Optimization Of The Sealing Structure And Analysis Of Thermal-structure Coupling Of Self-driven Subsea Pipeline Connector

Submarine pipeline is an important way to transport crude oil by sea,once leakage occurs,it will cause great harm to the Marine environment and great impact on economy and society.Pipe connectors can be used for quick connection during pipeline repair.Therefore,the research of connectors is of great significance.Aiming at the problems of difficult connection and poor sealing reliability of subsea pipeline connectors,in this paper,Taking Self-driven subsea pipeline connector as research object,the mechanical analysis of the sealing ring,the optimization of the sealing structure,the analysis of the temperature field and coupling stress,and the prototype test of the connector are carried out.Based on the comprehensive analysis of the complex marine environment and the performance index of the pipeline connector,the overall structure and each component of the Self-driven subsea pipeline connector are designed,and the installation process of the connector is given.By analyzing the sealing process of the connector,analyzing and calculating the sealing behavior of the sealing ring at different working stages,the mathematical expression of the contact stress and driving force of the Self-driven subsea pipeline connector are obtained,and the maximum driving force for the connector to achieve reliable sealing is obtained for the connector to achieve stable sealing.According to the sealing mechanism scheme of the connector and the working conditions of the connector,the material of the sealing ring is determined,and a uniaxial tensile test of the rubber is performed.Then,through fitting,the constitutive model parameters of the superelastic material used in this paper are determined.Taking the sealing mechanism of the connector as the research object,the contact stress distribution characteristics of the conventional sealing mechanism and the anti-outburst sealing mechanism are analyzed through finite element simulation,and the sealing scheme with good sealing effect is determined.The target variables that can reflect the sealing performance of Self-driven subsea pipeline connector are determined,the contribution rate of design variables to each target variable is analyzed,and the key design variables are determined.In order to improve the sealing performance,the size of the sealing mechanism of the connector is optimized,and the sealing performance before and after optimization under the same loading conditions is compared to verify the rationality of the optimized design.Aiming at the problems of thermal convection and radiation related to the Self-driven subsea pipeline connector and the surrounding environment,the heat transfer method of the connector is simplified by an equivalent method.Based on the static analysis of the Self-driven subsea pipeline connector,the finite element model of the connector under temperature load is established by using the complete thermal coupling method,and the transient and steady-state analysis are performed.The temperature field distribution characteristics of the seal mechanism at steady state and the temperature change law with time under transient conditions are obtained.The stress and sealing performance of the seal ring of the connector under different operating conditions are studied.In order to verify the correctness of theoretical calculation and numerical simulation,a prototype of an 8-inch Self-driven subsea pipeline connector with a size of 1: 1 is fabricated.Through the load test of the connector,the correctness of driving force calculation is verified.Through the comparison of the sealing performance test,it is verified that the anti-outburst design effectively improves the sealing performance of the connector,and it is verified that the optimized sealing structure has better performance.Through the temperature and pressure test,it is verified that the Self-driven subsea pipeline connector has good sealing performance at high temperature.