Session: 37-05 Radial Turbomachinery Design

Paper Number: 127981

127981 - Adaptation of Air Centrifugal Compressor Stages for Hydrogen-Based Economy: Impact on the Design Point and its Corresponding Flow Coefficient 

Transitioning towards a hydrogen-based economy would require many existing air-ready centrifugal compressor stages to operate in hydrogen mode. This shift from air to hydrogen operation in established air-ready centrifugal compressors results in notable changes on the design point and its corresponding flow coefficient. These alterations arise due to distinct gas properties, difference in pressure ratio, outlet temperature, and the fact that these machines are originally optimized for air mode.

The design point flow coefficients for the analyzed air-driven centrifugal compressor stages spanned from 0.04 to 0.1, however there is an urge to predict the corresponding range for hydrogen mode of these machines.  Therefore, this paper aims to comprehensively investigate the impact of shifting from air to hydrogen mode on the design point and its corresponding flow coefficient. The transition has been analyzed by developing a comprehensive methodology that integrates 1D mean line analysis and computational fluid dynamics (CFD). The investigation has been carried out on five different centrifugal compressor stages at a wide range of flow coefficients. The maximum operational rotational speed of the individual stages has not been exceeded to ensure that they remain structurally feasible.

The findings derived from the simulation results suggest that air-ready centrifugal compressor stages, when operated with hydrogen, experience a shift in the best point flow coefficient. This mode shift leads to a decrement in the optimum flow coefficient; hence the corresponding hydrogen design point flow coefficient of the analyzed air designed stages is in the range of 0.02-0.08. An investigation to analyze the flow coefficient dependency on fluid molecular mass and other factors is carried out to explain the findings. Then, the hydrogen optimum flow coefficient can be used for the 1D mean line calculation of each individual air-ready centrifugal compressor stages for hydrogen mode.  

Presenting Author: Mushfiq Al Arafa Fraunhofer UMSICHT

Presenting Author Biography: Name: Mushfiq Al Arafa

Institution: Fraunhofer UMSICHT

Email Address: mushfiq.al.arafa@umsicht.fraunhofer.de

Authors:

Norman Kienzle Fraunhofer Insitute UMSICHT
Mushfiq Al Arafa Fraunhofer UMSICHT
Francesca Di Mare Ruhr-Universität Bochum
Marcus Budt Fraunhofer UMSICHT