Dynamic response characteristics of shaft explosion-proof door and fan blade under explosion shock wave

Understanding the dynamic response characteristics of vertical shaft explosion-proof doors and fan blades under the action of explosion shock waves, and ensuring the continuous, safe, and reliable operation of the main ventilation fan is of great significance for safe mine production. A small-scale air shaft fan explosion-proof door explosion propagation experimental system was designed and built based on the similarity theory, and the gas explosion shock wave propagation experiments were conducted. The reliability of the mathematical model for gas explosion shock wave propagation was verified by comparing the experimental results with numerical simulation results. Using the segmented relay simulation method combined with the UDF code written to describe the movement process of the explosion-proof door, the shock wave propagation process during a gas explosion in the II020611 return airway excavation face of the Yangchangwan Mine was simulated. The dynamic response characteristics of the vertical shaft explosion-proof door and fan blades under the action of the shock wave were studied. The study results show that: ① under the action of shock waves, the overpressure on the far airway side of the initial explosion-proof door is higher than that on the near airway side, and then there is a phenomenon of high overpressure zone moving from the far airway to the near airway side. Before the overpressure reaches its maximum value, the overpressure on the explosion-proof door is evenly distributed. ② Under the impact load, different high-pressure zones appear along the radial direction of the blade, and the overpressure value gradually increases from the edge of the blade to the center along the axial direction of the blade. Under the action of shock waves, the bending moment at the root of the blade suddenly increases to the highest value and then rapidly decreases. The larger the gas explosion equivalent, the faster the attenuation. The maximum bending moment generated by shock wave overpressure at the root of the blade is logarithmically related to the gas explosion equivalent. ③ For the peak moment at the root of the blade, the maximum moment occurs when the explosion-proof door is closed, followed by the passive opening of the explosion-proof door, and the minimum moment occurs when the explosion-proof door is actively opened. When the explosion-proof door is passively opened, the greater the gas explosion equivalent, the worse the pressure relief effect after the explosion-proof door is opened, and the influence of counterweight on the pressure relief effect after the explosion-proof door is limited. Compared to passive opening, actively opening the explosion-proof door in advance can significantly improve the pressure relief effect at the fan and enhance the survival ability of the fan under disaster conditions.