Research On Near The Bottom Of Deepsea Biological Larva Pressure-retained Sampler Of Multiple Nets Subsection/Layered

With the exhaustion of the resource in mainland ,human beings pay their attention to the vast ocean. With the development of technology, human beings speed up the pace of exploration of marine life, thus a variety of marine life sampler appeared. Aiming at mainly near the bottom of the deep-sea hydrothermal biological larvae, this article developed a set of biological larvae pressure-retained sampling system.Most of the marine life sampling system have two major issues.First of all it cannot maintain pressure,Secondly only can be in the stratified water column in the vertical drag sampling, they can not be near the bottom in the sub-collection sampling.In this paper, the design of the sampler is expected to solve these two issues.The thesis includes six chapters.In chapter 1, firstly we introduce the background of marine life sampler, then analyze the advantages and disadvantages of present marine life sampler, and its developing trend. Finally, we put forward the purpose, significance and main content of this project.In chapter 2, we first introduce the overall structure of the biological larvae pressure-retained sampler. Then expound on principle on the three studies.In chapter 3, we have been mainly studied on multiple networks subsection / layered automatically switch machine of the biological larvae pressure-retained sampler.Then put forward three design options:Spring machine,Lever machine and Hydraulic drive machine.Comparing with the three options,finally we adopt the hydraulic drive machine to achieve the automatic switching network functions.In chapter 4, we first introduce the overall structure of the pressure-retained system of marine life sampler.then study the material and pressure design guidelines of the pressure-retained cylinder.In the design of the pressure-retained cylinder,we adopt the safest design criteria to make the design more secure.In order to verify the reliability of the design,we have done the FEA to the cylinder.Then we introduce the design of ball valve, With the FEA software,such as ANSYS,we have done the stress analysis on a ball valve.In the end, we introduce the seal design of the pressure-retained cylinder.In chapter 5, we mainly do a further study on the design of pressure compensation containers.Through the pressure loss calculation of the pressure-retained cylinder, we prove the necessity of the design of pressure compensation containers.Through studying on the four kinds of pressure compensation containers,we select the precharge pressure accumulator as the pressure compensation containers of sampler.Then researching on the maintaining pressure process of accumulator deeply,mathematic model of pressure compensation process is established, and calculation formula of sample's final pressure is deduced.Through MATLAB simulation, we get the relationship between the volume and precharge pressure of accumulator and sample's final pressure.In the end,we use a volume of 0.63 liters and the precharge pressure of 30 MPa of accumulator.The last chapter, we look back to the whole thesis and put forward the fruits of the study. At last, the further study direction is brought out.