| 摘要 |
PURPOSE:To enhance cooling and eliminate the need for liquid nitrogen or a cold insulation tank, by providing a shield plate cooling pipe which has one end communicating with the upper part of the interior of a liquid hydrogen tank heat-insulated by vacuum and covered with a shield plate, surrounds the outer periphery of the tank and has the other end adapted for exhaust, a vacuum pump disposed at an intermediate part of the cooling pipe, and a heat exchanger. CONSTITUTION:With a vacuum pump 5 operated, gaseous hydrogen is made to flow through a shield plate cooling pipe 1 in the direction of an arrow 7. A shield plate 2 is cooled, thereby cooling a liquid hydrogen tank 10 through radiation. The gaseous hydrogen having passed through the cooling pipe 1, with a slight rise in the temperature thereof, is again heated by a heat exchanger 8a to normal temperature, before being exhausted via a pneumatic valve 6. Evacuation of the tank 10 and pressurizing are carried out by opening and closing the valve 6. Because the liquid hydrogen tank 10 is cooled by use of the hydrogen gas generated from liquid hydrogen contained in the tank 10, there is no need for liquid nitrogen or for a cold insulation tank using liquid nitrogen. |
