| The drilling speed to shorten the drilling cycle plays a decisive role in drilling process.Using the fire-suction hydraulic impactor can achieve percussive-rotary drilling.It can enhance drilling speed,shorten gross drilling time and reduce capital investment.The fire-suction hydraulic impactor can transform drilling fluid’s pressure energy into mechanical energy.Withing bit static pressure,rotational cutting and vertical impact loading,the way of rock breaking will be faster and more efficient.The main research work are as follows:According to the working principle of this impactor,this paper reclassified hydraulic impactors and summarized the advantages and disadvantages of different types of hydraulic impactors, and analyzed torque impactor which is relatively less used.The study objects of the article are piston and hammer, using Newton’s second law to establish the corresponding kinetic equation equations displacement equations and find the relationship between parameters.Introduced the equipments and process of the indoor test.The flow channe of this fire-suction hydraulic impactor is open at the end stage of impacting and the differential pressure is forming.Established entity model of inner flow channe with Pro/E,meshed the model with Gambit,then imported in Fluent to operation and analysis. Studied on variation of differential pressure with changing the inner diameter of nozzle and restrictor ring and flow rate based on univariate analysis. Conclusion: smaller inner diameter of nozzle and restrictor ring,and larger flow rate can form larger differential pressure. Analyzed flow field which formed through nozzle of quadric curve and cubic curve in upper cavity. For the nozzle of quadric curve, smaller parameter of θ can form lower pressure in upper cavity. For the nozzle of cubic curve,the nozzle D(θ=30°) can form the lowest static pressure at the upper end of valve and piston.All the analysis above can improve the performance of this fire-suction hydraulic impactor. |
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