Numerical Study on Collection and Environmental Disturbance Characteristics of Different Nodule Collecting Models

doi:10.16183/j.cnki.jsjtu.2023.023

Abstract

Abstract:

It is a significant technical challenge to exploit deep-sea polymetallic nodules with high efficiency and low disturbance. The mechanical behavior of seabed nodule collecting is very complicated, which is a multi-physical coupling process involving three-dimensional turbulent flow, discrete particle movement, and fine particle soil failure. In this paper, three main deep-sea hydraulic nodule collecting methods, i.e., the suck-up-based method, the Coandă-effect-based method, and the double-jet hydraulic method, are investigated by numerical simulation on the performance of nodule collecting and environmental disturbance. The realizable K-Epsilon two-layer model and the discrete element method are used to simulate the turbulent flow of the liquid phase and nodule particles in the solid phase respectively. The effect of collection flow q_m and drag velocity v on collection rate η, turbulent kinetic energy k, and volume fraction φ of the seawater-sediment mixture in the collecting flow field is analyzed. The flow velocity, pressure, and nodule distribution are explored. The results indicate that, at the same q_m and v, the double-jet hydraulic model will achieve the largest η, while the suck-up-based model will achieve the least η. The double-jet hydraulic model has the most significant disturbance to the near-bottom flow field and the most obvious sediment spreading phenomenon. In contrast, the suck-up-based model and the Coandăeffect-based model have less environmental disturbance, which is more conducive to the requirements of environmental protection. The Coandă-effect-based model shows minor sensitivity to q_m and v and a good balance between high nodule collecting efficiency and low environmental disturbance. This paper will provide a scie.pngic basis for revealing the nodule collecting mechanism and designing and developing a nodule collecting device.

Key words: deep-sea mining, polymetallic nodules, multi-field coupling of fluid-solid-soil, nodule collection efficiency, environmental disturbance

CLC Number:

P751

LI Yuyao, ZHAO Guocheng, XIAO Longfei. Numerical Study on Collection and Environmental Disturbance Characteristics of Different Nodule Collecting Models[J]. Journal of Shanghai Jiao Tong University, 2024, 58(7): 1036-1046.

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References 18

[1]	ALVARENGA R A F, PRÉAT N, DUHAYON C, et al. Prospective life cycle assessment of metal commodities obtained from deep-sea polymetallic nodules[J]. Journal of Cleaner Production, 2022, 330: 1-10.
[2]	邱显焱. 深海采矿系统扬矿子系统纵向振动被动减振研究[D]. 长沙: 中南大学, 2014.
	QIU Xianyan. Research for passive control for longitudinal vibration of lifting pipe in deep sea mining system[D]. Changsha: Central South University, 2014.
[3]	ELERIAN M, VAN R C, HELMONS R. Experimental and numerical modelling of deep-sea-mining-generated turbidity currents[J]. Minerals, 2022, 12(5): 1-23.
[4]	夏建新, 吴优, 邹燚, 等. 基于PIV技术粗颗粒在管流断面浓度分布试验研究[J]. 应用基础与工程科学学报, 2017, 25(6): 1086-1093.
	XIA Jianxin, WU You, ZOU Yi, et al. Experimental study on the concentration distribution in pipe flow based on PIV technology[J]. Journal of Basic Science and Engineering, 2017, 25(6): 1086-1093.
[5]	赵国成, 肖龙飞, 杨建民, 等. 深海水力集矿球形颗粒受力特性试验研究[J]. 上海交通大学学报, 2019, 53(8): 907-912.
	ZHAO Guocheng, XIAO Longfei, YANG Jianmin, et al. Experimental research on force characteristics of a spherical particle in deep sea hydraulic collecting[J]. Journal of Shanghai Jiao Tong University, 2019, 53(8): 907-912.
[6]	XIONG H, CHEN Y, YANG N, et al. Numerical study on settling and floating movements of a sphere particle flowing in a vertical pipe[C]//The 28th International Ocean and Polar Engineering Conference. Sapporo, Japan:The 28th International Ocean and Polar Engineering Conference, 2018: 176-182.
[7]	LIM S J, KIM J W, JUNG S T, et al. Deep-seawater flow characteristics around the manganese nodule collecting device[J]. Procedia Engineering, 2015, 116: 544-551.
[8]	CHO S, PARK S, OH J, et al. Design optimization of deep-seabed pilot miner system with coupled relations between constraints[J]. Journal of Terramechanics, 2019, 83: 25-34.
[9]	YANG N, TANG H. Several considerations of the design of the hydraulic pick-up device[J]. Environmental Health Perspectives, 2003, 32(11): 267-271.
[10]	HONG S, CHOI J S, KIM J H, et al. A note on design and operation of waterjet nodule lifter of manganese nodule collector[J]. International Journal of Offshore and Polar Engineering, 2001, 11(3): 237-239.
[11]	黎蔚杰, 张琪, 廖晨聪, 等. 孤立波和海流作用下单桩基础局部冲刷及保护的数值分析[J]. 上海交通大学学报, 2021, 55(6): 631-637. doi: 10.16183/j.cnki.jsjtu.2020.108
	LI Weijie, ZHANG Qi, LIAO Chencong, et al. Numerical analysis of local scour and protection of a single pile around a seabed under solitary wave and current[J]. Journal of Shanghai Jiao Tong University, 2021, 55(6): 631-637.
[12]	CHEN X, LIU X, LI H, et al. Effects of seabed geotechnical properties on scour mechanism at the pile in non-cohesive soils: Experimental study[J]. Ocean Engineering, 2022, 254: 1-15.
[13]	DURDEN J M, MURPHY K, JAECKEL A, et al. A procedural framework for robust environmental management of deep-sea mining projects using a conceptual model[J]. Marine Policy, 2017, 84: 193-201.
[14]	SHIH T H, LIOU W W, SHABBIR A, et al. A new k-ε eddy viscosity model for high Reynolds number turbulent flows[J]. Computers & Fluids, 1995, 24(3): 227-238.
[15]	徐泳, 孙其诚, 张凌, 等. 颗粒离散元法研究进展[J]. 力学进展, 2003, 33(2): 251-260.
	XU Yong, SUN Qichen, ZHANG Ling, et al. Advances in discrete element methods for particulate materials[J]. Advances in Mechanics, 2003, 33(2): 251-260.
[16]	KAUFMAN R, LATIMER J P, TOLEFSON D C. The design and operation of a pacific ocean deep-ocean mining test ship: R/V Deepsea Minner II[C]//Offshore Technology Conference. Houston, Texas, USA: Offshore Technology Conference, 1985: 33-43.
[17]	HONG S, CHOI J S, KIM J H, et al. Experimental study on hydraulic performance of hybrid pick-up device of manganese nodule collector[C]//The 3rd ISOPE Ocean Mining Symposium. Goa, India: The Third ISOPE Ocean Mining Symposium, 1999: 69-77.
[18]	HU J, ZHAO G, XIAO L, et al. Experimental investigation on characteristics of flow field in ‘Suck-up-based’ and ‘Coandă-Effect-based’ nodule pick-up devices[C]//The 30th International Ocean and Polar Engineering Conference. Virtual:The 30th International Ocean and Polar Engineering Conference, 2020: 34-44.

