Damage and Breakage Characteristics of Loaded Coal Impacted by High-Pressure Pulse Water Jet and Its Influence Factors
-
摘要: 为揭示高压脉冲水射流喷嘴内外速度的演化规律及高压脉冲水射流冲击下受载煤岩的冲击破坏特征，基于SPH-FEM（smoothed particle hydrodynamics-finite element method）耦合算法，采用具有正弦函数特性的速度挤压管道内柱塞以实现水射流速度的周期性变化，获得了水射流速度在喷嘴内外的演化规律，对比分析了脉冲射流冲击下受载和非受载煤岩破坏特征的时序特性，揭示了平均速度、脉冲幅值及脉冲频率等关键参数对煤岩损伤破坏特征的影响规律。结果表明：水粒子在喷嘴内外的速度演化过程依次经历了管路中的静止阶段和瞬态突增的低速阶段、喷嘴收敛段的加速阶段、出口直线段的微加速阶段、出喷嘴后的正弦脉冲变速阶段4个阶段。无应力和二维应力加载工况下，煤岩的破碎坑分别呈畸形化发展和碗状向U形演变。二维应力加载工况下，煤岩内部裂纹的衍生及传播受到抑制，煤岩破碎效率降低，脉冲射流的破碎效率高于连续射流的破碎效率。随着柱塞平均速度、脉冲幅值的增大，受载煤岩的破碎深度和破碎面积均呈指数增大。随着脉冲频率的增加，受载煤岩的破碎深度和破碎面积均呈先增大后减小的变化趋势。存在破碎煤岩效果最优的脉冲频率。研究成果可为高压脉冲水射流破碎受载煤岩的效率提升和工艺参数优化等提供理论指导。Abstract: To elucidate the evolution laws of impact velocity of high-pressure pulse water jet and the breakage characteristics of coal under confining condition, a coupled smoothed particle hydrodynamics-finite element (SPH-FEM) algorithm is adopted. A sinusoidal velocity is applied to the plunger inside the pipeline. The evolution laws of water jet velocity inside and outside the nozzle were obtained, and the temporal damage and breakage characteristics of coal under load and unload conditions impacted by pulse water jet were compared and analyzed. The influence of key parameters such as average velocity, pulse amplitude, and pulse frequency on damage and breakage characteristics of coal was revealed. The results show that the velocity evolution of water jet particles inside and outside the nozzle undergoes four stages: a stationary stage and transient acceleration to a low speed in the pipeline, acceleration inside the convergent section of the nozzle, micro-acceleration inside the straight section of the nozzle, and pulse variation speed following a sinusoidal variation after exiting the nozzle. Under the stress free and two-dimensional stress load conditions, the broken pits of coal specimen exhibit an abnormal development, and undergoes from bowl shape to U-shape, respectively. Two-dimensional stress load has a suppressive effect on the derivation and propagation of internal cracks in coal, reducing the rock-breaking efficiency. Besides, pulse water jet has a higher rock-breaking efficiency on loaded coal specimens than that of continuous water jet. The depth and area of coal fragmentation increase exponentially with the increase of plunger’s average velocity or pulse amplitude, and show a trend of initial increase and subsequent decrease with the increase of pulse frequency, indicating the existence of an optimal pulse frequency for coal fragmentation. The research findings could provide a theoretical guidance for improving the rock-breaking efficiency of high-pressure pulse water jet under confining conditions and optimizing the working parameters.
