Analysis Of The Thermal Coupling Effect For Deep-sea Tunnel Under High Temperature And Pressure

Nowadays,research on effect of temperature on pipes under non-uniform temperature field based on deep-sea environment is insufficient.In this paper,the results based on non-uniform temperature field are described.Calculation is carried out by FLUENT calculation.A research on the temperature effect on both single and double layer pipe,with respect to long pipe and short pipe,is performed.Furthermore,special attention are paid on the phenomenon and influencing factors of longitudinal movement of double layer pipe.Meanwhile,an experiment on the coupling of thermal structure of double layer pipe is conducted to verify the numerical solution.The mechanism of pipe buckling is discussed.To start with,the software ABAQUS is used.Based on the analysis of temperature effect under non-uniform temperature field on single layer pipe,the ITT element is imported to establish a double layer pipe model.Then the simulation result is compared with theoretical solution in Temperature-Stress method,thus the temperature induced stress along longitudinal direction for both short and long pipes are analyzed.A non-uniform temperature field is introduced to the abovementioned model to obtain the temperature effect of both short and long double layer pipe.Secondly,the non-linear cyclic temperature effect is implemented in the abovementioned double layer model to illustrate the longitudinal movement in short straight double layer pipe.Influences of pipe-soil friction and internal pressure distribution are considered to provide theoretical solution for reducing longitudinal movement of double layer pipe.Lastly,with an oil thermal device,an experiment on the coupling of heat structures is conducted on the double layer pipe structure.This will help verify the numerical solution,explore the mechanism of deep-sea pipe buckling as well as obtain the buckling modes and temperature changes before and after the pipe buckling.