Characteristics of Harmful Hot Gas Group Migration and Ventilation Control after Mine Explosion.

To minimize the number of casualties due to poisoning in coal mine gas explosions, the migration characteristics of harmful hot gas groups in the mine ventilation system following an explosion were analyzed. Through pipeline experiments, initial CO concentrations and residual temperatures after gas explosions were determined and used as key simulation parameters. Simulations were performed using the TF1M(3D) software based on the case of the gas explosion at the Tunlan Mine. The migration trajectory of harmful hot gas groups in the mine ventilation system following an explosion was described in detail, and the impact of the failure duration of the main ventilator (Liangzhuang ventilator) on the migration characteristics of the harmful hot gas groups was analyzed. The results indicate that the migration direction of harmful hot gas groups in the mine ventilation system reverses before and after the Liangzhuang ventilator resumes ventilation, leading to a secondary invasion of the 12,403 and 12,405 working faces. Resumption of ventilation by the Liangzhuang ventilator prior to the 900 s mark can prevent the secondary invasion of harmful hot gas groups into the 12,403 and 12,405 working faces. The critical time point for miners to evacuate in the Liangzhuang area is 850 s, while for the Shijiahe area, it is 3500 s. The concept of harmful hot gas group expulsion efficiency in the Tunlan Mine was defined, and it was found to have a strong negative correlation with the failure duration of the Liangzhuang ventilator. It was determined that normal ventilation of the Liangzhuang ventilator is the key factor in controlling the migration trajectory of the harmful hot gas groups.