The experiments of 200-meter superconducting DC power cable in Chubu university and the estimation for longer cable cooling

Abstract

After the 200-meter superconducting DC power cable experimental facility had been completed in spring of 2010, three experiments have been done until March, 2011. We adapt the straight pipe for the inner cryogenic pipe to reduce the heat leak and the pressure drop of liquid nitrogen circulation because the surface area is minimized for the straight pipe, and the terminal cryostats of the cable ends are movable to absorb the shrinkage of the cable in the cooling-down phase and the expansion in warming-up phase to reduce the tensile strain of the high temperature superconductor tape. We also continue the Peltier current lead experiment to reduce the heat leak at the terminal. We performed several kinds of the experiments to obtain the basic data for a long cable system. We changed and improved the experimental devices during the experiments. The pressure drop of the liquid nitrogen circulation was around 1 kPa for the flow rate of 10 L/min in the experiment. We summarized the experimental results briefly, and estimate the pressure drop of the circulation for a longer cable system (~2 km) depending on the experimental conditions.