Numerical Simulations On Dust Removal Effect Of Coal Cutter Wet Dust Removal Fans And Related Engineering Applications In Fully Mechanized Coal Mining Face

With the increasing level of mechanization and automation of coal mining,the dust production of fully mechanized coal mining face is also increasing.Among them,the dust production of fully mechanized coal mining face accounts for more than 65% of the total dust production of the mine,and the dust production of coal cutter drum cutting is the largest dust source in fully mechanized coal mining face,accounting for about 70% of the total dust production of fully mechanized coal mining face.In the absence of any dust-proof measures,the dust concentration of fully mechanized coal mining face can reach 8000?10000 mg/m3,which seriously pollutes the working environment of the workface and threatens the miners' physical and mental health.In addition,the high concentration of dust in the workface will also cause coal dust explosion disaster,reduce the visibility of the workface,and reduce the service life of the equipment.In this thesis,theoretical analysis,numerical simulation,experiment and field application are combined to study the airflow-dust distribution law of fully mechanized coal mining face before and after installing dust removal fans,which provides theoretical guidance for the design and development of dust removal fans.Then,this thesis combines high efficiency atomization with dust extraction and purification to prevent and control the dust production of coal cutter,and develops a small hydraulic dust removal fans,thus gradually launching the topic of "Numerical Simulations on Dust Removal Effect of Coal Cutter Wet Dust Removal Fans and Related Engineering Applications in Fully Mechanized Coal Mining Face ".Firstly,Solidworks is used to model fully mechanized coal mining face precisely,then DesignModeler is used to name the geometric body,and Meshing is used to generate mesh.After setting parameters according to the measured data of dust source and airflow,the numerical simulation is carried out.Based on the mathematical model of continuous-discrete phase coupling and CFD calculation method,this thesis simulates the law of airflow-dust migration before and after installing dust removal fans in fully mechanized coal mining face,describes the airflow macroscopically with the streamline diagram,and makes a micro-analysis of dust particle migration and dispersion by the particle diagram.Finally,it is found that before installing dust removal fans,the overall airflow velocity shows the trend of "big in the middle and small on both sides";the high concentration dust above 1000 mg/m3 mainly concentrates in 0?33 m of the leeward side of the coal cutter.After installation,eddies appear on both sides of the coal cutter fuselage,and the airflow velocity of belt along the coal wall increases.The dust pollution area shrinks obviously,especially in the pavement area,only a small part of the dust belt distributes along the pillar.Then,the simulation analysis of the spray of the dust removal fans shows that the spray range completely covers the dust pollution area and can effectively reduce the dust.Then,the atomization performance of the nozzle was tested,and the optimum nozzle was selected from six typical nozzles.Based on the experimental platform of spray and dustfall,the macro parameters of the six kinds of nozzles,such as the flow rate,range and angle of atomization,and droplet size distribution,droplet velocity and other microscopic parameters were measured.Finally,the best nozzle was selected after comprehensive consideration.Finally,according to the field situation and simulation results,the layout of the hydraulic motor,hydraulic system and nozzle group of the dust removal fans is optimized.Field application has been carried out in Wanglou 27307 fully mechanized coal mining face.The average dust removal rates of total dust and respirable dust at six measuring points after application of dust removal fans are 53.0%and 55.7%.The dust concentration in the field has been greatly reduced,the dust control effect is excellent,the working environment of fully mechanized coal mining face has been optimized,and the occupational health of workers has been guaranteed.