Design And Characteristic Analysis Of Pipeline Lift Frame For Deep-Water Subsea Pipeline

The pipeline lift frame of deep-water subsea pipe is the key equipment for emergency maintenance of deep-water subsea pipe.The pipeline lift frame cooperates with the underwater robot to lift the subsea pipe off the seabed,which can provide working space for subsequent subsea pipe maintenance.At present,China’s research on deep-water subsea pipeline lift device is not mature,and the technical performance of the existing equipment is low.Therefore,in order to meet the demand of emergency repair equipment of deep-water subsea pipelines,a new deep-water subsea pipeline lift frame for emergency maintenance of 1500 m subsea and maximum pipe diameter of 20 in pipelines is designed in this paper.The main research work of the paper is the overall structure design and hydraulic control system design of the deep-water sea pipeline lift frame,specific research works are as follows.(1)The overall design plan of the deep-water pipeline lift frame is proposed.According to the technical requirements and application conditions of deep-water pipeline lift frame,combined with the main maintenance process of deep-water subsea pipelines at the present stage,the overall design of deep-water subsea pipe lifting frame applicable to the emergency maintenance process of deep-water submarine pipelines is proposed.And the design of the clamping mechanism,traverse mechanism,leg lifting mechanism and stabilization and anti-sinking mechanism of the pipe lifting frame is completed.(2)The structural model of the deep-water pipeline lift frame is constructed.According to the operation requirements of deep-water marine pipe,the material and characteristic parameters of the main structure of deep-water marine pipeline lift frame are determined.Based on the static analysis,each part of the frame is modeled,and the hydraulic cylinder parameters of each mechanism are analyzed and calculated.(3)The optimization method of clamp performance based on orthogonal optimization is proposed.The main force components of the deep-water pipeline lift frame are analyzed.Through numerical simulation based on finite element software,the force analysis and strength check of the crossbeam,transverse skid,clamp base and clamps of the pipeline lifting frame are carried out and the maximum working load of the pipeline lift frame under stable working condition is determined.By analyzing the main factors affecting the performance of the pipe lifting clamp,the orthogonal experimental design is introduced,the multi-objective optimization strategy of the pipe lift clamp in deep-water is proposed,and the clamp performance optimization method based on orthogonal optimization is established.The deformation and stress of the clamp of the deep-water pipeline lift frame are used as the target to optimize and update its structural parameters and other influencing factors,which verified the effectiveness of the proposed method.(4)A hydraulic control system based on synchronization analysis is established.Focusing on the operation requirements of deep-water subsea pipeline lift frame,the main work flow of deep-water subsea pipeline lift frame is explored,and the hydraulic control system under different working modes is designed.In view of the poor synchronization of the conventional hydraulic control system of the deep-water pipeline lift frame,the synchronization circuit of the lifting mechanism of the hydraulic control system is designed and the model of the control system of the deep-water pipeline lift frame is constructed.Simulation experiments are used to analyse the factors influencing the performance of the hydraulic control system,optimize the synchronisation of the hydraulic control system and improve the performance of the designed hydraulic control system for deep-water marine pipeline lift frames.