A large experimental apparatus for measuring thermal conductance of LH2 storage tank insulations

In the Japanese hydrogen project, WE-NET (World Energy Net Work), the conce ptual design of the large mass liquid hydrogen storage systems for ground t anks and transportation, whose scales would reach to that of commercialized LNG (liquid national gas), has been studied. This study has concluded that the thermal insulation for a mass storage tank, providing the excellent th ermal performance with the optimized strength, should be developed. In orde r to evaluate thermal conductance of various devised insulations, we have m anufactured a large-scale experimental apparatus. This apparatus, which ado pts a double guarded flat plate boil-off calorimeter method, can provide th e thermal data needed for designing a full-scale tank. It would be possible to test various kinds of specimens with allowable dimensions: diameter 120 cm, thickness up to 30 cm. In the case of a rigid specimen contacting bott om surfaces of liquid hydrogen vessels, the good flatness of their bottom p lates is desirable to reduce the thermal resistance between vessels and a s pecimen surface. This paper describes the abstract of the developed apparat us, its structural design and also the experimental results for verifying i ts structural design. (C) 2000 Elsevier Science Ltd. All rights reserved.