ABSTRACT
Liquid hydrogen (LH2) is a clear, colorless, mobile liquid. The properties that are most important in its storage and handling are its low boiling temperature (20.3 K at standard atmospheric pressure), low density (70 g/1 or 1/14th the density of water), and high volatility. If the hydrogen is liquefied with no catalyst being used to speed up the conversion from ortho to parahydrogen within the liquefier, the product obtained will have substantially the same composition as it had at room temperature and is referred to as normal hydrogen. Even if catalysis occurs in the liquefaction process, it is not necessarily complete, and any residual excess of orthohydrogen will still give off heat as it converts to parahydrogen. More recently, LH2 storage Dewars in sizes of 100 1 and larger have been built with multilayer insulation. The chapter discusses the sources of heat, insulation systems, and structural materials of the storage Systems, and the design and construction of the transfer systems.
