Research On Structure Of Nature Gas-hydrate Drilling Coring Fidelity Device

Paper does research on structure of Nature Gas-hydrate drilling coring fidelity device by using the methods of theoretical analysis, experimental and numerical simulation study from the sampling length, thermal analysis, and sealing form.In the paper, the sampling tube penetrating the seabed is modeled as a sphere cavity expansion process. On the basis of the spherical cavity expansion theory,the height of the NGH sample is calculated under the influence of the "pile effect".We got the Math Expressions of the sample based on the the spherical cavity expansion theory and offer the ideas which can ameliorate the "pile effect". Thesis studies show that radiation heat transfer can not be ignored in the course of undersea nature hydrate sampling by experiments, and a mix of different heat transfer is reckoned, the result shows that the proposed structure can meet requirements of working condition. The numerical simulation with finite element simulation software ANSYS on O-ring is conducted to study the relationship between the material properties and pre-compression rate. It gets the maximum initial contact pressure and its distribution at different materials come in different O-ring compression ratio by simulation. And tHrough data processing,we have been fitted a mathematical expression to solve the maximum initial contact pressure of the O-ring under normal condition, which also improve the general theory of maximum contact pressure. It provides a theoretical support for selection and design of the O-ring seal.