Numerical Simulation for Lightweight Design of a Liquid Hydrogen Weighing Tank for Flow Standard

To improve the accuracy of gravimetric liquid hydrogen flow standard devices, the self-weight of the weighing tank must be minimized, because the total mass of the liquid hydrogen contained in the tank is far smaller than the structural mass of the tank itself, which severely compromises the sensitivity of gravimetric measurement. In this study, a three-dimensional finite element model of a vacuum-insulated liquid-hydrogen weighing tank was developed in ABAQUS. The inner and outer shells were modeled with 06Cr19Ni10 (304) and 06Cr17Ni12Mo2 (316) austenitic stainless steels, and Polyamide 6 (PA6) was used for the internal support. Three operating stages were considered: evacuation of the annulus (interlayer pressure reduced from 0.1 MPa to 0 MPa), pre-cooling to −253 °C, and pressurization of the inner tank (internal pressure increased from 0.1 MPa to 1 MPa). The equivalent stress and deformation were compared for different materials and wall thicknesses to evaluate structural safety and weight-reduction potential. The proposed configuration (inner shell 1.6 mm and outer shell 1.0 mm) achieves a mass reduction of more than 50% relative to the 3 mm minimum wall thickness commonly adopted for cryogenic vessels, while keeping stresses below the allowable limits. This reduction enables the use of higher-resolution load cells and thereby lowering the measurement uncertainty of the liquid hydrogen flow standard device and providing technical support for lightweight and cost-effective design, with potential applicability to other cryogenic tank systems.