## 3 Temperature Characteristics Simulation
### Discussion and Results Analysis  
Specific to the flameproof cable box with a failure current at 180 A, Figures 13 and 14 depict the experimental and simulated temperature versus time curves, respectively. The two curves have the same trend of temperature rise; in this measurement time region, the temperatures at test points B and D increase rapidly, and the temperatures obtained at test points A and C remain consistent. As can be seen from the simulation results, the temperature at test point D is the first to reach the limiting temperature rise value at 1065 s, which is 80.831 \({}^{\circ}\)C, and the ambient temperature is 15 \({}^{\circ}\)C, with a corresponding temperature rise of about 65.831 K. The temperature at test point D is the first to reach the limiting temperature rise value. In the experiment, the temperature of measurement point D is 82.8 \({}^{\circ}\)C, the ambient temperature is 17.7 \({}^{\circ}\)C, and the corresponding temperature rise is about 65.1 K. The error between the two is 1.12%, which is in line with the standard. Figure 14: Temperature characteristic curve of coal mine explosion-proof cable box at 180 A under simulation. Figure 12: Schematic of the test points for the flameproof cable box for coal mines. Figure 13: Temperature characteristic curve of explosion-proof cable box for coal mine under experiment at 180 A current. Figures 15 and 16 present the temperature rise curves of the box at 240 A current under experiment and simulation, respectively. The results of temperature rise measured by simulation and experiment are similar, and the temperature reaches the limit value of temperature rise at the test point D first, the temperature limit of the box at 240 A current. They indicate that the temperature at Test Points B and D increased rapidly; the temperature at Test Point C is slightly above that at Test Point A. As can be seen from the simulation results, the temperature at test point D is the first to reach the limiting temperature rise value at 365 s, which is 80.234 \({}^{\circ}\)C, and the ambient temperature is 15 \({}^{\circ}\)C, with a corresponding temperature rise of about 65.234 K. In the experiment, the temperature of measurement point D is 85.5 \({}^{\circ}\)C, the ambient temperature is 19.9 \({}^{\circ}\)C, and the corresponding temperature rise is about 65.6 K. The error between the two is 0.06%, which is in line with the standard. Figures 17 and 18 illustrate the time-varying temperature curves of the box when the failure current was set to 300 A under experiment and simulation, respectively. The figures revealed that the temperature at Test Points B and D increased rapidly; the temperature at Test Point C was moderately higher than that at Test Point A, and the temperature at Test Point D was 84.0 \({}^{\circ}\)C at 210 s under experiment. In this case, the ambient temperature was 17.7 \({}^{\circ}\)C, and the corresponding temperature rise was approximately 66.3 K. The temperature at Test Point D was 81.898 \({}^{\circ}\)C at 210 s under simulation. In this case, the ambient temperature was 15 \({}^{\circ}\)C, and the corresponding temperature rise was approximately 66.898 K. The error between the two is 0.09%, and the two temperature rise results are similar. Figure 16: Temperature characteristic curve of coal mine explosion-proof cable box at 240 A under simulation. Figure 15: Temperature characteristic curve of explosion-proof cable box for coal mine under experiment at 240 A current. Figures 19 and 20 plot the time-varying temperature and temperature rise curves under the failure current set to 360 A for the box under experiment and simulation, respectively. Similarly, the temperature at Test Points B and D increased rapidly, the temperature at Test Point C was higher than that at Test Point A, and the temperature of Test Point D at 135 s was 86.7 \({}^{\circ}\)C under experiment.