A forward-curved blade centrifugal compressor for anode recirculation in proton exchange membrane fuel cells

Anode recirculation is crucial for the stable and efficient operation of automotive proton exchange membrane fuel cells (PEMFCs). The circulation is commonly driven by ejectors or positive displacement compressors, rather than centrifugal compressors, which have difficulty overcoming large pressure drops at low flow rates despite their promising attributes such as stable control and smooth operation. To address this gap, the present work proposes a novel design of a magnetically levitated centrifugal compressor featuring forward-curved blades. The comprehensive design process of this compressor is described, incorporating a novel design methodology, numerical simulations, and experimental validation. The compressor operates stably within the low-power range of typical automotive PEMFCs. At the design point, it achieves a static-to-static pressure ratio of 1.10 with an isentropic efficiency of 50 % and a system efficiency of 41 %. The test results demonstrate that the forward-curved blade centrifugal compressor is a viable option for anode recirculation in PEMFCs.