Numerical Simulation And Experimental Research Of Spiral Flow Ventilation In The Mechanized Heading Face

In coal mine, the mechanized heading face is the chief place where dust is produced. It is also the place where gas and coal-dust explosion frequently occurs. How to prevent the outwards diffusion of dust and disperse gas collecting at roof a very important question but remains unsolved in tunneling ventilation.In order to solve above question, the traditional tunneling ventilation must be improved. In recent years, some researchers propose a new thought of using the spiral ventilation to improve airflow distribution to disperse gas at roof and prevent the outwards diffusion of dust. At present, this kind of ventilation has been applied in project and an encouraging result has been achieved. Because of airflow complex in the mechanized heading face, and the theoretical aspect of the spiral ventilation has seldom been involved. It still uses in attempt stage at home. In order to disseminate and apply the new technology much better, in this paper, the spiral ventilation is object of study. Aiming at the mechanism of action of spiral ventilation in the mechanized heading face, drawing support from hydromechanics, aerodynamics, turbulent jet theory and other relevance theory; adopting analogue experiment means and the computer simulation technology, from airflow structure of spiral ventilation, controlling mechanism and drift law of blow and exhaust flow etc., many aspects have been carried out system and synthetically study on the spiral ventilation:(1)Theoretical analysis the formation process of rotated air curtain about along-wall duct, define the mechanism of controlled dust and blows over of gas spiral ventilation.(2)Structure mathematic model of flow field of spiral ventilation is established. Selecting and using CFD commercial software FLUENT, the gas flow field of spiral ventilation is simulated, the best supply air parameter and the best ratio of blow and exhaust are obtained.(3)Using respirable dust and gas as representative, numerical simulation of dust and gas movement rule which is done under the control of spiral ventilation. Compare with the same ventilation parameters and working face parameters under ventilation of long positive pressure and short negative. The following results can be concluded: the spiral ventilation not only improves the dust collection effect of ventilation installation, but also it blows over the roof gas of the working face and protects the gas from aggregating at the roof, and has a good application prospect.(4)By simulation test, study impacts further of relevance factors over exhaust hood function, verify and theoretical analysis structure mathematic model of flow field of spiral ventilation.