This paper describes the basic structure and design and operation principle of the hydraulic drive and control system with two pumps and two circuits. The manipulator of the cone collecting robot designed is full driv...This paper describes the basic structure and design and operation principle of the hydraulic drive and control system with two pumps and two circuits. The manipulator of the cone collecting robot designed is full driven by hydraulic, which has five freedoms. The computer and electrohydraulic proportion velocity regulating valve were installed to realize open loop serve control for reducing cost and easy application.展开更多
The review covers the development and the state of the art in deep-sea mining rock mechanics,equipment and challenges.It begins by introducing the significance of deep-sea mining,the types and geographical distributio...The review covers the development and the state of the art in deep-sea mining rock mechanics,equipment and challenges.It begins by introducing the significance of deep-sea mining,the types and geographical distribution of deep-sea resources.Section 2 reviews the mechanical properties and fracture mechanism of seabed and related continental rocks,which contributes to the advancement of relevant technologies and theories.Deep-sea mining systems developed by coastal countries are presented in Section 3.Seabed mineral collection systems are critically assessed in Section 4.Subsea mining vehicle is reviewed by walking mechanism and controlling system in Section 5.In Section 6,the development of subsea lifting system is detailed by dividing it into hydraulic and pneumatic lifting modes,and some technical problems in the lifting system are described.An in-depth description of surface support systems is presented in Section 7,which includes the deep-sea mining ship,dynamic positioning system,heave compensation system,launch and retrieval system,mineral disposing system as well as the storage and transferring systems.Section 8 discusses the challenges in the deep-sea mining,in terms of natural occurrence conditions,international legal framework and cooperative mining,environmental protection and economic benefits,etc.Finally,a brief summary and some aspects of prospective research are presented in Section 9.展开更多
Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a su...Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.展开更多
We previously devised a new type of portable hydraulic turbine that uses the kinetic energy of an open-channel flow to improve output power by catching and accelerating the flow. The turbine contains an axial flow run...We previously devised a new type of portable hydraulic turbine that uses the kinetic energy of an open-channel flow to improve output power by catching and accelerating the flow. The turbine contains an axial flow runner with an appended collection device and a diffuser section that is not axisymmetric. The objective of this study is to determine how interference between the collection device and the runner influences performance characteristics of the turbine. We investigated the performance characteristics of the turbine and flow field for different numbers of blades during both unsteady and steady flow. During an unsteady flow, the maximum values of power coefficients for three and two blades increased by approximately 8.8% and 21.4%, respectively, compared to those during a steady flow. For the three-blade runner, the power coefficient showed small fluctuations, but for the two-blade runner, the power coefficient showed large fluctuations. These fluctuations in the power coefficient are attributed to fluctuations in the loading coefficient, which were generated by interference between the runner and the diffuser section of the collection device.展开更多
Hydraulic collecting and pipe transportation are regarded as an efficient way for exploiting submarine mineral resources such as the manganese nodules and ores.Coarse particles on the surface of the sea bed are sucked...Hydraulic collecting and pipe transportation are regarded as an efficient way for exploiting submarine mineral resources such as the manganese nodules and ores.Coarse particles on the surface of the sea bed are sucked by a pipe during the mining and crushing of the mineral.In this paper,the critical suction velocity for lifting the coarse particles is investigated through a series of laboratory experiments,and the solid-liquid two-phase flow characteristics are obtained.Based on the dimensional analysis,the geometric similarity is found between actual exploitation process and model test with the same kind of material.The controlling dimensionless parameters such as the hydraulic collecting number,the relative coarse particle diameter,the relative suction height,and the density ratio are deduced and discussed.The results show that the logarithm in base 10 of the hydraulic collecting number increases approximately linearly with the increase of the relative suction height,while decreases with the relative particle diameter.A fitting formula for predicting the critical suction velocity is presented according to the experimental results.展开更多
文摘This paper describes the basic structure and design and operation principle of the hydraulic drive and control system with two pumps and two circuits. The manipulator of the cone collecting robot designed is full driven by hydraulic, which has five freedoms. The computer and electrohydraulic proportion velocity regulating valve were installed to realize open loop serve control for reducing cost and easy application.
基金the support provided by the National Natural Science Foundation of China(Nos.51909075 and 52371275)the China Postdoctoral Science Foundation(No.2021M690879)the Chinese Fundamental Research Funds for the Central Universities(No.B230203007).
文摘The review covers the development and the state of the art in deep-sea mining rock mechanics,equipment and challenges.It begins by introducing the significance of deep-sea mining,the types and geographical distribution of deep-sea resources.Section 2 reviews the mechanical properties and fracture mechanism of seabed and related continental rocks,which contributes to the advancement of relevant technologies and theories.Deep-sea mining systems developed by coastal countries are presented in Section 3.Seabed mineral collection systems are critically assessed in Section 4.Subsea mining vehicle is reviewed by walking mechanism and controlling system in Section 5.In Section 6,the development of subsea lifting system is detailed by dividing it into hydraulic and pneumatic lifting modes,and some technical problems in the lifting system are described.An in-depth description of surface support systems is presented in Section 7,which includes the deep-sea mining ship,dynamic positioning system,heave compensation system,launch and retrieval system,mineral disposing system as well as the storage and transferring systems.Section 8 discusses the challenges in the deep-sea mining,in terms of natural occurrence conditions,international legal framework and cooperative mining,environmental protection and economic benefits,etc.Finally,a brief summary and some aspects of prospective research are presented in Section 9.
基金Supported by the "863" Foundation under Grant No.2002AA401000
文摘Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.
文摘We previously devised a new type of portable hydraulic turbine that uses the kinetic energy of an open-channel flow to improve output power by catching and accelerating the flow. The turbine contains an axial flow runner with an appended collection device and a diffuser section that is not axisymmetric. The objective of this study is to determine how interference between the collection device and the runner influences performance characteristics of the turbine. We investigated the performance characteristics of the turbine and flow field for different numbers of blades during both unsteady and steady flow. During an unsteady flow, the maximum values of power coefficients for three and two blades increased by approximately 8.8% and 21.4%, respectively, compared to those during a steady flow. For the three-blade runner, the power coefficient showed small fluctuations, but for the two-blade runner, the power coefficient showed large fluctuations. These fluctuations in the power coefficient are attributed to fluctuations in the loading coefficient, which were generated by interference between the runner and the diffuser section of the collection device.
基金The authors of this paper would like to thank the financial supports provided by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant XDA22000000).
文摘Hydraulic collecting and pipe transportation are regarded as an efficient way for exploiting submarine mineral resources such as the manganese nodules and ores.Coarse particles on the surface of the sea bed are sucked by a pipe during the mining and crushing of the mineral.In this paper,the critical suction velocity for lifting the coarse particles is investigated through a series of laboratory experiments,and the solid-liquid two-phase flow characteristics are obtained.Based on the dimensional analysis,the geometric similarity is found between actual exploitation process and model test with the same kind of material.The controlling dimensionless parameters such as the hydraulic collecting number,the relative coarse particle diameter,the relative suction height,and the density ratio are deduced and discussed.The results show that the logarithm in base 10 of the hydraulic collecting number increases approximately linearly with the increase of the relative suction height,while decreases with the relative particle diameter.A fitting formula for predicting the critical suction velocity is presented according to the experimental results.
