Numerical investigations on the effect of asymmetric inlet conditions on the performance variations of centrifugal compressor

Abstract

Abstract The high adoption frequency of inlet bent pipes result in variations between the operating performance and design value. In this paper, the performance of centrifugal compressor while adopting two inlet bent pipes, i.e., Pz and Pu, are simulated through the verified simulation method, respectively, and the flow field characteristics of inlet pipes are analyzed and quantitatively characterized. The analysis shows that centrifugal compressor’s performance with Pz and Pu both decrease to a certain degree. The flow field of symmetric swirling distribution both occurred on the outlet plane of Pz and Pu, and the circumferential distortion degree of plane (PCD) with Pz and Pu shows an increasing trend as the flow rate increases. The PCD of Pz with different rotational speed are always higher than that of Pu. The degradation degree of centrifugal compressor’s performance of Pz and Pu both increase with the increasing of PCD, and it is higher by adopting Pz, the pressure ratio degradation degree reaches 6.82% while it reaches 7.38% in efficiency degradation degree. It is found that there is a power law relation between the degradation degree of pressure ratio and PCD, and an exponential relationship between the efficiency degradation degree and PCD.