THERMAL SCIENCE

International Scientific Journal

Shan-Jie Su

,

Feng Gao

,

Cheng-Zheng Cai

,

Meng-Lin Du

,

Ze-Kai Wang

EFFECT OF LOW TEMPERATURE DAMAGE ON TENSILE STRENGTH OF COAL UNDER THE LIQUID NITROGEN FREEZING

ABSTRACT
To explore the influence of low temperature damage on the tensile strength of coal under the liquid nitrogen freezing, the Brazilian splitting tests are conducted on the bedding coal in this paper. The tensile strength, macro fracture surface morphology, failure path and micro-structures of the coal samples before and after liquid nitrogen treatment were analyzed systematically. The results show that the tensile strength of coal after liquid nitrogen freezing is reduced, the macro fracture surfaces with greater roughness or fractal dimension were induced in the coal treated by liquid nitrogen freezing during the Brazilian splitting tests, the opening and number of the failure paths of coal after liquid nitrogen freezing increase significantly, and the microscopically, the bedding and matrix structures of coal are destroyed due to the temperature stress caused by large temperature difference between the liquid nitrogen and coal matrix.
KEYWORDS
liquid nitrogen, roughness, fractal dimension, coal, tensile strength
PAPER SUBMITTED: 2020-04-26
PAPER REVISED: 2020-07-25
PAPER ACCEPTED: 2020-08-07
PUBLISHED ONLINE: 2020-11-27
DOI REFERENCE: https://doi.org/10.2298/TSCI2006979S
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2020, VOLUME 24, ISSUE Issue 6, PAGES [3979 - 3986]
REFERENCES
  1. Hao, C. M., et al., A Novel Technology for Enhancing Coalbed Methane Extraction: Hydraulic Cavitating Assisted Fracturing, Journal of Natural Gas Science and Engineering, 72 (2019), Dec., 103040
  2. Colmenares, L. B., et al., Hydraulic Fracturing and Wellbore Completion of Coalbed Methane Wells in the Powder River Basin, Wyoming: Implications for Water and Gas Production, AAPG Bulletin, 91 (2007), 1, pp. 51-67
  3. Van, G., et al., Propellant-Assisted Perforating in Tight-Gas Reservoirs: Wireline Formation Tests Show Successful Stimulation, International Oil and Gas Conference and Exhibition in China, Beijing, China, June, (2010), pp. 8-10
  4. Pelak, A. J., et al., Surface Water Geochemical and Isotopic Variations in an Area of Accelerating Marcellus Shale Gas Development, Environmental Pollution, 195 (2014), C, pp. 91-100
  5. Anderson, R. L., et al., Clay Swelling-A Challenge in the Oilfield, Earth Sci, 98 (2009), 3-4, 201e216
  6. Xue, Y., et al., Productivity Analysis of Fractured Wells in Reservoir of Hydrogen and Carbon Based on Dual-Porosity Medium Model, International Journal of Hydrogen Energy, 45 (2020), 39, pp. 20240-20249
  7. Liu, J., et al., Numerical Evaluation on Multiphase Flow and Heat Transfer during Thermal Stimulation Enhanced Shale Gas Recovery, Applied Thermal Engineering, 178 (2020), Sept., 115554
  8. Zhang, Y., et al., The Application of Short-Wall Block Backfill Mining to Preserve Surface Water Resources in Northwest China, Journal of Cleaner Production, 261 (2020), July, 121232
  9. Qin, L., et al., Changes in the Petrophysical Properties of Coal Subjected to Liquid Nitrogen Freeze-Thaw - A Nuclear Magnetic Resonance Investigation, Fuel, 194 (2017), Apr., pp. 102-114
  10. Sandstrom, T., et al., The Influence of Temperature on Water Absorption in Concrete during Freezing, Nordic Concrete Research, 45 (2012), 1, pp. 45-58
  11. Cha, M. S., et al., Cryogenic Fracturing for Reservoir Stimulation-Laboratory Studies, Journal of Petroleum Science and Engineering, 124 (2014), Dec., pp. 436-450
  12. McDaniel, B. W., et al., Field Applications of Cryogenic Nitrogen as a Hydraulic Fracturing Fluid, Proceedings, SPE Annual Technical Conference and Exhibition Delta, Denver, Col., USA, 1997, pp. 561-572
  13. Cai, C. Z., et al., Experimental Study of the Effect of LN2 Cooling on Rock Pore Structure, Journal of Natural Gas Science and Engineering, 21 (2014), Nov., pp. 507-517
  14. Tran, D., et al., Initiation and Propagation of Secondary Cracks in Thermo-Poroelastic Media, Proceedings, 46th US Rock Mechanics/Geomechanics Symposium, American Rock Mechanics Association, Chicago, Ill., USA, 2012
  15. Guo, X. K., LN2 Semi Submersion Coal on Fracturing and Increase Permeability of Test Study (in Chinese), M. Sc. thesis, Hebei University of Science and Technology, Hebei, China, 2016
  16. Qin, L., et al., Failure Mechanism of Coal after Cryogenic Freezing with Cyclic Liquid Nitrogen and Its Influences on Coalbed Methane Exploitation, Energy & Fuels, 30 (2016), 10, pp. 8567-8578
  17. Zhou, H. W., et al., Direct Estimation of the Fractal Dimensions of a Fracture Surface of Rock, Surf Rev Lett, 10 (2008), 5, pp.751-762
  18. Ai, T, et al., Box-Counting Methods to Directly Estimate the Fractal Dimension of a Rock Surface, Appl Surf Sci, 314 (2014), Sept., pp. 610-621
PDF VERSION [DOWNLOAD]
Effect of low temperature damage on tensile strength of coal under the liquid nitrogen freezing

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence