Research On Structure Design And Sealing Technology Of Full-ocean-depth Pressure-retaining Water Sampler

It is very important to collect seawater samples and obtain their composition information for marine exploration and microbial research.For this reason,various types of deep-sea samplers have been developed at home and abroad.With the advancement of deep-sea equipment technology,full-ocean-depth water samplers with pressure-retaining function have become important sampling tools,and their structure and performance still have some room for improvement.Therefore,in this paper,the structure of the full-ocean-depth water sampler is designed,and its key sealing and pressure-retaining technology is studied.By investigating the related technologies of deep-sea samplers at home and abroad,combining with the key design requirements of the full-ocean-depth and pressure-retaining,the overall structure scheme of water sampler is proposed.A balanced spool structure for ultra-high pressure valve body is designed,and the driving device of sampling valve based on explosive bolt is innovatively designed.Aiming at the problem of seawater sample pollution that may be caused by the detonation of gunpowder in the explosion bolt,an underwater anti-pollution isolation device is designed based on the driving device.According to the working principle and triggering condition of explosive bolt,the electromagnetic induction underwater wireless power supply scheme is proposed by comparing various underwater power supply modes,and the underwater trigger device is tested preliminarily.The pressure compensation effect of the sampling cylinder structure of the accumulator in the process of sample recovery is analyzed.The structure of a sampling cylinder which can be used to prevent the contamination of the sample by the snorkel and sample valve dead volume is introduced and its feasibility is discussed.Based on the finite element method,the key sealing technology of full-ocean-depth pressure-retaining water samplers is studied.The conical sealing performance of the spool-seat is analyzed.The results show that the sealing property of the sampling valve is good when the force load of the non-uniform cone seal is 600N in the simulation environment.Referring to the size of the sealing force load of the sampling valve,the structure of the valve core is analyzed based on the finite element method to ensure that its strength meet the working requirements,and the underwater explosive bolt code-named XX-60 is selected to design and check the key parts of the driving device.The analytical method is used to study the pressure-retaining performance of sampling cylinder.The pressure-retaining rates of sampling cylinder without accumulator and sampling cylinder with accumulator are calculated respectively,and the influencing factors of the pressure-retaining performance of the sampling cylinder are analyzed.The results show that the sampling cylinder with accumulator has better pressure-retaining performance.The larger the gas pre-charging pressure of the accumulator,the higher the pressure-retaining rate of the sample.