Abstract: Using CO₂ phase change blasting instead of traditional explosive blasting as input energy,the physical transformation of "blasting and increasing permeability" of low-permeability sandstone uranium deposit is of great significance to improve the production of natural uranium in China.At present,the industrialized CO₂ fracturing device is mainly designed for coal and rock mining and other fields,and has poor adaptability in blasting seepage increasing conditions.Therefore,the porous design of the discharge head of the traditional crack maker is carried out to balance the pressure of each vent hole,which provides a theoretical reference for the design of the crack maker with "large and uniform pressure of each vent hole" in the field of blasting infiltration.RNG k-ε based on the turbulence model,the numerical simulation test of the energy discharge head of the crack breaker is carried out based on computational fluid dynamics (CFD).The gas flow law and pressure distribution characteristics in the energy discharge head are analyzed,and the influence law of the position relationship and the pore size characteristics on the pressure change of the vent hole is explored.The results show that in order to keep the stable output of pore pressure,the symmetrical distribution of vent holes is better than the staggered distribution of vent holes;At the same time,the diameter of the vent hole is set as a non-uniform type from the head to the end,which can effectively reduce the pressure difference between the pores.The above analysis results furhter show that the type of non-uniform and symmetrical energy discharge head is more in line with the needs of blasting infiltration.

Key words: CO₂ phase change blasting,blasting infiltration,CFD,energy discharge head,RNG k-ε turbulence model,numerical simulation