Experimental Study on Hydraulic Characteristics in Baffle-Drop Shaft During Gas Explosion

In order to investigate the response relationship between the gas explosion mechanism and parameters such as water depth, inlet pressure, inlet volume, and connected area of dry/wet areas, a 1∶50 scale hydraulic model test system was first conducted to observe the gas explosion jetting process and analyze the variation law of pressure in the shaft. Secondly, a prediction model for the maximum jetting height of the shaft and the critical conditions of the gas explosion were established according to the definition of the gas explosion. Finally, the influences of different variables on the impact load of different baffles in the bottom of the shaft were compared. The results show that the pressure in the baffle-drop shaft fluctuates sharply during a gas explosion. On the one hand, it is caused by the release of high-pressure air mass; on the other hand, high-speed movement of the air-water mixture makes the local pressure in the shaft imbalanced, which contributes to strong fluctuation. The empirical formula established by the multiple linear regression model can effectively predict the maximum jetting height of the baffle-drop shaft. The critical condition established according to the response relationship between the gas explosion intensity and different variables can accurately determine whether a gas explosion occurs. Except for the inlet pressure, submerged state of the baffle, and measured point location, the hydrodynamic load on the baffle in the bottom of the shaft during the gas explosion is also related to the randomness of air-water mixture jetted on the baffle bottom. The maximum hydrodynamic load on the baffle bottom during a gas explosion is more than 10 times as much as the hydrodynamic load on the baffle surface under normal discharge conditions. © 2023 Science Press. All rights reserved.