Structural Optimization And Experimental Research Of Quick Connector For Deep-sea Mining Mixed Transportation Pipeline

The marine mixed transportation pipeline is a new method of submarine mineral mining,which improves the problem of low efficiency of traditional mining methods.Pipeline connectors are used for quick connections between risers in the entire seabed mining.Therefore,pipeline quick connectors have very important research value.Aiming at the problems of slow connection speed and small carrying capacity of traditional mixed transportation pipeline connectors,a connector for mixed transportation riser connection is designed and its supporting quick assembly and disassembly device to perform mechanics on the pipeline-connector system Analyze and perform parameterization and lightweight design of the connector body,mechanical test of the load-bearing capacity of the connector and vibration fatigue test of the connector.In view of the working environment and specific load-bearing conditions of the marine riser,the overall structure of a hybrid transmission riser connector with a locking block and a connecting flange as the core structure and a detailed mechanical-based design of all its parts are proposed.Conduct strength check on core parts.The overall plan of the assembly and disassembly device for this kind of mixed transportation pipeline quick connector is proposed,and all its parts are designed in detail,and the installation and disassembly process of the connector is given,that is,the use of the assembly and disassembly device.The dynamic analysis of the transmission rail part of the assembly disassembly device is carried out,and the transmission accuracy of the rail under the condition of different friction coefficients between the rail and the slider is obtained.According to the actual working conditions of the sea trial,perform mechanical analysis on the riser system,find the specific position of the maximum bending moment in the riser system,find the position of the connector closest to this position,and determine that the connector is subjected to the largest bending moment.The pipe-connector-pipe system corresponding to the connector is selected as the analysis unit,and numerical simulation of mechanics is performed on it,and the possible failure locations and maximum stresses of all parts are obtained.Parameterized design of the connector body,determined the objective function that can reflect the load-carrying capacity of the connector,analyzed the sensitivity of the design variables to the objective function and the parameter relevance,performed parameterized optimization of the connector,and compared the changes before and after the main objective function optimization to verify the reliability of the parameterized optimization design.After machining the parts of the designed connector,the pipes are welded at both ends and assembled,a test prototype of the hybrid pipeline connector is obtained.The test prototype is placed on the load frame of the composite load to perform the mechanical properties of the combined deformation of tension and bending.Test,and conduct sealing performance test at the same time.The test prototype was simplified into a variable cross-section beam model,and the discrete point method,singular function method and computer numerical simulation method were used to solve the lateral displacement of the simplified model.The corresponding results of the three analysis methods were compared to determine when the target bending moment loading was completed.Corresponds to the lateral displacement of the strain gauge position.Load the test prototype,read the special points on the test prototype pipe,the surface stress of the special points on the connector flange through the strain gauges,observe whether there is liquid leakage,whether the pressure gauge has pressure drop,and whether the test prototype has cracks.Finally verify the reliability of the connector design.The test prototype is simplified into a variable cross-section beam model to solve the natural frequency,and the mode function and mode curve of the test prototype are obtained.At the same time,the natural frequency of the test prototype model is solved by numerical simulation,and the two are compared.Verify that the theoretical solution of the simplified model is reliable.The harmonic response analysis of the test prototype shows that the vibration amplitude of the prototype is the largest at the natural frequency.According to the threaded connection and fatigue vibration test standards,the vibration test vibrates at the corresponding frequency,whether the prototype has cracks,and whether the fastening screws are tightened to determine the vibration resistance of the test prototype.