目前,水力割缝技术已经成为治理煤矿瓦斯灾害,实现煤层卸压增透的主要手段之一.高压气液两相射流作为一种新型高效的多介质强力射流,在冲蚀破岩性能上优于传统单介质射流.为了提高高压气液两相射流的破煤性能和卸压增透效果,通过改变高压气液两相射流的含气率、射流压力、冲击靶距以及喷嘴直径等基本参数,并结合超声波系统,探究了关键参数对两相射流冲击破煤的影响.结果表明:高压气液两相射流的冲击侵蚀破煤比传统纯水射流效果更显著,并且当含气率Fa=30%,射流压力Pw=10MPa,冲击靶距Ds=300mm,喷嘴直径Dn=3.5mm时,气液两相射流冲击破煤的效果更好.试验研究结果对于含气率、射流压力、冲击靶距及喷嘴直径等关键参数的选择提供了合理的参考,有效地提高了高压气液两相射流冲击破煤的效果.

At present, hydraulic cutting technology has become one of the main means to control coal mine gasdisaster and realize the pressure discharge of coal seam. As a new type of highly efficient multi-medium powerfuljet, the high-pressure gas-liquid two-phase jet is better than the traditional single-medium jet. In order to improvethe coal breaking performance and pressure increasing effect, the basic parameters, such as the gas content, jetpressure, impact target distance and the nozzle diameter on the impact of the two-phase jet are combined with theultrasonic system. Results show that the impact erosion of high-pressure gas-liquid jet is more significant than thetraditional pure water jet. When the gas content Fa = 30%, the jet pressure Pw = 10 MPa, the impact targetdistance Ds = 300 mm and the nozzle diameter Dn = 3.5 mm, the gas-liquid two-phase jet is better. The test resultsprovide a reasonable reference for the selection of key parameters, such as gas content, jet pressure, impacttarget distance and nozzle diameter, and effectively improve the effect of high-pressure gas-liquid two-phase jetimpact on coal breaking.