| ’ Rich coal,lack of oil and gas ’ is China ’ s national conditions,coal-based energy structure is difficult to fundamentally change in the short term.However,a large amount of dust will be produced in the process of coal mining.In order to reduce the dust content in the mining working environment and reduce the incidence of pneumoconiosis among coal miners,it is necessary to carry out dust reduction.Among them,the spray dust reduction technology has the characteristics of simple operation,economic and environmental protection,and wide application range.The spiral nozzle structure has the characteristics of simple,economic,practical,efficient and environmental protection,and is widely used in coal mine dust prevention and control places.Through theoretical analysis,numerical simulation and experimental research,a high-pressure spiral atomizing nozzle is optimized.The flow characteristics and droplet breakup law were revealed,and the atomization performance of the nozzle under different water supply pressures and different structural parameters was systematically studied.The nozzle structure was optimized based on orthogonal test to obtain the best parameters.The main research work and achievements of this paper include the following aspects :Firstly,the atomization mechanism and the process of droplet formation were analyzed,and the evaluation indexes of atomization quality such as water consumption,atomization angle and droplet size were clarified,which provided a theoretical basis for studying the influence of parameters on atomization performance.Secondly,the three-dimensional physical model of the internal and external flow field of the spiral nozzle is established.The FLUENT numerical simulation software is used to simulate the spiral nozzles with different parameters,and the atomization parameters such as the velocity distribution,water consumption and atomization angle of the nozzle outlet are obtained.The influence of various parameters on the atomization performance of the spiral nozzle is obtained.Then,the four factors of water supply pressure,outlet diameter,contraction angle and length-diameter ratio of the nozzle are selected.Each factor is reasonably divided into five levels to establish an orthogonal test table and carry out an orthogonal test.With nozzle water consumption and atomization angle as test indexes,the test data were processed by range analysis and variance analysis.After comparison and analysis of the test results,the nozzle with a water supply pressure of 6MPa,an outlet diameter of 1.6mm,a contraction angle of 70 °,and a length-diameter ratio of 0.2 has the best atomization effect.Finally,an experimental system was built to verify the effectiveness of the numerical simulation.At the same time,compared with the initial structural parameters and the optimized data,the water consumption increased by 288 %,the atomization angle increased by 56 %,and the atomization performance was significantly improved.Through the combination of theoretical analysis,numerical simulation and experimental verification,the influence of the structure size of the spiral nozzle on the atomization performance is studied,and the optimal design scheme of the nozzle is obtained.The analysis results in this paper have certain reference value for coal mine dust control.Figure 38 Table 17 Reference 72... |
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