Test study on flow field morphology of high-pressure abrasive water jet and erosion and failure characteristics of coal
HE Bingbing
REN Qiheng
WANG Qingxiang
ZHANG Fucheng
MA Lingjun
XU Yayou
WANG Baofu
SONG Xiaolin
Abstract：In view of the demand for coal mine gas control,this study took a coal sample from a mining area in Inner Mongolia as the research object,and carried out a study on the coal breaking mechanism of quartz sand abrasive jet based on the theory of hy-draulic pressure relief and permeability enhancement.By precisely regulating the blending ratio of quartz sand in the pre-mixed ab-rasive water jet system and using the control variable method,the influence laws of three key parameters,namely jet pressure,im-pact target distance and nozzle diameter,on the morphological characteristics of the abrasive jet and the evolution of coal body dam-age were mainly investigated.The results show that:with the extension of the jet injection distance,both the pure water jet and the abrasive jet present the edge atomization diffusion phenomenon,and the edge atomization of the abrasive jet is more intense.When the jet pressure increases,the divergence degree of the outer contour of the jet expands and the divergence occurs earlier.The com-parison of erosion efficiency shows that under the working conditions of 5 MPa and 6 MPa,the crushing volume of quartz sand ab-rasive jet is 4.65 and 7.82 times that of pure water jet respectively,confirming that abrasive blending significantly improves the en-ergy conversion efficiency.When impacted in the near-field,the shape of the crushing pit is deep and narrow.When acted in the far-field,the jet diverges,the impact kinetic energy decays,and the shape of the crushing pit is shallow and wide.The nozzle structure optimization experiment shows that with a nozzle diameter of 3.0 mm,an optimized crushing pit with a depth of 27.67 mm and a dia-meter of 42 mm is formed,and the crushing volume is increased by 2.36 times compared with the nozzle diameter of 1.5 mm.When the nozzle diameter exceeds 3.5 mm,the abrasive accelerates the phase separation,resulting in a decrease in concentration and a 16.2%attenuation of the crushed volume.
Keywords：hydraulic flushingpressure relief and permeability improvementhigh pressure abrasive water jetssolid-liquid two-phase coupling mechanismimpact breaking coalcoal breaking mechanism
Publication Date：2025-08-20
Online Publishing Date：2025-08-18(First online date of this platform, not the publication date of the document)
Pages：9( 116-124 )