Research On Thrusters For 11000m Deep Sea High-pressure High-viscosity High-attenuation Environment

Mariana trench,whose depth is 11000 meters,is a junction between the international submarine polymetallic nodule mining area,cobalt-rich crust mining area and China's exclusive economic zone,and the detection and protection of the environment in the sea area is the basic guarantee for the long-term existence of the international seabed mine.11000-meter-depth manned submersible is the core carrier to undertake the mission of environmental protection.Thrusters are the most core components of the 11000-meter-depth manned submersible.In order to avoid the occurrence of the problem of the 11000-meter-depth manned submersible,such as overweight affecting the hoisting,low reliability resulting in accident,too much noise affecting the communication with the ship,thrusters should be light weight,high reliabile and low noise.In order to develop the 11000-meter-depth thruster for the requirement of the 11000-meter-depth manned submersible,this paper will deeply carry out research on the lightweight and integration of the structure,the reliability of the extended shaft dynamic seal,the high pressure resistance and low noise of the embedded driver of 11000-meter-depth thruster for the requirement of the 11000-meter-depth manned submersible and the high pressure,high viscosity and high attenuation working environment.This paper is divided into six chapters:The first chapter introduces the background of this paper,and the research status of the 11000-meter-depth manned submersible and deep-sea thrusters,and put forward the main content and significance of this paper based on the analysis of the propulsion system requirement for 11000-meter-depth manned submersible and the advantages and disadvantages of various types of thrusters.The second chapter put forward the design scheme of high-pressure and light-weight of 11000-meter-depth thruster based on the principle of deep sea pressure compensation for the high-pressure work environment and the light-weight requirement,and completes the optimization design of the whole structure and the design,calculation and simulation analysis of the detail structure according to the design scheme.The third chapter research on the extended shaft seal reliability of the high viscosity oil-filled thruster.Firstly,research on the high-viscosity fluid at the extended shaft dynamic seal by using the theory and fluid simulation software to analysis the influence of the structure of the extended shaft dynamic seal and the change of oil viscosity on the fluid pressure distribution,and find the reason of the unreliability of the dynamic seal combining with the the analysis of the specific pressure of the mechanical seal face.Then,put forward a kind of low swirl mechanical seal structure and verify its the low swirl characteristics by using fluent.The fourth chapter put forward the design scheme of high-pressure and low-noise of the embedded drivers based on the high-pressure work environment and the low-noise requirement,and completes the selection of anti-high pressure components,the design of the anti-high pressure hardware circuit and software control system,which ensure low noise and high reliability of the 11000-meter-depth thruster.The fifth chapter is aimed at the experiment research of the 11000-meter-depth thruster.It designs the corresponding experiments to verify the control and high pressure resistance of the embedded driver,the rationality and reliability of the optimization design scheme of the thruster and the reliability of the low swirl mechanical seal structure.The sixth chapter summarizes the main research work,points out the innovation of this paper and put forward the direction of improvement based on the shortcoming of this paper.