A multi-objective optimal collaborative gas flow regulation method for non-stationary ventilation network based on improved NSGA-Ⅲ algorithm

After the shockwave of a coal and gas outburst disappears, the influx of a high concentration of gas causes ventilation network disorder. This will further lead to the occurrence of secondary disasters, resulting in serious human and economic losses. This study focuses on solving the cooperative regulation problem of non-stationary ventilation networks (NSVNs) after a disaster. The NSVN solution model is dynamically combined with the ventilation network regulation method to simulate the results of post-disaster cooperative regulation. The Pareto optimal solution for decision variables is obtained with the goals of reducing the affected area, preventing the reversal of branch airflow, and rapidly discharging the high concentration of gas. In this regard, an NSGA-III algorithm based on segmented hybrid coding with conditional distribution sampling is designed to solve the problem of the population crossover operation under the dynamic change of the decision variables. In addition, according to the applicability of the decision variables in the regulation of NSVNs, the sampling distribution function that meets the practical application requirements is selected. Moreover, conditional distribution sampling is carried out for chromosome generation via real number coding, the aim of which is to improve the search efficiency and optimization effect. Via the hierarchical logical relationship between the decision variables, conversion is carried out to generate population individuals of different dimensions to realize the dynamic inputs of the NSVN solution model and calculate the corresponding target values. Finally, the feasibility of the proposed model and solution method is verified by studying and analyzing the case of an airflow disaster in a coal mine in Jiulishan, China. This study provides theoretical support for the cooperative regulation of NSVNs, as well as guidance for the post-disaster emergency rescue work in possible coal and gas herniation accidents.