Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage

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-k...

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Main Authors: Yong Liu, Juan Zhang, Tao Zhang, Huidong Zhang
Format: Article
Language:English
Published: Wiley 2018-01-01
Series:Geofluids
Online Access:http://dx.doi.org/10.1155/2018/9457178
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author Yong Liu
Juan Zhang
Tao Zhang
Huidong Zhang
author_facet Yong Liu
Juan Zhang
Tao Zhang
Huidong Zhang
author_sort Yong Liu
collection DOAJ
description 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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institution Kabale University
issn 1468-8115
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language English
publishDate 2018-01-01
publisher Wiley
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series Geofluids
spelling doaj-art-5817f9517dac4f80b6d80b178df97a362025-02-03T05:54:01ZengWileyGeofluids1468-81151468-81232018-01-01201810.1155/2018/94571789457178Optimal Nozzle Structure for an Abrasive Gas Jet for Rock BreakageYong Liu0Juan Zhang1Tao Zhang2Huidong Zhang3State Key Laboratory Cultivation Base for Gas Geology and Gas Control, Henan Polytechnic University, Jiaozuo, 454000 Henan, ChinaState Key Laboratory Cultivation Base for Gas Geology and Gas Control, Henan Polytechnic University, Jiaozuo, 454000 Henan, ChinaState Key Laboratory Cultivation Base for Gas Geology and Gas Control, Henan Polytechnic University, Jiaozuo, 454000 Henan, ChinaState Key Laboratory Cultivation Base for Gas Geology and Gas Control, Henan Polytechnic University, Jiaozuo, 454000 Henan, ChinaAbrasive 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.http://dx.doi.org/10.1155/2018/9457178
spellingShingle Yong Liu
Juan Zhang
Tao Zhang
Huidong Zhang
Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage
Geofluids
title Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage
title_full Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage
title_fullStr Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage
title_full_unstemmed Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage
title_short Optimal Nozzle Structure for an Abrasive Gas Jet for Rock Breakage
title_sort optimal nozzle structure for an abrasive gas jet for rock breakage
url http://dx.doi.org/10.1155/2018/9457178
work_keys_str_mv AT yongliu optimalnozzlestructureforanabrasivegasjetforrockbreakage
AT juanzhang optimalnozzlestructureforanabrasivegasjetforrockbreakage
AT taozhang optimalnozzlestructureforanabrasivegasjetforrockbreakage
AT huidongzhang optimalnozzlestructureforanabrasivegasjetforrockbreakage