Abstract:In response to global climate challenges and energy transition imperatives, the advancement of hydrogen fuel cell vehicles featuring high energy efficiency and zero-emission characteristics represents a strategic pathway. Focusing on the development of a two-stage aerodynamic gas bearing centrifugal compressor specifically engineered for a 130kW vehicular fuel cell system, achieving critical performance parameters, including pressure ratio of 2.8, mass flow rate of 130g/s, and operational speed of 88000r/min. A general flow model and a leakage flow model for the two-stage aerodynamic gas bearing centrifugal air compressor were constructed, numerical simulations and comparative analyses of these two models were carried out. The thickness and shape of the impeller back cavity and the geometric number and structural parameters of the annular seal teeth in the leakage flow model were investigated. Performance tests and validation of the air compressor were conducted on an upgraded centrifugal air compressor comprehensive performance test bench. The results indicated that the pressure ratio error of the flow model considering the leakage channel under the design condition was reduced from 10.63% to 5.11%. Appropriately reducing the thickness of the impeller back cavity and increasing the axial dimensions of the seal teeth can reduce gas leakage. The calculation formula of the leakage coefficient with the number of sealing teeth was fitted. The two-stage aerodynamic gas bearing centrifugal air compressor impeller had a high safety margin, its structural strength can meet the requirements of ultra-high speed operation. And the isentropic efficiency of the two-stage aerodynamic gas bearing centrifugal air compressor can reach 73.30% under design conditions, with a maximum stable rotational speed of up to 95000r/min.
