Effects of heave motion on the dynamic performance of vertical transport system for deep sea mining

2020 ◽  
Vol 101 ◽  
pp. 102188 ◽  
Author(s):  
Qi Wu ◽  
Jianmin Yang ◽  
Haining Lu ◽  
Wenyue Lu ◽  
Lei Liu
Keyword(s):  
Transport System ◽  
Deep Sea ◽  
Dynamic Performance ◽  
Vertical Transport ◽  
Heave Motion

Assessment of Different Technologies for Vertical Hydraulic Transport in Deep Sea Mining Applications

2012 ◽  
Author(s):  
Stanislav Verichev ◽  
Valery Drobadenko ◽  
Nikolay Malukhin ◽  
Alexandr Vilmis ◽  
Pieter Lucieer ◽  
...  
Keyword(s):  
Transport System ◽  
Deep Sea ◽  
Transportation Systems ◽  
Vertical Transport ◽  
Hydraulic Transport ◽  
Mining System ◽  
Positive Displacement ◽  
Pros And Cons ◽  
The Right ◽  
Offshore Mining

Successful mining of deep sea deposits strongly depends on the proper choice of the right equipment. The most probable concept for a deep sea mining system would consist of the three major sub-components: Seafloor Mining Tool, Vertical Transport System and Mining Support Vessel. In this paper, emphasis is placed on the Vertical Transport System. We analyse the pros and cons of the different concepts such as hydraulic transport using centrifugal or positive-displacement slurry pumps, conventional and unconventional airlift systems, vertical offshore mining systems and vortex slurry transportation systems. All these systems are considered for their applicability at different water depths (from the relatively shallow to the relatively deep) for the different types of materials (from the relatively fine to the relatively coarse) and various production rates in terms of the efficiency, reliability and state of the art of technology.

Heave Induced Internal Flow Fluctuations in Vertical Transport Systems for Deep Ocean Mining

2014 ◽  
Author(s):  
Stephan D. A. Hannot ◽  
Jort M. van Wijk
Keyword(s):  
Transport System ◽  
Internal Flow ◽  
Deep Ocean ◽  
Vertical Transport ◽  
Transport Systems ◽  
Ship Motions ◽  
Centrifugal Pumps ◽  
Mining System ◽  
Pump System ◽  
Ocean Mining

Deep ocean mining systems will have to operate often in harsh weather conditions with heavy sea states. A typical mining system consists of a Mining Support Vessel (MSV) with a Vertical Transport System (VTS) attached to it. The transport system is a pump pipeline system using centrifugal pumps. The heave motions of the ship are transferred to the pump system due to the riser-ship coupling. Ship motions thus will have a significant influence on the internal flow in the VTS. In this paper, the influence of heave motions on the internal flow in the VTS for a typical mining system for Seafloor Massive Sulfide (SMS) deposits in Papua New Guinea is analyzed. Data on the wave climate in the PNG region is used to compute the ship motions of a coupled MSV-VTS. The ship motions then are translated into forces acting on the internal flow in order to compute fluctuations in the internal flow. In this way, the workability of the mining system with respect to the system’s production can be assessed. Based on a detailed analysis of the internal flow in relation to ship motions, the relevance of a coupled analysis for the design of VTS is made clear. This paper provides a method for performing such analyses.

scholarly journals Numerical and Experimental Research on the Effect of Platform Heave Motion on Vortex-Induced Vibration of Deep Sea Top-Tensioned Riser

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jie Zhang ◽  
Ying Zeng ◽  
Yougang Tang ◽  
Wenyun Guo ◽  
Zhenkui Wang
Keyword(s):  
Parametric Excitation ◽  
Deep Sea ◽  
Frequency Component ◽  
Vortex Induced Vibration ◽  
Wake Oscillator ◽  
Validation Experiment ◽  
Simulation And Experiment ◽  
Prediction And Control ◽  
Heave Motion ◽  
And Control

The prediction and control of vortex-induced vibration (VIV) is one of the key problems for riser design. The effect of platform heave motion on VIV of deep sea top-tensioned riser (TTR) is presented by means of numerical simulation and experiment in this research. First, the heave motion was modeled as a parametric excitation, and the governing equation of VIV of riser considering the parametric excitation was established. Then, the dynamic response of TTR was calculated numerically by the finite difference method based on the Van der Pol wake-oscillator model. Finally, a validation experiment was carried out at the towing tank of Tianjin university. The results show that the VIV response at the bottom of riser is significantly increased due to the platform heave motion, especially in the situation of low current velocity. The larger amplitude and the higher frequency of the platform heave motion with the greater influence are generated on VIV of TTR. In particular, the value of 0.5 times, 1 time, or other multiples of the platform heave frequency will be included in the vibration frequency component of TTR when the platform heave amplitude is large and the frequency is high.