-
Key words:
- pulse water jet /
- coal fragmentation /
- confining pressure /
- damage /
- breakage /
- influencing factors
-
图 2 高压脉冲水射流冲击受载煤岩的数值计算模型
Figure 2. Numerical calculation model for impact loaded coal specimen by high-pressure pulse water jet
图 4 喷嘴结构及特征粒子的位置分布
Figure 4. Nozzle structure and locations of characteristic particles
图 5 射流特征粒子运动速度随时间的变化曲线
Figure 5. Time-varying curves of velocity for characteristic particles in the jet flow
图 6 特征水粒子喷出速度演化曲线
Figure 6. Variations in ejection velocity of characteristic particle in jet flow
图 7 不同应力加载工况下射流作用煤岩损伤破坏云图
Figure 7. Cloud diagrams of damage and failure at different times of coal specimens subjected to water jets under different operating conditions
图 8 破碎坑深度及面积随冲击时间的变化关系
Figure 8. Change in depth and area of the fracture pit versus impact time
图 9 不同柱塞平均速度下受载煤岩的损伤破坏云图（t=180 μs）
Figure 9. Cloud diagrams of damage and failure of loaded coal specimens under different average velocities of plunger (t=180 μs)
图 10 破碎坑的深度和面积与柱塞平均速度的关系曲线
Figure 10. Relationships between the depth, area of the broken pits and the average velocity of the plunger
图 11 不同柱塞脉冲幅值下受载煤岩的损伤破坏云图 (t=180 μs)
Figure 11. Cloud diagrams of damage and failure of loaded coal specimens under different pulse amplitudes of plunger (t=180 μs)
图 12 破碎坑深度和面积与柱塞脉冲幅值的关系曲线
Figure 12. Relationships between the depth, area of the broken pits and the plunger pulse amplitude
图 13 不同柱塞脉冲频率下煤岩的损伤破坏云图
Figure 13. Cloud diagrams of damage and failure of loaded coal specimens under different pulse frequencies of plunger
图 14 破碎坑深度和面积与柱塞脉冲频率的关系曲线
Figure 14. Relationships between the depth, area of the broken pits and pulse frequency of plunger
表 1 水射流本构模型参数
Table 1. Constitutive model parameters of water jet
ρ0/(g·cm−3) C/(m·s−1) S1 S2 S3 α γ0 E/J 1.05 1480 2.56 −1.98 0.29 1.40 0.49 0 
下载: 导出CSV
表 2 煤岩的RHT模型参数
Table 2. RHT model parameters of coal
ρr/(kg·m−3) G/GPa fc/MPa α0/% $ F_{\text{t}}^* $/MPa pcrush/MPa D1 D2 1840 12.3 20 1 0.27 25.67 0.04 1
下载: 导出CSV
-
[1] KARACAN C Ö, RUIZ F A, COTÈ M, et al. Coal mine methane: a review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction [J]. International Journal of Coal Geology, 2011, 86(2/3): 121–156. [2] ZHANG P, MENG Z P, JIANG S, et al. Characteristics of in-situ stress distribution in Zhengzhuang Region, Southern Qinshui Basin, China and its stress path during depletion [J]. Engineering Geology, 2020, 264: 105413. doi: 10.1016/j.enggeo.2019.105413 [3] GE Z L, CAO S R, LU Y Y, et al. Fracture mechanism and damage characteristics of coal subjected to a water jet under different triaxial stress conditions [J]. Journal of Petroleum Science and Engineering, 2022, 208: 109157. doi: 10.1016/j.petrol.2021.109157 [4] HUANG F, MI J Y, LI D, et al. Comparative investigation of the damage of coal subjected to pure water jets, ice abrasive water jets and conventional abrasive water jets [J]. Powder Technology, 2021, 394: 909–925. doi: 10.1016/j.powtec.2021.08.079 [5] GE Z L, SHANGGUAN J M, ZHOU Z, et al. Investigation of fracture damage and breaking energy consumption of hard rock repeatedly cut by abrasive water jet [J]. Rock Mechanics and Rock Engineering, 2023, 56(4): 3215–3230. doi: 10.1007/s00603-023-03230-5 [6] FOLDYNA J, SITEK L, ŠVEHLA B, et al. Utilization of ultrasound to enhance high-speed water jet effects [J]. Ultrasonics Sonochemistry, 2004, 11(3/4): 131–137. [7] HLOCH S, ADAMČÍK P, NAG A, et al. Hydrodynamic ductile erosion of aluminium by a pulsed water jet moving in an inclined trajectory [J]. Wear, 2019, 428/429: 178–192. doi: 10.1016/j.wear.2019.03.015 [8] DEHKHODA S, HOOD M. An experimental study of surface and sub-surface damage in pulsed water-jet breakage of rocks [J]. International Journal of Rock Mechanics and Mining Sciences, 2013, 63: 138–147. doi: 10.1016/j.ijrmms.2013.08.013 [9] LIU Y, WEI J P, REN T, et al. Experimental study of flow field structure of interrupted pulsed water jet and breakage of hard rock [J]. International Journal of Rock Mechanics and Mining Sciences, 2015, 78: 253–261. doi: 10.1016/j.ijrmms.2015.06.005 [10] RAJ P, CHATTOPADHYAYA S, MONDAL A. A review on continuous and pulsed water jet machining [J]. Materials Today: Proceedings, 2020, 27: 2596–2604. doi: 10.1016/j.matpr.2019.11.071 [11] LI H S, LIU S Y, ZHOU F Y, et al. Experimental investigation on concrete rock breaking performance of self-excited oscillation pulsed waterjet [J]. Engineering Fracture Mechanics, 2022, 268: 108502. doi: 10.1016/j.engfracmech.2022.108502 [12] POLYAKOV A, ZHABIN A, AVERIN E, et al. Generalized equation for calculating rock cutting efficiency by pulsed water jets [J]. Journal of Rock Mechanics and Geotechnical Engineering, 2019, 11(4): 867–873. doi: 10.1016/j.jrmge.2018.11.009 [13] ZHANG J C, ZHANG B, LIU B, et al. Investigation on the influence of the frequency of pulsed water jet on the rock-breaking effect [J]. Powder Technology, 2024, 431: 119054. doi: 10.1016/j.powtec.2023.119054 [14] STOXREITER T, MARTIN A, TEZA D, et al. Hard rock cutting with high pressure jets in various ambient pressure regimes [J]. International Journal of Rock Mechanics and Mining Sciences, 2018, 108: 179–188. doi: 10.1016/j.ijrmms.2018.06.007 [15] 金兵. 受载条件下高压水射流冲击破岩实验及煤层增透应用研究 [D]. 北京: 煤炭科学研究总院, 2019.JIN B. Study on rock-breaking experiment by high-pressure water jet under confining pressure and its application in coal seam permeability [D]. Beijing: China Coal Research Institute, 2019. [16] 曹世荣. 真三轴条件下水射流冲击深部煤岩破裂特征及损伤机理 [D]. 重庆: 重庆大学, 2022.CAO S R. Fracture characteristics and damage mechanism of deep coal impacted by water jet under true triaxial stress [D]. Chongqing: Chongqing University, 2022. [17] XIAO S Q, XIAO J C, REN Q Y, et al. Investigation on rock breakage by high-velocity water jet impact under different stress loading conditions: fracture characteristic, stress and damage evolution laws [J]. Powder Technology, 2024, 433: 119287. doi: 10.1016/j.powtec.2023.119287 [18] REN F S, FANG T C, CHENG X Z. Study on rock damage and failure depth under particle water-jet coupling impact [J]. International Journal of Impact Engineering, 2020, 139: 103504. doi: 10.1016/j.ijimpeng.2020.103504 [19] XIAO S Q, XIAO J C, REN Q Y, et al. Damage evolution and fracture characteristics of heterogeneous concrete with coarse aggregate impacted by high-velocity water jet [J]. Construction and Building Materials, 2024, 416: 135128. doi: 10.1016/j.conbuildmat.2024.135128 [20] JIANG H X, LIU Z H, GAO K D. Numerical simulation on rock fragmentation by discontinuous water-jet using coupled SPH/FEA method [J]. Powder Technology, 2017, 312: 248–259. doi: 10.1016/j.powtec.2017.02.047 [21] MA L, BAO R H, GUO Y M. Waterjet penetration simulation by hybrid code of SPH and FEA [J]. International Journal of Impact Engineering, 2008, 35(9): 1035–1042. doi: 10.1016/j.ijimpeng.2007.05.007 [22] YU R, DONG X W, LI Z L, et al. SPH-FEM simulation of concrete breaking process due to impact of high-speed water jet [J]. AIP Advances, 2021, 11(4): 045226. doi: 10.1063/5.0049213 [23] LIU X H, LIU S Y, JI H F. Numerical research on rock breaking performance of water jet based on SPH [J]. Powder Technology, 2015, 286: 181–192. doi: 10.1016/j.powtec.2015.07.044 [24] 李洪盛. 自激振荡脉冲射流破岩性能研究 [D]. 徐州: 中国矿业大学, 2020.LI H S. Rock breaking performance of self-excited oscillating pulsed water jet [D]. Xuzhou: China University of Mining & Technology, 2020. [25] 周维. 自激振荡脉冲射流破岩特性数值模拟 [D]. 重庆: 重庆大学, 2014.ZHOU W. The numerical simulation of rock breaking characteristics under self-excited oscillation pulsed jet [D]. Chongqing: Chongqing University, 2014. [26] 林晓东, 卢义玉, 汤积仁, 等. 前混合式磨料水射流磨料粒子加速过程数值模拟 [J]. 振动与冲击, 2015, 34(16): 19–24, 47.LIN X D, LU Y Y, TANG J R, et al. Numerical simulation of abrasive particles acceleration process in pre-mixed abrasive water jet [J]. Journal of Vibration and Shock, 2015, 34(16): 19–24, 47. [27] XIAO S Q, QIN H X, ZHANG W F, et al. On the concrete breakage by pulsed water jet impact: fracture characteristic, stress and damage evolution laws [J]. Case Studies in Construction Materials, 2023, 19: e02634. doi: 10.1016/j.cscm.2023.e02634 -
下载:
点击查看大图
计量
- 文章访问数: 19
- HTML全文浏览量: 12
- PDF下载量: 0
