Key Technologies Study On Deepsea Microplankton Concentrated And Gas-tight Sampling

Deepsea microplankton is a kind of deepsea resource recognized by human recently, which has important significance on the origin of life, discovery of new gene, development of new medicine and environment protection. The chief requirement of studying deepsea microplankton is to get plenty of samples. Limited by the volume of sampling vessel, currently sampler can only get fewer samples with single sampling and can not maintain the original pressure. In order to overcome the disadvantage of currently sampler, a new sampling technique with function of concentrated and gas-tight is proposed in this thesis.Based on the design of deepsea microplankton concentrated and gas-tight sampler, the following sampling techniques are lucubrated: pollution-free sampling technique, pressure-jump-free sampling technique and in-situ concentrated sampling technique; deepsea highprecision gas-tight sampling technique; sealing technique of superpressure seawater hydraulic system; reliability design technique of deepsea high pressure cabin. The major content of this thesis is as follows:Pollution-free and pressure-jump-free sampling technique is proposed to avoid polluting of the sampler before sampling and to avoid pressure jumping when seawater pushs into the sampling vessel, which is realized with a seawater high pressure check valve mounted on the entrance of the sampling vessel and a seawater high pressure check solenoid valve mounted on the outlet of the sampling vessel.In-situ concentrated sampling technique is proposed to realize concentrated sampling, which uses deepsea pump to extract seawater flow through filter member. In-situ concentrated sampling technique can increase the number of microplankton with single sampling markedly. It also helps to avoid sample loss and pressure decrease in laboratory filtering.Optimum design study of spring is finished to improve the dynamic performance of seawater high pressure check valve. A kind of solenoid check valve which can work in seawater with pressure of 60 MPa is designed to achieve automatic control sampling.Highprecision gas-tight design theory based on precharged accumulator is proposed, mathematic model of pressure compensation process is established, and calculation formula of sample's final pressure is deduced. Simulation study and experiment validation on the relationship of accumulator's parameter and pressure compensation results are finished.