increases from 75.8 W/m2K to 238.9 W/m2K. The heat transfer coefficient increases obviously with the decrease in noncondensable gas, which further indicates that noncondensable gas has a great influence on heat transfer.