Study on Gas Migration Characteristics during Asynchronous Reverse Ventilation of Multiple Air Shaftsa

Abstract

To comprehensively understand the gas migration characteristics of ventilation systems during mine reverse ventilation periods, a high-precision three-dimensional dynamic simulation model was constructed using the TF1M3D simulation platform. The model’s reliability was validated through comparison with actual measurement data from Daxing Coal Mine. The study investigated the spatiotemporal distribution characteristics of gas concentration within the 3D ventilation net during asynchronous reverse ventilation periods of multiple air shafts, the relationship between fan downtime and gas parameters, and the influencing patterns of ventilation control on gas migration. Results indicate that simulation errors for multiple air shafts asynchronous reverse ventilation in mines are less than 5% compared to measured gas concentrations. The simulation accuracy for disaster ventilation is excellent, accurately describing changes of gas composition in the mine system during reverse ventilation. Implementing reverse ventilation operations in the mine resulted in a significant increase in gas concentration in the intake roadways of the working face, with peak values exceeding 1% within 520 seconds. After a brief peak, the concentration gradually decreased and stabilized after 1100 seconds. The duration of fan shutdown during reverse ventilation positively correlates with both the peak gas concentration and the peak area. Increasing fan speed reduces gas accumulation in the mine by over 13%, though short-term peak concentrations may rise. These findings provide theoretical and technical support for mine reverse ventilation drills.