Experimental study of flow field structure of interrupted pulsed water jet and breakage of hard rock

Liu, Yong; Wei, Jianping; Ren, Ting X; Lu, Zhanwu

doi:10.1016/j.ijrmms.2015.06.005

Cited by 53 publications

(13 citation statements)

References 11 publications

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“…It is clear that the thermodynamic parameters (e.g., p, T, and ρ) of the gas jet depend on the changes of nozzle section. Thus, these parameters can be calculated by nozzle section area based on (8), (9), and (10). To optimize the nozzle structure, the way the ratio of the nozzle section area affects the thermodynamics parameter should be figured out first.…”

Section: Geofluidsmentioning

confidence: 99%

“…To date, researchers have used the technology for rock or coal breakage in coal-bed methane exploration [4][5][6]. As a nonliquid invasive jet, the abrasive gas jet avoids borehole collapse, which is mainly induced by water invasion during assisted drilling with high-pressure water jets [7][8][9]. Like supercritical CO 2 , the abrasive gas jet has great potential for assisted drilling and perforation in coal-bed methane exploration [10].…”

Section: Introductionmentioning

confidence: 99%

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Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage

Liu

Zhang

et al. 2018

Geofluids

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Abrasive gas jet technologies are efficient and beneficial and are widely used to drill metal and glass substrates. When the inlet pressure is increased, gas jets could be powerful enough to break rock. They have potential uses in coal-bed methane exploration and drilling because of their one-of-a-kind nonliquid jet drilling, which avoids water invasion and borehole collapse. Improving the efficiency of rock breakage using abrasive gas jets is an essential precondition for future coal-bed methane exploration. The nozzle structure is vital to the flow field and erosion rate. Furthermore, optimizing the nozzle structure for improving the efficiency of rock breakage is essential. By combining aerodynamics and by fixing the condition of the nozzle in the drill bit, we design four types of preliminary nozzles. The erosion rates of the four nozzles are calculated by numerical simulation, enabling us to conclude that a nozzle at Mach 3 can induce maximum erosion when the pressure is 25 MPa. Higher pressures cannot improve erosion rates because the shield effect decreases the impact energy. Smaller pressures cannot accelerate erosion rates because of short expansion waves and low velocities of the gas jets. An optimal nozzle structure is promoted with extended expansion waves and less obvious shield effects. To further optimize the nozzle structure, erosion rates at various conditions are calculated using the single-variable method. The optimal nozzle structure is achieved by comparing the erosion rates of different nozzle structures. The experimental results on rock erosion are in good agreement with the numerical simulations. The optimal nozzle thus creates maximum erosion volume and depth.

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Section: Geofluidsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage

Liu

Zhang

et al. 2018

Geofluids

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“…Pulsed water jet is a kind of water jet acting on the target in the form of pulse, which can make the rock produce tensile, shear and fatigue damage under low jet pressure, and form macro cracks that lead to volume fracture by effectively applying the water-hammer effect of the jet to the target, the stress wave under the impact and the pulsed cyclic shock [7][8][9]. Research results show that the erosion ability of pulsed jet is significantly higher than that of continuous water jet under the same pressure, and the specific energy consumption is lower [10][11].…”

Section: Introductionmentioning

confidence: 99%

The Formation Principle and Characteristics of Self-supercharging Pulsed Water Jet

Ling

Tang³

et al. 2020

Preprint

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High-pressure pulsed water jet technology has high development potential in the field of rock fragmentation. Technical bottlenecks such as difficulty in pressurization and inconvenient frequency adjustment for existing types of pulsed jets, a self-supercharging pulsed water jet generation method is proposed based on the theory of pulsed water jet and principle of hydraulic boosting, which changes the flow direction of fluid medium through the valve core to make the piston reciprocate in the cylinder, and relies on the effective area difference between the front and rear chambers in the stroke stage of the piston to realize the organic combination of “pulse” and “supercharging” of the jet, so as to self-supercharging pulsed water jet. Based on revealing the formation principle of self-supercharging pulsed jet, the self-supercharging pulsed jet generation system was designed, and the self-supercharging pulsed jet testing platform was built, many groups of pressure collection and jet shape observation experiments were carried out for different operating parameters. The research results show that both the jet pressure and the jet shape show periodic change, and higher pulse pressure can be obtained at lower inlet pressure. The error of the pressure ratio calculated according to the experimental results is less than 3% compared with the theoretical design value, thus verifying the feasibility of the method . Pulse pressure and pulse frequency are controllable, that is, as the inlet flow rate increases in the stroke phase of the piston, the pulse pressure and pulse frequency increase, and the pulse duration decreases, as the inlet flow rate increase in the backward stroke phase of the piston, the pulse frequency increases, and the pulse pressure and pulse duration remain unchanged. The research results lay the foundation for enriching the theory of pulsed jet generation and expanding its application range.

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“…These are the cavitating waterjet, pulsed waterjet, self-resonating waterjet (SRWJ), and the abrasive waterjet. Each of these has much stronger impact power and higher working efficiency than the conventional plain waterjet under the same operating conditions [5][6][7]. The SRWJ has the advantages of both a cavitating waterjet and a pulsed waterjet, and thus has attracted the attention of a number of researchers [8,9].…”

Section: Introductionmentioning

confidence: 99%

Effects of Nozzle Exit Angle on the Pressure Characteristics of SRWJs Used for Deep-Hole Drilling

Wang

Miao

et al. 2019

Applied Sciences

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The self-resonating waterjet (SRWJ) has been applied in petroleum, natural gas, and mining engineering ever since its strong erosion ability in deep-hole drilling was recognized. Aiming at further improving the working efficiency of SRWJs, the effects of the exit angle of the organ-pipe nozzle on the axial pressure oscillations of the jet were experimentally studied. Six exit angles of θ = 0°, 30°, 45°, 60°, 75°, and 90° were employed in the experiment, and the axial pressure oscillation peak (Pmax) and amplitude (Pa) were used for characterizing the performance of SRWJs. It was found that the exit angle greatly affects the axial pressure oscillations, including the development trends against the standoff distance and the magnitudes of Pmax and Pa. Under testing with two inlet pressures, the exit angle of θ = 0° always resulted in the greatest Pmax and Pa within the range of the testing standoff distance. With the increase of standoff distance, both Pmax and Pa first increased and then decreased when the exit angle was 0°; while they kept decreasing when the exit angle was 30°, 45°, 60°, 75°, and 90°. Moreover, the exit angles of θ = 90° and 60°, corresponding to inlet pressures of Pi = 10 MPa and 20 MPa, led to both the minimum magnitudes of Pmax and Pa under the experimental conditions. The results also indicate that the exit angle affects the interactions between the nozzle lip and the jet and help provide information for improving the working efficiency of SRWJs in practical applications.

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Experimental study of flow field structure of interrupted pulsed water jet and breakage of hard rock

Cited by 53 publications

References 11 publications

Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage

Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage

The Formation Principle and Characteristics of Self-supercharging Pulsed Water Jet

Effects of Nozzle Exit Angle on the Pressure Characteristics of SRWJs Used for Deep-Hole Drilling

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