Design And Experimental Research Of Rapid Connection Method Of Deep-sea Mineral Mixed Transportation Pipeline

In the deep-sea mixed transportation mining system,the mixed transportation pipeline plays a vital role in the process of mineral transportation.In order to ensure the rapidity and reliability of pipeline connection,a fast connection method is proposed,including a fast connection equipment composed of connector and connection device.Through model analysis,it is determined that the key research object of rapid connection equipment is clamp connector.Based on the vibration theory and finite element simulation,the static analysis and vibration analysis of the connector are carried out,and its fatigue life is predicted.Based on fuzzy mathematics and fault tree analysis,the reliability of fast connecting equipment is analyzed.Finally,the laboratory and sea trial tests of the rapid connection equipment are carried out.The results show that the rapid connection equipment can realize the function of rapid disassembly and assembly of pipeline under the target working condition,and can maintain stable operation during two 24h cycle tests.In view of the working condition that the mixed transmission pipeline system needs to ensure the bearing capacity and assembly and disassembly speed of the connection system at the same time,the overall scheme design of the mixed transmission pipeline quick connector matched with the split clamp and the inclined flange is carried out.Based on the detailed design of the bearing conditions of the connector working environment ocean current analysis,the key parameters of the core parts are determined.The overall scheme design of the connecting device matched with the quick connector is carried out,the disassembly process and operation procedures are described,and the detailed design of key components is completed based on the riser offset conditions and the working conditions of the connector.The key components of the connector and connecting device are checked and simulated by finite element method,and the optimization scheme is proposed based on the finite element simulation results.According to the ocean wind and wave conditions predicted by hydrology,the pipeline system is simplified into a cylindrical flow model,and its vortex induced effect is analyzed.The Bernoulli Euler beam model and Timoshenko beam model are introduced to analyze the modal of the pipeline system and quick connector,and the first six natural frequencies of the riser are obtained.The finite element software is used to analyze the amplitude,stress and other parameters under the modal frequency,and the fatigue life of the pipeline system is predicted based on the dangerous frequency.It is verified that the life of the connector under the working conditions meets the requirements of the sea test.The reliability and fuzzy mathematics theory are introduced to analyze the reliability of fast connecting equipment,aiming at the problems that the external load conditions are not fully considered in the traditional design process and the internal parameters change with time.This paper expounds the theory and method of reliability research,constructs the stress strength interference model in line with the system,and defines the system reliability analysis process.The stress of key parts of the connector is analyzed by finite element method,and the node stress is derived and sorted.The reliability is solved according to the stress strength interference model and Monte Carlo method to verify the reliability of a single key part.The system fuzzy fault tree model is established,the top event failure probability is calculated,the reliability is allocated according to the system reliability of fault tree analysis,and the optimization method to improve the reliability of fast connecting equipment is proposed.The connector laboratory test samples and corresponding mechanical test conditions are designed according to the actual conditions.The tensile and bending test is carried out after the test samples are processed and assembled.Under the maximum tensile and bending load,the test samples do not have internal pressure reduction and cracks.According to the national standard and local modal analysis results,the vibration test of the connector test sample is carried out to verify the change of vibration frequency of the test sample,the maintenance of connector bolt torque and the integrity of the sample.Process and assemble the connecting device,complete the function test of the connecting device according to the sea trial offset conditions,and verify the synchronization rate,loading and unloading function and loading and unloading time of hydraulic cylinders on both sides.The sea test is carried out in Xisha sea area of the South China Sea.The rapid connection equipment can realize the function of rapid disassembly and assembly in the sea test process,and can maintain stable operation in two 24h cycle tests,which verifies the correctness and reliability of the theoretical analysis results.