Design and calculation of sub-critical gas ejector

Study on calculation for entrainment ratio of gas ejecting compressor has been done perfectly.As for sub-critical gas ejector,the same method is taken into account for most of researchers.Aiming at the characteristics of sub-critical gas ejector,three methods of calculation,such as calculation methods for gas ejecting compressor,jet pump and gas ejector,are presented.The research reveals respectively appropriate computation programs of sub-critical gas ejector.With ejector which expansion ratio and compression ratio both are less than critical pressure ratio,elastic influence of the working media can not be ignored when the expansion ratio is a bit large,while the elastic influence of media should be ignored when the compression ratio is a bit small.Based on this,working media can be considered as elastic and ejecting media can be treated as non-elastic when expansion ratio and compression ratio both are close to the critical pressure ratio.Working media and ejecting media should be treated as non-elastic for jet pump calculation when expansion ratio and compression ratio both are close to 1.