Experimental study on the influence of diffuser and inlet guide vane for the performance of centrifugal compressor

An experimental study was conducted to investigate the performance of the centrifugal compressor under different diffuser stagger angles and different inlet guide vane (IGV) prewhirl angles in order to find the way of the optimum matched means of the IGV and vaned diffuser. In this experiment, it is found that the performance can be altered largely by adjusting the IGV prewhirl angles and diffuser stagger angles. In addition, the performance is quite sensitive to the negative prewhirl angle and small positive prewhirl angle of IGV when the diffuser stagger angle is reduced to its minimum value. Moreover, the maximum efficiency with simultaneous adjustment of the IGV prewhirl angle and the diffuser stagger angle can achieve. Furthermore, the optimum match between the IGV prewhirl angle and the diffuser stagger angle is a function of flow rate and the pressure ratio.