To prevent and contain mine gas explosion accidents, the explosion suppression performance of potassium salt powders and their action laws in the pipe network were deeply explored. In a pipe network with parallel pipelines, branching pipelines, and angular connecting pipelines, an experimental study on the suppression of gas explosions by three potassium salt powders, namely KHCO3, K2C2O4, and KH2PO4, driven by N2, was carried out. The pyrolysis characteristics of the powders were studied through thermogravimetric(TG) analysis. By combining explosion experiments, the overpressure changes were monitored. The explosion overpressure and overpressure attenuation coefficient under the action of potassium salt powder were explored. Moreover, the explosion suppression mechanism was analyzed with the assistance of the Chemkin-Pro simulation software. The results indicate that after the explosion suppression by the three powders, the superposition and attenuation process of the shock wave pressure is eliminated, and the overpressure time-history curve exhibits a "single peak value" characteristic. Among them, the KHCO3 powder has the best suppression effect on the explosion overpressure peak value, with a decrease range of 83.2% - 88.9%. K2C2O4 ranks second, and KH2PO4 is relatively weaker. The pressure attenuation degree in the oblique angular connecting branch pipe 4 is greater than that in other branch pipes. Both the branch pipe 4 and the turning section can leverage their own structural characteristics to enhance the overpressure attenuation effect, and they are regarded as preferred locations for installing explosive inhibitors. KHCO3 is able to maximize the utilization of this structural characteristic to enhance the explosion suppression effect. Additionally, the shock wave overpressure attenuation coefficient K2 of the branch pipeline section shows a situation where it is less than 1.This phenomenon is found to be exacerbated by the addition of K2C2O4 and KH2PO4 powders. Through the analysis using the Chemkin-Pro simulation software, it is concluded that the free radical content under the KHCO3 working condition is the lowest, and the explosion suppression effect is the best, followed by the K2C2O4 working condition, and finally the KH2PO4 working condition.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |