Design and Strength Analysis of A Spherical Connector for Lifting Subsystem in Deep Sea Mining System

A flexible connector of lifting pipes in a deep sea mining system is designed. The buttress thread （ based on API standard） is used and foreign experience in connector design is referred to. With this kind of connector, the lifting pipe wiU only bear the axial force, free of moment. The strength of the connector is analyzed in detail, including the connecting strength of the buttress thread, the dynamic load of the pipe system, pressures inside and outside of the pipe, the lateral stress of the pipe wall and so on. Especially, a geometric model is built for 3-D contact stress analysis. The distribution graph of contact stress is presented. It is indicated that the strength of the spherical connector meets the demand.

Experiment and Simulation for Articulated Lifting Subsystem of 1000 m Deep Sea Mining System

The experiment system of 1000 m deep sea mining system is built up with the similarity theory. Sine mechanism is used to simulate mining ship to generate lateral shock excitation by ocean wave. Simulation and experiment of spherical joint connecting deep sea mining system has been done in band six marine conditions. The results indicate that the moment of spherical joint connecting deep sea mining is smaller than that of the thread connected ones, the lifting pipe of sphelical joint is ＂flexible pipe＂. The flexural torque of the articulated lifting pipe system in pump and buffer is generally periodic variation with some irregularity, the value is stable on 60 N·S, and it is obviously smaller than that of the fixed lifting pipe system; The total displacement exhibits cyclic variation pattern, and the periodicity of them is longer than that of sea current. The results of experiment and simulation are basically consistent. And the analysis in the paper offers theoretical foundation of 1000 m deep sea mining system in China.

Experimental research on grouser traction of deep-sea mining machine

The traction characteristics of the grouser, cutting the simulative soil of deepsea sediment, with different tooth widths, tooth heights, and ground pressures are studied with traction characteristic test apparatus. A traction-displacement model is obtained by combining the analysis of the cutting mechanism. The results show that the tractiondisplacement curves of grousers with different tooth widths, tooth heights, and ground pressures have the same changing trend, which matches the Wong traction model. Their sensitivity coefficient and shear modulus are slightly fluctuated. Therefore, the average values can be used as the traction model parameters. The maximum traction of the grouser with a two-side edge and a 10 mm tooth width increment changing with the tooth height and ground pressure can be determined according to the grousers with different tooth widths. By combining the traction model parameters, the traction-displacement curve of the grouser with a certain group values of tooth width, tooth height, and ground pressure can be predicted. Therefore, the slip of the mining machine can be prevented to improve the mining efficiency.

Theoretical analysis of effect of solid phase on cavitation performance of deep-sea mining pump

In view of the present situation of low cavitation performance of deep-sea mining slurry pump, the effect of solid phase on the cavitation performance of deep-sea mining pump is analyzed theoretically. The relationship between gas and liquid phases are established by cavitation nucleon theory and mass energy equation as well as solid phase and liquid phase, and then we explored the relationship between gas phase and solid phase. The results show that the critical bubble radius and solid-phase concentration flow rate during the cavitation can be related to the liquid pressure. Eq.(19) show that the larger the solid particle concentration and the solid phase flow, the earlier the cavitation will occur, and pump anti-cavitation performance will decline.

Future Trends of Deep Sea Bed Mining Technology

The present status of deep sea bed mining technology for polymetallic nodules has been critically examined in light of its history of development the UNCLoS (the United Nation Convention on the Law of the Sea) regime and the current trends in research.The critical technologies have been highlighted and the need for system integration underscored. The deep sea bed environment and the engineering challenge were presented and the necessary features of the deep sea bed mining system for commercial mining was analyzed. The key accomplishments, problems and future bends in research in the development of the mining system are also discussed. Finally, it points out that the technology gaps can be filled by the bine commercial mining is undertaken as a result of market conditions in its favor.

Development of Mining Technology and Equipment for Seafloor Massive Sulfide Deposits

Seafloor massive sulfide（SMS） deposits which consist of Au, Ag, Cu, and other metal elements, have been a target of commercial mining in recent decades. The demand for established and reliable commercial mining system for SMS deposits is increasing within the marine mining industry. The current status and progress of mining technology and equipment for SMS deposits are introduced. First, the mining technology and other recent developments of SMS deposits are comprehensively explained and analyzed. The seafloor production tools manufactured by Nautilus Minerals and similar mining tools from Japan for SMS deposits are compared and discussed in turn. Second, SMS deposit mining technology research being conducted in China is described, and a new SMS deposits mining tool is designed according to the environmental requirement. Finally, some new trends of mining technology of SMS deposits are summarized and analyzed. All of these conclusions and results have reference value and guiding significance for the research of SMS deposit mining in China.

深海多金属结核集矿装置水力输送流场分析与试验

对深海多金属结核集矿装置水力输送流场进行了理论计算,得到了多金属结核粒径与输送通道最小输送速度的关系;仿真分析了喷嘴射流速度分别为15、20、25 m/s时输送通道内水流流态分布,给出了流道下表面30 mm处的流速。在实验室进行了输送喷嘴不同射流速度的采集试验,实验结果与理论计算及仿真分析结果相符。

深海采矿提升硬管受力特性影响因素敏感性分析

管道提升式深海采矿系统已逐渐成为深海采矿的主流系统,其系统中提升硬管流固耦合力学特性的分析成为深海矿产开发的关键问题。以适用于6 000 m水深深海采矿系统的提升硬管为研究对象,建立包括采矿船、提升硬管、提升泵与中继站等的全系统耦合模型,对硬管运动响应进行时域分析,研究不规则波引起的船舶运动以及水动力作用、海流以及浪流耦合作用对于提升硬管力学性能的影响和各影响因素的敏感性分析。结果表明管系受轴向张力为主,采矿船在波浪影响下的大幅运动将增加张力变化范围,改变管系受力特性,是影响管系受力特性最关键的因素。

深海采矿柔性管力学性能及加工工艺研究综述

海洋蕴藏着储量丰富的矿产资源,深海矿产资源开发逐渐成为学术界和工程界的研究热点。管道提升式开采方案是目前公认的最具商业前景的海洋矿产开发方案。矿产输运管道作为连接海底中继舱和海上采矿平台的纽带,需要承受恶劣的风、浪、流环境载荷和复杂作业工况的工作载荷,其设计制造和力学性能分析一直备受关注。相比于刚性管道,柔性管道的弯曲刚度小、便于安装与回收、使用寿命较长。然而,柔性管道的结构复杂,各层之间相互影响,金属柔性管道由于自身结构的限制,在深海采矿行业中难以广泛应用,人们开始把目光放在非金属柔性管的设计与应用上。本文回顾了柔性管的发展历程,总结阐述了柔性管设计及加工制造中的力学性能分析方法和力学特性,并对柔性管设计制造的未来发展提供力所能及的展望。

旋转水力提升多金属结核运动特性数值模拟

采用CFD-DEM耦合方法对多金属结核提升进行模拟,研究了垂直管道中不同旋转流场旋流比对水力提升多金属结核输运特性的影响。结果表明,随着旋转流场旋流比增大,旋转强度显著增强,流体流速最大值增大,颗粒群轴向平均速度增大。旋转流场的旋转强度明显影响管道内颗粒的速度分布:速度大的颗粒逐步分布在管壁周围,速度较小的颗粒分布在管道中心处。旋转流场可降低颗粒群局部浓度,有利于降低因颗粒滞留效应引起局部浓度升高造成的输送管堵塞风险。

基于尾流振子模型的柔性悬挂立管涡激振动分析

为了分析深海采矿柔性立管涡激振动响应特性,提出了一种高效的针对特殊边界的处理方法.基于欧拉梁模型和尾流振子模型,结合有限差分方法,系统研究不同边界条件、中间仓质量和海流剪切参数对深海采矿立管涡激振动的影响规律.结果表明:悬挂立管底部会产生较大位移,与传统两端铰接立管相比,相同激励下悬挂立管会激发出更高阶的振动模态,从原本5阶模态升至6阶;随着中间仓质量增加,立管振动的主导模态会随之降低,在同一模态下,悬挂立管底部位移逐渐减小,从0.460降至0.405,当模态转换时,底部位移均方根会迅速增大,由0.405升至0.413;底部位移随着均匀流速的增加呈现出波动趋势,在一定流速范围内,位移随流速线性变化;随着剪切参数增大,在同一模态下,立管底部的位移逐渐减小,当模态转换时,底部位移会增加.

履齿结构对深海沉积物扰动分析

为探究集矿车在行进过程中履带运动对深海沉积物的扰动机理,并建立适用于机械结构与沉积物作用的仿真模型,结合水槽实验和模拟分析,设定对照试验,研究机械结构运动对沉积物的扰动作用和羽状流扩散现象。实验与仿真结果表明:偏置一字形履齿低扰动性能较好,扰动最大速度在1.5 m/s以下;扰动源的下陷深度和转速对水槽中的浊度变化有显著影响,浊度计最大和最小测量值为4 381.3 mg/L和3 073.3 mg/L,相差29.9%,峰值时间相差超过50%。搭建欧拉多相流模型,设定参数和边界条件,仿真与试验结果接近,可用于后续开展小范围内的机械扰动研究。

深海采矿系统模型水池试验方案

深海采矿系统单一模块研究无法准确反应其实际运行特性。搭建深海采矿系统模型水池试验平台,分析深海采矿系统运动力学特性,提出深海采矿系统模型全流程水池试验方案,为深海采矿系统全流程模拟提供技术支撑。

深海水下技术装备发展研究

深海水下技术装备是认知深海、开发深海资源以及保护海洋生态的关键,拓展深海新空间面临复杂多变的环境挑战,亟需高水平的深海水下技术装备作支撑。本文立足我国海洋强国建设的发展实际,分析了深海水下技术装备的体系构成和发展需求,从深海观测/探测与感知系统、水下施工作业装备、深海水下油气生产系统、深海矿产资源开发装备4个方面出发,梳理了国外深海水下技术装备的发展现状和趋势。在此基础上,总结了我国深海水下技术装备研制的发展现状,分析了发展面临的工程挑战,剖析了相关关键技术装备体系和关键物理–力学机制,概括了深海水下技术装备的典型装备代表和装备图谱,凝练了我国深海水下技术装备的共性关键技术,涵盖智能化与自动化技术、精密元器件加工制造技术、高精度定位导航、高速率通信技术、大系统力学计算与分析和跨尺度工程设计方法与技术等方面。为实现我国深海水下技术装备的高质量发展,研究建议:加强深海水下工程技术发展的顶层设计,推动构建共性关键技术协作体系;增强我国深海水下技术规范和标准的行业影响力,大力开拓国际市场;高质量推进兼容通用的平台建设;注重培养深海水下工程科技创新人才,为加速实现海洋科技产业高水平发展提供支撑。

扬矿过程中多金属结核破碎粉化特性试验研究

对扬矿过程中多金属结核破碎粉化特性进行了试验研究。结果表明,扬矿过程中结核破碎程度明显,体积浓度6.5%时,粒径大于50 mm的多金属结核质量占比从75.58%降至23.78%;体积浓度15%时,粒径大于50 mm的多金属结核质量占比从51.51%降至10.08%。试验中结核存在粉化现象,体积浓度6.5%时,粒径小于0.1 mm的多金属结核粉末质量占比为1.79%,粉末中值粒径为10.07μm;体积浓度15%时,粒径小于0.1 mm的多金属结核粉末质量占比为1.99%,粉末中值粒径为9.47μm。基于试验数据估算,采矿1 000万吨多金属结核,粉末排放会造成上万吨Fe、Mn和上百吨Co、Ni、Cu金属损失,其形成的羽流扩散沉降后的最大再沉积厚度大于3 mm,会对环境造成显著影响。

强迫振动下垂直管道固液两相流数值模拟研究

粗颗粒固液两相流的管道输运适用于深海采矿工程.扬矿管道在流致振动作用下的内部固液两相流的输运机理尚未被完全探究.因此,采用计算流体动力学(CFD)与离散元(DEM)耦合的方法,分析不同粒径、不同振动频率与振幅和不同浓度工况下在强迫振动管道中的粗颗粒动力学特性以及管内流场变化特性.其中,将管道的振动简化为一维径向振动,将实际工况中的柔性管道假定为刚体管道.研究表明,在管道振动过程中,大颗粒相比小颗粒的惯性更大,而流体也需要更大的速度产生更大的曳力推动大颗粒,导致更大的轴向流场速度以及更大的轴向颗粒速度.随着粒径增大,大颗粒对流场的扰动更大,导致流体与壁面间的作用力更大;并且大颗粒与壁面间的碰撞和摩擦作用力更大,因此壁面剪应力增大.同时,大颗粒与流体间摩擦损耗的能量也更大.因此管道需要更大的能量将其输运,导致振动管道内的压降增加.增大管道振动频率与振幅会导致颗粒在截面上的分布更加分散,同时对流场扰动更大,然而对轴向流场速度的影响相对较小.增大进料浓度使颗粒间、颗粒与流场间的作用更加频繁,导致颗粒分布发生变化,并导致更大的轴向流场速度和湍动能.

深海采矿船总强度有限元计算方法及结果分析

为了解深海采矿船在位工况时环境载荷作用下的全船结构响应状态,选取合理的装载工况和波浪特征载荷,基于三维势流理论,对波浪载荷响应进行数值分析,确定设计波载荷并进行总强度计算。结果表明,根据《深海采矿设施指南》,以及CCS、ABS、BV的其他相关规范,可以形成一套可供参考的深海采矿船总强度分析的方法及要求;深海采矿船结构设计应重点关注月池及其相连结构、货舱区纵向桁材向舱壁的过渡结构,以及货舱区角隅等结构区域。

深海采矿装备布放回收过程中脐带缆动力学响应特性研究

基于时域耦合分析法,建立了母船-深海采矿装备-脐带缆三维非线性水动力学模型,并对布放及回收过程中脐带缆的水动力响应特性进行了数值计算与分析。结果表明,4级海况时,深海采矿装备(水中重10 t)可以在速度0.8 m/s条件下安全布放和回收;在波浪和海流共同作用下,深海采矿装备在布放开始阶段和回收结束阶段都有强烈的振荡和摆幅,可安装防摇止荡装置来降低振荡和摆动。

深海金属采矿装备与技术发展现状及分析

金属矿产资源是保障国家经济发展与建设的重要物质基础。在陆地稀有金属供应初显疲态的形势下,世界各国纷纷将资源战略瞄向稀有金属蕴藏丰富的深海。开展深海采矿装备与技术的研发攻关,是实现深海矿产资源高效开采的关键。首先,系统论述深海采矿科学技术与装备发展历程,重点分析拖斗式、连续绳斗式、自动穿梭艇式、管道提升式技术特点,总结梳理国内外深海采矿车、深海扬矿装备、深海采矿船3类装备的发展现状;然后,以当前研究与发展动态为基础,围绕采矿、输运、支撑平台3个领域,梳理采集技术、牵引驱动技术、轨迹与规划技术、羽流演变评估技术4项采矿技术上取得的成效和进展,总结气力提升技术、水力提升技术、过流部件保障技术、力学行为分析技术4项输运技术的研究动态,探讨收放技术、升沉补偿技术2项支撑平台技术的研究方向及进展;最后,鉴于经济、环境、装备与技术3个维度目前的发展形势,提出深海采矿技术科学目标由装备可控转变为绿色采矿、安全采矿,为应对未来深海采矿装备与技术发展面临的环境与安全挑战,分析提出有待于聚焦研究的关键科学与技术问题,以此凝练出绿色行进采集技术、超深安全扬矿技术、全局协同保障技术、数字环境评估技术4项亟待突破的关键技术,以期为我国深海采矿装备体系研究与建设提供参考。

一种ROV型深海矿物采集装置的路径跟踪控制方法

本文针对一种新型遥控无人潜水器(Remote Operated Vehicle,ROV)拖曳采集装置(Mining Robot,MRT)的路径跟踪问题,提出一种路径跟踪控制方法。首先建立简化的ROV型深海采集装置的运动模型,随后提出一种基于线性模型预测控制算法(Linear Model Predictive Control,LMPC)和非线性模型预测控制器(Nonlinear Model Predictive Control,NMPC)的路径跟踪算法。与传统的模型预测控制器(Model Predictive Control,MPC)不同,本文提出的双层模型预测控制算法(Double Model Predictive Control,DMPC)由两部分组成:(1)由MRT的LMPC控制器计算得到MRT的速度控制律,用于快速收敛MRT的跟踪误差;(2)由ROV的NMPC控制器计算得到ROV的控制输入,用于响应MRT的速度控制律。在DMPC的设计中,有效考虑状态量和控制量约束,其中为了保证ROV控制输入的平顺性,引入ROV的控制量增量约束。最后,设计仿真实验用于验证MRT的路径跟踪效果,数值仿真结果证明了该算法的有效性。