An Investigation of High Loading Centrifugal Compressor Stability Enhancement Using a Vaned Diffuser Recirculation Technique

Abstract

With the continuous improvement of centrifugal compressor pressure ratio, vaned diffuser gradually becomes one of the key factors restricting the stability of centrifugal compressor. A novel vaned diffuser casing treatment has been created to increase the stable operating range at low mass flow rates. This paper employs a parameterization approach to investigate the impact of varying recirculating mass flow rates on stability enhancement via examination of tube diameter in the context of recirculation technology. The results demonstrate that a higher recirculating flow rate allows for operation under lower mass flow rate conditions. Nevertheless, this leads to an increase in flow loss within the diffuser. The increase in stall margin signifies a comprehensive alteration in mass flow rate and total pressure ratio, and serves as a benchmark for assessing the enhancement of the operating range. For a recirculating tube diameter of 1.5mm, the maximum increase in stall margin is 3.21%.