参数	取值
ρ/(kg·m^-3)	1 025
μ/(Pa·s)	1.08×10^-3
沉积物-海水混合物密度,ρ_m/(kg·m^-3)	1 400
d/mm	20
矿粒密度,ρ_n/(kg·m^-3)	2 100
A_n/(kg·m^-2)	5.864
集矿头离底高度,h/m	0.03
集矿范围宽度,w/m	0.3

集矿模型	分析参数	网格数	时间步长/s	q_m_n/ (kg·s^-1)
吸扬式	网格收敛性分析	1 216 892	0.05	0.171 008
		1 375 034	0.05	0.174 044
		1 561 169	0.05	0.177 083
		2 082 416	0.05	0.180 143
		2 837 573	0.05	0.181 357
	时间步长收敛性分析	2 082 416	0.06	0.177 987
		2 082 416	0.05	0.180 143
		2 082 416	0.04	0.181 370
		2 082 416	0.03	0.181 452
		2 082 416	0.02	0.181 604
附壁射流式	网格收敛性分析	1 582 651	0.05	0.176 716
		1 906 052	0.05	0.179 113
		2 238 371	0.05	0.180 306
		2 376 212	0.05	0.180 706
		2 526 408	0.05	0.181 037
		2 777 746	0.05	0.181 384
	时间步长收敛性分析	2 238 371	0.06	0.178 097
		2 238 371	0.05	0.180 306
		2 238 371	0.04	0.181 666
		2 238 371	0.03	0.182 000
		2 238 371	0.02	0.182 149
射流冲采式	网格收敛性分析	253 143	0.05	0.166 392
		582 205	0.05	0.177 978
		1 114 108	0.05	0.183 515
		1 847 882	0.05	0.184 726
	时间步长收敛性分析	1 847 882	0.06	0.183 722
		1 847 882	0.05	0.184 263
		1 847 882	0.04	0.184 726
		1 847 882	0.03	0.184 982

集矿头种类	环境条件	颗粒状态	v/(m·s^-1)	q_m/ (t·s^-1)
吸扬式	清水	多颗粒	0.05,0.15,0.25	0~85
附壁射流式			0.05,0.15,0.25	0~70
射流冲采式			0.05,0.15,0.25	0~65
吸扬式	海水-沉积物	多颗粒(半埋态)	0.15	0~85
附壁射流式			0.15	0~80
射流冲采式			0.15	0~75