高压水射流-机械齿联合破岩数值模拟研究

NUMERICAL SIMULATION FOR COMBINED BREAKING ROCK WITH HIGH PRESSURE WATER JET AND MECHANICAL BIT

采用非线性动态有限元法,结合实际工况条件,建立了高压水射流–机械齿联合破岩的数值模型。研究了高压水射流破碎岩石过程,并提出了2个临界压力的概念。计算结果表明,联合破岩的破碎效率约为高压水射流和机械齿分别破岩之和的2倍,射流和齿的间距在13mm左右最佳。当射流压力足够高时增大转速有利于提高破岩效果;当钻压增加到一定值后,其对破岩效率影响不大;破岩效率与静水压力成反比。

According to practical working situation, nonlinear dynamic finite element method is adopted to establish a numerical model of combined breaking rock with high pressure water jet and mechanical bit. Breaking process of rock with high pressure water jet is studied; and two critical pressure concepts are put forward. The conclusion that rock breaking process under high pressure water jet is divided into hammer impacting break and erosion break is proven by experiment to be true. Conclusions can be drawn from calculation results that the efficiency of the combined breaking rock is about 2 times as much as the summation of high pressure water jet and mechanical bit separately breaking rock; and the best distance between water jet and bit is about 13 mm. When the pressure of jet is high enough, the efficiency of breaking rock will be increased if rotation speed improves. Dropping down the drilling pressure properly to a certain value will not affect the efficiency of breaking rock. Hydrostatic pressure reacts on the efficiency of breaking rock.