Effect of fracture dip angle on flow-thermal coupling of multi-fractured surrounding rocks in typical submarine metal mine

doi:10.16265/j.cnki.issn1003-3033.2023.10.0380

Abstract

Abstract:

In order to study the effects of fracture dip angle on the flow-thermal coupling of multi-fractured surrounding rocks, a model of flow-thermal coupling of multi-fractured surrounding rocks in metal mines was established with Sanshan Island submarine metal mine as the engineering background. COMSOL Multiphysics was used to simplify the dimensionality reduction of three-dimensional fracture. What's more, the influence of the fracture dip angle on the outlet flow rate and seepage velocity of the fracture in the seepage field was studied, as well as the heat transfer time, temperature distribution and fracture outlet temperature in the temperature field during the flow-thermal coupling process. The results show that the dip of discrete fractures have obvious control on the seepage and temperature field of surrounding rock. The seepage velocity of geothermal water shows an overall trend of first decreasing, then flowing steadily, and finally increasing with the increase of the distance from the inlet. As time goes on, the flow rate at the crack outlet shows a continuous decreasing trend. The farther the fractured surrounding rock is from the roadway, the higher the temperature is, and the isotherm distribution of surrounding rock near different fracture dip angles is obviously irregular.

Key words: fracture dip, submarine metal mine, multi-fractured surrounding rock, flow-thermal coupling, numerical simulation, seepage field

ZHANG Yongliang, QU Min, CHEN Shiqiang, MU Hongwei, SHAO Bing, FAN Wentao. Effect of fracture dip angle on flow-thermal coupling of multi-fractured surrounding rocks in typical submarine metal mine[J]. China Safety Science Journal, 2023, 33(10): 71-78.

Figures/Tables 10

Fig.1

Fig.2

Fig.3

Tab.1

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

Fig.9

References 17

[1]	成巧耘, 李波波, 李建华, 等. 支撑剂嵌入作用下煤岩裂隙压缩性及渗流特性[J]. 中国安全科学学报, 2021, 31(10):105-111. doi: 10.16265/j.cnki.issn1003-3033.2021.10.015
	CHENG Qiaoyun, LI Bobo, LI Jianhua, et al. Coal fracture's compressibility and permeability under proppant embedding[J]. China Safety Science Journal, 2021, 31(10):105-111. doi: 10.16265/j.cnki.issn1003-3033.2021.10.015
[2]	HUANG Ping, ZHANG Yongliang. Analysis of the flow regularity of the geothermal water seepage under the mining conditions of the singularity fracture of the deep rock mass[J]. Journal of Safety and Environment, 2017, 17(5):1820-1822.
[3]	邵玉龙, 姚池, 漆宾宾, 等. 三维复杂裂隙岩体渗流传热耦合的数值研究[J]. 地下空间与工程学报, 2021, 17(4):1063-1071.
	SHAO Yulong, YAO Chi, QI Binbin, et al. Numerical study on the coupling of seepage and heat transfer in 3D complex fractured rock masses[J]. Chinese Journal of Underground Space and Engineering, 2021, 17(4):1063-1071.
[4]	CHEN Liu, LI Jiangbo, ZHANG Yu, et al. Study on coupled heat transfer and seepage in large sparsely fractured surrounding rocks in deep underground spaces[J]. Applied Thermal Engineering, 2019:DOI:10.1016/j.applthermaleng.2019.114277.
[5]	李波波, 杨康, 徐鹏, 等. 力热耦合条件下煤岩渗透率模型研究[J]. 中国安全科学学报, 2017, 27(6):139-144. doi: 10.16265/j.cnki.issn1003-3033.2017.06.024
	LI Bobo, YANG Kang, XU Peng, et al. Research on model for permeability of coal under stress and temperature coupling condition[J]. China Safety Science Journal, 2017, 27(6):139-144. doi: 10.16265/j.cnki.issn1003-3033.2017.06.024
[6]	LUO Shuang, ZHAO Zhihong, PENG Huang, et al. The role of fracture surface roughness in macroscopic fluid flow and heat transfer in fractured rocks[J]. International Journal of Rock Mechanics and Mining Sciences, 2016, 87: 29-38. doi: 10.1016/j.ijrmms.2016.05.006
[7]	JAOUDE B I, NOVAKOWSKI K, KUEPER B. Identifying and assessing key parameters controlling heat transport in discrete rock fractures[J]. Geothermics, 2018, 75:93-104. doi: 10.1016/j.geothermics.2018.04.007
[8]	YAO Chi, SHAO Yulong, YANG Jianhua, et al. Effects of fracture density, roughness, and percolation of fracture network on heat-flow coupling in hot rock masses with embedded three-dimensional fracture network[J]. Geothermics, 2020: DOI:10.1061/(ASCE)GM.1943-5622.0001718.
[9]	LU Wei, XIANG Yanyong, TANG Chao. Model experiment and numerical simulation of flow and heat transfer for sand-filled fractured rock model[J]. Rock and Soil Mechanics, 2011, 32(11): 3448-3454.
[10]	WITHERSPOON A P, WANG Y S J, IWAI K, et al. Validity of Cubic Law for fluid flow in a deformable rock fracture[J]. Water Resources Research, 1980, 16(6):1016-1024. doi: 10.1029/WR016i006p01016
[11]	MIAO Tongjun, YU Boming, DUAN Yonggang, et al. A fractal analysis of permeability for fractured rocks[J]. International Journal of Heat and Mass Transfer, 2015, 81:75-80. doi: 10.1016/j.ijheatmasstransfer.2014.10.010
[12]	PARSONS R W. Permeability of idealized fractured rock[J]. Society of Petroleum Engineers Journal, 1966, 6(2):126-136. doi: 10.2118/1289-PA
[13]	ZHANG Yongliang, ZHANG Xilong, LI Min, et al. Research on heat transfer enhancement and flow characteristic of heat exchange surface in cosine style runner[J]. Heat and Mass Transfer, 2019, 55(11): 3117-3131. doi: 10.1007/s00231-019-02647-5
[14]	ZHANG Yongliang, HUANG Ping. Influence of mine shallow roadway on airflow temperature[J]. Arabian Journal of Geosciences, 2019, 13(24):DOI: 10.1007/s12517-019-4934-7.
[15]	HUANG Ping, HUANG Wei, ZHANG Yongliang, et al. Simulation study on sectional ventilation of long-distance high-temperature roadway in mine[J]. Arabian Journal of Geosciences, 2021, 14(16):1-9. doi: 10.1007/s12517-020-06304-8
[16]	CHEN Biguang, SONG Erxiang, CHENG Xiaohui. Numerical calculation method of discrete fracture model for two-dimensional fractured rock mass seepage and heat transfer[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(1):43-51.
[17]	FRANCO A, VACCARO M. Numerical simulation of geothermal reservoirs for the sustainable design of energy plants: a review[J]. Renewable and Sustainable Energy Reviews, 2014, 30:987-1002. doi: 10.1016/j.rser.2013.11.041

参数	数值	参数	数值
围岩孔隙率	0.1	裂隙孔隙率	0.3
围岩渗透率/ mD	2.1×10^-11	裂隙渗透率/ mD	1×10^-7
围岩密度/ (kg·m^-3)	2 550	地下水密度/ (kg·m^-3)	1 025
围岩比热容/ (J·(kg·K)^-1)	720	地下水比热容/ (J·(kg·K)^-1)	4 196
围岩导热系数/ (W· (m·K)^-1)	1.85	地下水动态黏度/(Pa·s)	1.04×10^-3
比热容率	1	地下水导热性/ (W·(m·K)^-1)	0.56