【摘要】 在粒子射流冲击破岩过程中,喷嘴作为粒子和水射流的核心加速装置,其加速能力决定了破岩效果的好坏。针对锥直型、等变速型和流线型喷嘴,建立了粒子和水射流在喷嘴中的加速模型、压降模型以及能量转换效率数学模型,通过数值模拟分析了不同喷嘴对粒子水射流加速能力的影响,对喷嘴的流道类型及尺寸进行了优化,依据优化结果对研制的喷嘴进行了破岩试验和流场仿真。分析结果表明:收缩段长度为15 mm的等变速型喷嘴具有较高的加速能力和能量转换效率;研制的喷嘴可应用于粒子冲击钻井破岩工艺。所得结论可为粒子射流冲击破岩装置的现场应用提供参考。更多还原

【Abstract】 As a core accelerating device of particles and water jet during particle jet impact rock breaking process,the nozzle’s accelerating ability determines the effect of rock breaking. On account of the straight-taper nozzle,the constant-acceleration nozzle and the streamline nozzle,the acceleration model,pressure drop model and energy conversion efficiency mathematical model of particle and water jet in the nozzle were established. The influence of different nozzles on the acceleration of particle water jet was analyzed by numerical simulation. The nozzle flow channel type and dimension were optimized. The rock breaking test and flow field simulation have been conducted on developed nozzle based on the optimization results. The analysis results show that the constant-acceleration nozzle with 15 mm retraction section has higher acceleration capacity and energy conversion efficiency. The new developed nozzle can be applied to particle impact rock breaking in drilling. The conclusion can provide references for the field application of particle impact rock breaking device.更多还原