Research On Composite High Temperature Super-conducting Energy Pipeline

Composite superconducting energy pipelines with integrated clean energy cooling are an efficient and promising energy transmission alternative to meet the growing global energy demand.In this paper,based on the research status and development trend of high-temperature superconducting(HTS)energy pipelines at home and abroad,in order to realize energy interaction,improve energy transmission characteristics and improve energy transmission efficiency,a composite HTS energy pipeline integrated with liquid hydrogen,liquefied natural gas and superconducting power transmission is proposed.And the structural design,characteristic analysis,structural optimization and energy efficiency analysis are deeply studied.The constitutive relationship,anisotropy and numerical model of high-temperature superconductors are analyzed.The critical current expression formula,optimal intermediate parameters and modeling methods of HTS tapes are obtained,which can provide a reference for the research of composite HTS energy pipeline.The structure and design principles of the composite HTS energy pipeline are proposed,including the parameter design of skeleton,superconducting conductive layer,insulating layer,shielding layer and tape joints.The optimal parameters of the inner diameter of the pipeline are solved by the methods of the maximum allowable temperature difference and the maximum allowable pressure drop,and the optimal arrangement and parameters of the superconducting layer and other layers are solved by simulation.And the structural advantages of the composite HTS energy pipeline are expounded.Based on the above structural design,a two-dimensional axisymmetric electromagnetic thermal coupling model of composite HTS energy pipeline is established via the magnetic field formula interface,heat transfer model and multi physical field coupling interface.The characteristics of magnetic flux density distribution,temperature distribution and critical current density distribution of composite HTS energy pipeline are comprehensively simulated and analyzed.Compared with the conventional superconducting energy pipeline,the characteristic advantages of the proposed composite HTS energy pipeline are analyzed.Aiming at the problem of uneven current distribution in the multi-layer structure of composite HTS energy pipelines,two hybrid optimization algorithms for HTS current sharing based on particle swarm optimization(PSO)and artificial bee colony(ABC)are proposed.The optimized current distributions between HTS layers are analyzed,and the structural optimization parameters are solved.Build a 3D model according to the solved structural parameters and analyze its electromagnetic properties.Compared with the optimization results of PSO,it is proved that the two current sharing optimization schemes can better improve the characteristic distribution of HTS layer.The effectiveness of the proposed algorithms is further analyzed and verified via changing the number of layers,angular frequency and current of HTS conductor layers.A superconducting energy internet system based on proposed composite HTS energy pipeline is designed.The influence mechanism of current,structure and harmonic factors on transmission loss is discussed.The system energy efficiency is calculated,including transmission energy efficiency,thermal energy efficiency and entire energy efficiency.And compared with the conventional superconducting energy pipeline system,it indicates the high efficiency of the composite HTS energy pipeline system.