Intelligent safety adjustment of branch airflow volume during ventilation-on-demand changes in coal mines

A pipe network ventilation parameter monitoring system is designed and developed based on typical ventilation network models. We confirm the VOD of the branch based on the absolute gas emission volume prediction model and then establish a regulating model for the ventilation resistance of associated branches and the ventilator frequency. Considering the fire and explosion risks associated with gas, CO2 is instead released to simulate gas emission in the experiment; gas concentration is controlled by the ventilation resistance of associated branches and ventilator frequency. These results verify that CO2 concentration is kept below the threshold value by increasing the air volume of the branch, the feasibility of the ventilation system, and regulating the VOD of the branch; additionally, they provide theoretical guidance for adjusting ventilation branch quantity by the association branches of ventilation resistance and ventilator frequency.