Research On Flow Field And Gas Distribution In Gob Of Y-type Ventilation Mining Working Face

At present, with the development of gob-side entry retaining technology, peoplebegan to use the Y-type ventilation, to solve gas excess problem in the upper corner andreturn airway.So researching on ventilation leakage and gas distribution in gob with Y-type ventilation has greatly important theoretical and practical significance forincreasing the gas drainage efficiency, controlling gas beyond in upper corner,preventing the spontaneous combustion in gob and gas explosion. to solve gas excessproblem in the upper corner and return airway. In order to ensure the reliability ofsimulation results, this paper studied the effect to the simulation results based on lengthof intake and return airways. Through research to determine the appropriate physicalmodel and boundary layer meshing method. According to the basic theory ofcomputational fluid dynamics, the paper chooses the control equations of ventilationleakage and gas distribution in working face and gob. The Y-type ventilation model ofworking face and gob under Y-type ventilation was established by using Gambit.Through the Fluent software, the paper researches on ventilation leakage and gasdistribution in working face and gob with Y-type ventilation.The simulation results shows that, Y-type ventilation air flow from the intakeairway in,flow flowing through the face channel, part of the them leakage into the gob,and eventually converge to the gob, at last through the gob, the air leakage into gob istoo much, the concentrations of gob is lower; the concentration of gob gas distribution:along the length direction of the gob, the more deep the greater the gas concentrationnear the gob; the concentrations of gob along the face direction close to the intake ishigh, but the concentration of gob near the gob side is low; the Y-type ventilation withtwo inlet and one return. when the total quantity is invariable, if the ratio of the massflow in the intake airway is increasing, the gob air leakage is increases too; theconcentration of gas decreases; no matter from the air inlet side or the return side,mining spontaneous combustion in gob and suffocation zone becomes smaller, coolingzone becomes larger gradually reduced; on Y-type ventilation one inlet and two return,with the gob-side entry retaining total return air ratio increasing, the higher numerical concentration of gas contour is receding, mining spontaneous combustion in gob andsuffocation zone becomes smaller, cooling zone becomes larger gradually reduce.