An Integral Design Approach for Deep Sea Mining Systems Using Dredging Technology

2010 ◽  
Author(s):  
P. M. Vercruijsse ◽  
R. Lotman
Keyword(s):  
Transport System ◽  
Deep Sea ◽  
Mining Operation ◽  
Integral Solution ◽  
Mechanical Interaction ◽  
Pumping Power ◽  
Mining System ◽  
Mining Tool ◽  
Transport Flow ◽  
Slurry Transport

Experience in the area of wet mining and the dredging industry learns that the excavation system cannot be seen separate from the slurry transportation system. These two key systems in a deep sea mining operation interrelate to such extend that they must be developed towards an integral solution. The nominal production, peak production and variability of these figures must match for all sub-systems in the overall mining system to optimize for mining efficiency; we call this the ‘game of capacities’. Also the configuration of the excavation and transport system has great consequences. For instance an important question is whether to place the first pump and its drive of the slurry transport system on the seafloor mining tool or in the riser system. The choices made impact amongst others on; the mining tool’s reach (and thus efficiency), the seafloor mining tool’s propulsion system and its geo-mechanical interaction, the slurry transport flow and pumping power requirements. This paper will discuss the several dependencies of the (producing) subsystems and important choices for configuration and their consequences regarding technology, capex, opex, reliability and maintainability.

Hydraulic Sytem for Wave Compensation of Deep-Water Exploration Ship

2012 ◽  
Vol 192 ◽  
pp. 201-206
Author(s):  
Zhi Xin Chen ◽  
Shuai Liu
Keyword(s):  
Deep Water ◽  
Structural Parameters ◽  
Dynamic Performance ◽  
Wire Rope ◽  
Transmission System ◽  
Compensation System ◽  
Work Condition ◽  
Extraction Equipment ◽  
The Stability ◽  
Heave Motion

In order to reduce the influence of the bench extraction equipment from the working deep-water exploration ship when it has swing or heave movement by wind and waves, according to the work condition and the structural parameters of 3000m deep-water exploration ship, Pump-controlled type and valve-controlled type hydraulic transmission system for waves compensation of deep-water exploration ship bench extraction equipment was researched through analysing and calculating. Wire rope which drags the bench is maintained appropriate tensioning status using this wave compensation system, when bench downs to the bottom of the sea. This system can bind and release wire rope to compensate for heave motion automatically, in order to keep the stability and security of the deep-water exploration ship before bench loading the bottom. Dynamic performance of wave compensation system is improved through controlling supplementation pressure and the accumulator parameters precisely.

scholarly journals Prediction of Vortex-Induced Vibration Response of Deep Sea Top-Tensioned Riser in Sheared Flow Considering Parametric Excitations

2020 ◽  
Vol 27 (2) ◽  
pp. 48-57
Author(s):  
Guanghai Gao ◽  
Yunjing Cui ◽  
Xingqi Qiu
Keyword(s):  
Prediction Model ◽  
Deep Sea ◽  
Nonlinear Partial Differential Equations ◽  
Solution Process ◽  
Cross Flow ◽  
Vortex Induced Vibration ◽  
Sheared Flow ◽  
Wake Oscillator ◽  
Real Size ◽  
Heave Motion

AbstractIt is widely accepted that vortex-induced vibration (VIV) is a major concern in the design of deep sea top-tensioned risers, especially when the riser is subjected to axial parametric excitations. An improved time domain prediction model was proposed in this paper. The prediction model was based on classical van der Pol wake oscillator models, and the impacts of the riser in-line vibration and vessel heave motion were considered. The finite element, Newmark-β and Newton‒Raphson methods were adopted to solve the coupled nonlinear partial differential equations. The entire numerical solution process was realised by a self-developed program based on MATLAB. Comparisons between the numerical calculation and the published experimental test were conducted in this paper. The in-line and cross-flow VIV responses of a real size top-tensioned riser in linear sheared flow were analysed. The effects of the vessel heave amplitude and frequency on the riser VIV were also studied. The results show that the vibration displacements of the riser are larger than the case without vessel heave motion. The vibration modes and frequencies of the riser are also changed due to the vessel heave motion

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