Thermal test of the insulation structure for LH2 tank by using the large experimental apparatus

Conceptual designs of large mass LH2 (liquid hydrogen) storage systems, who se capacity is 50,000 m(3), have been studied in the Japanese hydrogen proj ect, World Energy Network (WE-NET) [K. Fukuda, in: WE-NET Hydrogen Energy S ymposium, 1999, P1-P41]. This study has concluded that their thermal insula tion structures for the huge LH2 tanks should be developed. Their actual in sulation structures comprise not only the insulation material but also rein forced members and joints. To evaluate their thermal performance correctly, a large test specimen including reinforced members and joints will be nece ssary. After verifying the thermal performance of a developed large experim ental apparatus [S. Kamiya, Cryogenics 40 (1) (2000) 35] for measuring the thermal conductance of various insulation structures, we tested two specime ns, a vacuum multilayer insulation (MLI) with a glass fiber reinforced plas tic (GFRP) support and a vacuum solid insulation (microtherm((R))) with joi nts. The thermal background test for verifying the thermal design of the ex perimental apparatus showed that the background heat leak is 0.1 W, small e nough to satisfy apparatus performance requirement. The thermal conductance measurements of specimens also showed that thermal heat fluxes of MLI with a GFRP support and microtherm((R)) are X and 5.4 W/m(2), respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.