A proposal of the hybrid energy transfer pipe

Among the many modifications of superconducting power transmission lines, hybrid lines stand out for their originality. Their design implies the joint transmission of cold liquid fuel through the pipe and electricity through the high-temperature superconducting (HTS) cable cooled by this fuel directly or indirectly. Currently, the critical temperatures of HTS materials are low and that means that only liquid hydrogen can be the "cooling fuel". It is known that natural gas is a viable alternative to hydrogen as a chemical fuel for many reasons. Since its boiling temperature is too high, the use of liquefied natural gas (LNG) in hybrid lines is considered only in the future when suitable HTS materials will be discovered. Assuming that LNG cannot be used to cool HTS cable over the coming years, we propose to combine the LNG pipeline and the cable pipelines cold by liquid nitrogen in the common heat-insulating pipe. In addition to the considerable economic effect due to the common thermal insulation, the LNG cold will be utilized to cool the radiation shield that prevents the penetration of heat to the cable pipes.