Capacitive density measurement for supercritical hydrogen

[摘要] A new approach for automotive hydrogen storage systems is the so-called cryo-compressed hydrogen storage (CcH2). It has a potential for increased energy densities and thus bigger hydrogen amounts onboard, which is the main attractiveness for car manufacturers such as BMW. This system has further advantages in terms of safety, refueling and cooling potential. The current filling level measurement by means of pressure and temperature measurement and subsequent density calculation faces challenges especially in terms of precision. A promising alternative is the capacitive gauge. This measuring principle can determine the filling level of the CcH2 tank with significantly smaller tolerances. The measuring principle is based on different dielectric constants of gaseous and liquid hydrogen. These differences are successfully leveraged in liquid hydrogen storage systems (LH2). The present theoretical analysis shows that the dielectric values of CcH2 in the relevant operating range are comparable to LH2, thus achieving similarly good accuracy. The present work discusses embodiments and implementations for such a sensor in the CcH2 tank.

[发布机构] Technische Universitaet Dresden, Bitzer Refrigeration, Cryogenics and Compressor Technology, Dresden; 01062, Germany^1;BMW Group, Germany^2

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Automotive hydrogen storage system;Car manufacturers;Compressed hydrogens;Cooling potential;Dielectric values;Liquid hydrogen storage;Operating ranges;Pressure and temperature