Abstract:
To address the low extraction efficiency and rapid attenuation of gas concentration caused by unbalanced negative pressure distribution in underground coal mine gas extraction systems, as well as the inability to achieve precise matching between negative pressure and operating conditions due to information loss from monitoring blind zones in pipe networks, a pump-valve coordinated adaptive regulation method for extraction parameters is investigated. A parameter regulation criterion targeting the maximization of gas concentration and pure extraction flow rate is established, and a multilevel regulation strategy of “overall coarse adjustment-local fine adjustment” is proposed, which overcomes the limitation that adjusting a single power or resistance component alone is insufficient to realize dynamic matching of negative pressure, concentration, and flow rate in different regions. Based on the structural characteristics of underground extraction pipe networks and gas flow theory in pipelines, a real-time parameter calculation and intelligent regulation model for gas extraction networks is developed. Gas extraction regulation factors are defined with the valve resistance coefficient \xi and the supplied negative pressure of micro extraction pumps \Delta P as key characterization parameters. By integrating the global optimization capability of particle swarm optimization with the local convergence characteristics of the Newton method, a hybrid PSO(Particle Swarm Optimization)-Newton optimization algorithm is established. Model validation is conducted using field monitoring data from the 2308 working face of a coal mine in Henan Province, yielding calculation errors of 4.6%, 7.5%, and 3.3% for pressure, flow rate, and concentration, respectively, which fall within acceptable engineering limits. Regulation of the monitoring data increases gas concentration by 4.52% and pure extraction rate by 61.57 m
3/h, verifying the correctness of the model and achieving efficient optimization of regulation factors. A dynamic adaptive regulation platform for gas extraction parameters is developed and successfully applied to the 11306 working face of Sangbei Coal Mine in Hancheng, Shaanxi Province, resulting in an increase in gas extraction concentration of 1.09%-2.07%. Field tests indicate that continuous improvement in gas extraction concentration is achieved by the proposed method, although the regulation effect is influenced by extraction operating conditions and coal seam permeability, providing theoretical support and a technical pathway for safe and efficient gas extraction in coal mines.