## 3 Experimental Results and Simulation Analysis
### Simulation Optimization Analysis
#### 3.3.2 The Impact of Different Humidity Sources on Dehumidification Efficiency  
According to [19], the relative humidity at the bottom of the cable trench is mostly maintained in the range of 70-80% during equipment operation. At this point, by changing the humidity of the humidity source, the dehumidification of each layout under different humidity levels can be analyzed. The bottom inlet humidity was set to 75%, 80%, 85%, and 100% as controls. The dehumidification process was examined by comparing the data distributions of different layouts in varying humidity conditions. The relative humidity and dew point temperature under various humidity conditions are illustrated in the following figures.  
Firstly, the bottom inlet humidity is 75%, and the data distribution diagram is shown in Figure 8a,b. Layout 4 still has advantages in terms of relative humidity and dew point temperature after steady state, with the lowest relative humidity being 45.1% and the highest only being 49%; the lowest dew point temperature is 17.2 \({}^{\circ}\)C, and the highest is only 17.3 \({}^{\circ}\)C. Secondly, the bottom inlet humidity is 80%, and the data distribution diagram is shown in Figure 9a,b. Layout 4 still has advantages in terms of relative humidity and dew point temperature after steady state, with the lowest relative humidity being 46.3% and the highest only being 50.6%; the lowest dew point temperature is 17.3 \({}^{\circ}\)C, and the highest is only 17.8 \({}^{\circ}\)C. Additionally, the bottom inlet humidity was 85%, and the data distribution diagram is shown in Figure 10a,b. Layout 4 still has advantages in both relative humidity and dew point temperature after steady state, with the lowest relative humidity being 45.6% and the highest only being 49.6%; the lowest dew point temperature is 17.2 \({}^{\circ}\)C, and the highest is only 17.5 \({}^{\circ}\)C. Finally, with the bottom inlet humidity of 100% as the control, the data distribution diagram is shown in Figure 11a,b. Layout 4 has more advantages in both relative humidity and dew point temperature after steady state, with the lowest relative humidity of 46.2% and the highest only 50.5%; the lowest dew point temperature is 17.3 \({}^{\circ}\)C, and the highest is only 17.8 \({}^{\circ}\)C  
In summary, after model optimization, even when the humidity of the humidity source is different, the overall dehumidification of each layout has a similar trend as the previous experiments and simulations before optimization. Layouts 2 and 4 are better than Layout 1, while Layout 3 has the worst effect; Layout 4 has the best dehumidification overall compared to other layouts when the humidity of the humidity source is different. Referring to the condition of 100% relative humidity of the humidity source, under three humidity conditions of 75% and 85%, after Layout 4 reaches steady state, the relative humidity at the measuring point can be reduced by up to 10.6%, reaching as low as 45.1%; the dew point temperature decreased by 2.61 \({}^{\circ}\)C, dropping to 17.2 \({}^{\circ}\)C. Under different humidity conditions, the maximum difference between the maximum relative humidity  
Figure 9: (a) Distribution of relative humidity data at 80% bottom inlet humidity; (b) distribution of dew point temperature data at 80% bottom inlet humidity.  
values at each measuring point is only 1%, and the maximum difference between the minimum values is only 1.6%; the maximum difference between the maximum dew point temperatures is only 0.1 \({}^{\circ}\)C, and the maximum difference between the minimum values is only 0.5 \({}^{\circ}\)C, indicating that the dehumidification of Layout 4 is sufficiently stable.