Thermodynamic analysis and optimal design of the sub-cooled liquid hydrogen centrifugal pump for hydrogen refueling station

In a sub-cooled liquid hydrogen refueling station, the centrifugal pump is the most critical component to pressurize the liquid hydrogen into a subcooled state to achieve efficient storage. The thermodynamic behavior of the pump significantly affects its subcooling level and efficiency, but the response mechanisms are lacking. Therefore, the thermodynamic model incorporating heat transfer, turbulence, cavitation, and cryogenic liquid hydrogen is presented. Quantitative influence and percentage contribution of critical structural factors to the head and isentropic efficiency by signal-to-noise ratio and analysis of variance are investigated. Multi-optimization is conducted by grey relational analysis. Results suggest that the head increases with the increase of outlet width, axial length, and number of blades, while decreasing with the leading edge. The isentropic efficiency first increases and then decreases with the increase of outlet width, axial length, and leading edge, while decreasing with the increase in the number of blades. Largest percentage contributions are identified as 53.10% at the leading edge and 34.03% at the blades number for the head and isentropic efficiency, respectively. Considering both higher head and efficiency, the preferred combination consisting of the outlet width of 3.6 mm, axial length of 10.6 mm, leading edge of 10 mm, and number blades of 8 is determined. Compared to average values, the head and isentropic efficiency are improved by 14.49% and 0.18% for the combination. These findings provide novel insights into enhancing the efficiency and subcooling of sub-cooled liquid hydrogen centrifugal pump for refueling stations.