Double structure tube for cryogenic fluids and dual structure storage tank for cryogenic fluids

摘要

A double-structure fluid tube for cryogenic fluids includes an inner tube through which a cryogenic fluid flows, and an outer tube which is externally fitted to the inner tube with a sealed, tubular space therebetween. An inactive gas having a melting point and a boiling point each at least equal to a temperature of the cryogenic fluid is filled in the tubular space between the inner tube and the outer tube. When the cryogenic fluid flows through the inner tube, the inactive gas is liquefied or solidified, and therefore a layer of liquefied inactive gas and / or a layer of solidified inactive gas is formed on an outer peripheral surface of the inner tube. As a result, a pseudo-vacuum layer substantially in a vacuum state is formed in the tubular space.