## 3 Results and Discussion
### Influence of Different Ventilation Conditions
#### 3.2.2 Influence of Different Ventilation Temperatures  
To study the effect of the ventilation temperature on the distribution of temperature and moisture content inside the wheat pile, numerical simulations were conducted on the wheat pile with an initial temperature of 34 \({}^{\circ}\)C and an initial moisture content of 12.50%. Three conditions of different ventilation temperatures of 15 \({}^{\circ}\)C, 17 \({}^{\circ}\)C, and 19 \({}^{\circ}\)C were studied. Figure 7 shows the temperature distribution cloud map inside the wheat pile under continuous ventilation with different ventilation temperatures of 15 \({}^{\circ}\)C, 17 \({}^{\circ}\)C, and 19 \({}^{\circ}\)C for 24 h. The highest temperatures inside the wheat pile of at temperatures of 15 \({}^{\circ}\)C, 17 \({}^{\circ}\)C, and 19 \({}^{\circ}\)C were 29.32 \({}^{\circ}\)C, 29.44 \({}^{\circ}\)C, and 29.63 \({}^{\circ}\)C, respectively. The low-temperature air enters the wheat pile, then generates a strong heat exchange with wheat particles, causing a cold front surface toward the interior of the grain pile. However, the area of the low-temperature cold front inside the wheat pile was smaller due to the shorter ventilation time, and the size of the cold front decreased with the increase in ventilation temperature. The areas of high temperature were all concentrated in the center of the wheat pile, and the area covered by the high temperature increased with the increase in ventilation temperature. This may be due to the fact that the direction of the incoming air flow tends to be horizontal as the height of the ventilation cage decreases, causing low-speed cold air in the middle and lower parts to collect in the middle. Then, they flowed out along the grain surface in an upward direction. When the ventilation temperature increases, the amount of heat absorbed by the cooling airflow decreases, resulting in an increase in the area of high temperature. Figure 6: Temperature distribution at different ventilation cage heights: (**a**) 2.1 m; (**b**) 1.4 m; (**c**) 0.7 m.  
Figure 8 shows the temperature distribution cloud map inside the wheat pile under continuous ventilation with the different ventilation temperatures of 15 \({}^{\circ}\)C, 17 \({}^{\circ}\)C, and 19 \({}^{\circ}\)C for 48 h. At this time, the highest temperature inside the wheat pile at the three temperatures of 15 \({}^{\circ}\)C, 17 \({}^{\circ}\)C, and 19 \({}^{\circ}\)C decreased to 19.97 \({}^{\circ}\)C, 20.93 \({}^{\circ}\)C, and 21.99 \({}^{\circ}\)C, respectively. Compared with the results of the 24 h experiment, the area of the cold front inside the wheat pile gradually increased with the increased ventilation time, and the overall temperature inside the wheat pile significantly decreased. Moreover, the temperature stratification characteristics were also not as obvious as they were at 24 h. In addition, the highest temperature inside the wheat pile represented a ventilation temperature decrease of 15 \({}^{\circ}\)C, compared with 9.35 \({}^{\circ}\)C at 24 h. This indicates that a lower ventilation temperature causes the temperature inside the wheat pile to decrease faster under the same ventilation rate conditions. Figure 8: Temperature distribution cloud map for 48 h of ventilation under different ventilation temperatures: (**a**) 15 \({}^{\circ}\)C; (**b**) 17 \({}^{\circ}\)C; (**c**) 19 \({}^{\circ}\)C.  
Figure 7: Temperature distribution cloud map for 24 h of ventilation under different ventilation temperatures: (**a**) 15 \({}^{\circ}\)C; (**b**) 17 \({}^{\circ}\)C; (**c**) 19 \({}^{\circ}\)C.  
Figure 9 shows the temperature distribution cloud map inside the wheat pile under continuous ventilation with the different ventilation temperatures of 15 \({}^{\circ}\)C, 17 \({}^{\circ}\)C, and 19 \({}^{\circ}\)C for 96 h. With these temperatures of 15 \({}^{\circ}\)C, 17 \({}^{\circ}\)C, and 19 \({}^{\circ}\)C, the highest temperature inside the wheat pile decreased to 16.45 \({}^{\circ}\)C, 18.48 \({}^{\circ}\)C, and 20.34 \({}^{\circ}\)C, respectively.