| 摘要 |
PROBLEM TO BE SOLVED: To provide an on-vehicle superconducting transformer which is capable of reducing the replenishment of refrigerant in frequency so as to make its maintenance operation simpler. SOLUTION: In this superconducting transformer 1, provided that the boiling point (-195.8 deg.C), solidifying point (-209.9 deg.C), normal operating temperature, and specific heat of liquid nitrogen are represented by Tb, Ts, Tr, andρrespectively, furthermore the amount of liquid nitrogen kept in a cryostat 8 is represented by W, the amount of steady heat penetration into the cryostat 8 is represented by Q, and a time when a vehicle is shut off from a power supply is represented by (t), the superconductive transformer 1 is so set as to satisfy following formulas, Tb>Tr>Ts, W>(Q×t)÷[(Tb-Tr)×ρ]. By this setup, even if a power supply-free time (t) becomes comparatively long, a temperature rise in liquid nitrogen can be reduced so as to keep the temperature of liquid hydrogen lower than the its boiling point Tb. Therefore, this superconducting transformer 1 is not required to be frequently replenished with liquid nitrogen, so that its maintenance operation becomes simpler. |
