Electrothermal Coupling Simulation of Termination Insulation of Superconducting Energy Pipeline

Superconducting DC energy pipeline realizes the mixed transportation of electric energy and liquid natural gas, which is a high efficiency and low energy consumption method of redistribution of energy. Superconducting DC electric termination is one of the cores equipment of superconducting DC energy pipelines which bears various extreme conditions such as electric field, large temperature gradient, mechanical stress, etc. Under the influences of multiphysics, the electrical and thermal properties of the terminal materials will change to varying degrees, and these changes will cause distortion of the physical field in turn. Therefore, in the design of the terminal structure, multiple physical interactions and mutual cooperation methods need to be considered. Under the two-way coupling of multi-physics and terminal material parameters, the physical simulation model of superconducting energy pipeline is established, and the electric field distortion in this model are analyzed.In this article, the physical model of superconducting energy pipeline terminal is established by COMSOL. And we find that the change rule of the material conductivity with temperature counts a great deal in the distribution of the electric field thermal field in the terminal. At the same time, the cooling power of liquid nitrogen influences the temperature distribution, thus affect the electric field indirectly to a certain extent. Therefore, in the optimization design of the terminal, selection of insulation materials, how to control the heat generation should take into consideration. This study provides theoretical support for the insulation optimization design of superconducting energy pipeline terminals.