Optimization of key parameters for continuous and precise nitrogen injection in goaf based on response surface...

Area of Science:

• Mining Engineering
• Fire Safety Science
• Chemical Engineering

Background:

• Coal spontaneous combustion in goaf presents significant fire hazards.
• Traditional nitrogen injection methods are often inefficient and wasteful.
• There is a need for optimized fire prevention and extinguishing technologies in goaf areas.

Purpose of the Study:

• To optimize continuous and precise nitrogen injection parameters for coal mine goaf fires.
• To minimize the width of the oxidation zone and carbon monoxide (CO) concentration.
• To improve the efficiency and resource utilization of nitrogen injection fire-fighting.

Main Methods:

• Response surface methodology and Box-Behnken design were employed.
• Self-developed continuous and precise nitrogen injection equipment was utilized.
• Key parameters studied included nitrogen injection position, amount, and air supply volume.

Main Results:

• Optimal parameters determined: nitrogen injection position at 54.17 m, amount at 31.04 m³/min, and air supply at 2484.81 m³/min.
• Achieved minimal oxidation zone width (29.21 ± 0.3 m) and CO concentration (28.1 ± 4.4 ppm).
• Model predictions closely matched experimental results, verifying the model's reliability.

Conclusions:

• The optimized continuous precise nitrogen injection effectively controls goaf fires rapidly.
• The study provides valuable data and lessons for similar nitrogen injection fire prevention and extinguishing technologies.
• This approach enhances fire safety and resource management in coal mining operations.