On the Factors of Impact Pressure in Supercritical CO2 Phase-Transition Blasting—A Numerical Study

Abstract

Carbon dioxide phase transition blasting (CO2-PB) technology is an effective and economical technology used for breaking rocks. The use of CO2-PB can significantly reduce the vibration damage to surrounding rocks. There is little research on the shockwave generated by the CO2-PB, and simulation can better show the flow field characteristics. In order to clarify the mechanism of its blasting load process, a theoretical analysis and a numerical model were developed to study the flow-field characteristics and the impact pressure of CO2-PB. Our results show that the CO2 absorbs heat from the surrounding environment, producing a significant low-temperature area. The overpressure is significantly lower than the driving gas pressure to the ambient pressure, limiting the maximum over-pressure that can be obtained. When the pressure in CO2-PB reaches 100 MPa, the shockwave is about 4.25 MPa. As the distance increases, the peak value of the shockwave decays rapidly. As the dimensionless distance increases from 1 to 5, the dimensionless overpressure decreases from 1 to 0.23. Under the same blasting pressure, increasing the filling pressure and increasing the filling volume slightly reduce the initial pressure of the shockwave. In the shock stage, strong compression is formed on the surface of the shockwave, resulting in a higher peak pressure value. Meanwhile, the stable pressure is influenced by the target distance, blasting pressure, and CO2-PB length.

WITHDRAWN: Impact pressure characteristics of carbon dioxide phase transition fracturing technique

“…They discovered that, for short impact distances, the impact pressure signi cantly decreases as ambient pressure increases, while erosion volume and impact pressure also decrease as impact distance increases. In addition, the goal distance and beginning blast pressure set a limit on the peak pressure produced by the impact (Pu et al 2022). Considering SC-CO 2 impact action target distance (Cai et al 2022) and initial pressure as reference factors, it was found that the impact pressure decreases with the increase of distance, and the increase of initial pressure causes the increase of impact pressures (Wang et al 2014).…”

Impact Pressure Characteristics of Carbon Dioxide Phase Transition Fracturing Technique

“…Tian et al proposed the influence of ambient pressure and impact distance on SC–CO 2 jet pressure . They discovered that, for short impact distances, the impact pressure significantly decreases as ambient pressure increases, while erosion volume and impact pressure also decrease as impact distance increases . Cai et al used SC–CO 2 impact target distance and initial pressure as reference factors to study the relationship between impact pressure and distance through numerical simulation .…”

“… 31 They discovered that, for short impact distances, the impact pressure significantly decreases as ambient pressure increases, while erosion volume and impact pressure also decrease as impact distance increases. 32 Cai et al used SC–CO 2 impact target distance and initial pressure as reference factors to study the relationship between impact pressure and distance through numerical simulation. 33 It is concluded that the impact pressure decreases with the increase in distance, and the increase in initial pressure leads to an increase in impact pressure.…”