二维流动模型的喷射器性能分析研究

Numerical study of ejector performance with two-dimensional flow model

采用二维轴对称流动模型 ,计算分析了吸入通道内回流现象、喷射器“恒能力”现象与静压力在轴线上分布情况之间的关系 ;探讨了工作压力对喷射器性能的影响。结果表明 :持续降低出口压力会在混合室内形成激波 ,喷射因数保持不变 ;工作压力过高会在混合室内产生壅塞 ,反而降低喷射因数 ;吸入压力过低会在喷射器吸入通道内产生回流现象 ,影响喷射式制冷系统运行的安全性。

Two-dimensional axis-symmetry compressible model was set up to study the relationship of the recirculation in the suction chamber, ejector constant capacity and static pressure distribution along the axis. The ejector performances under different working pressures were analyzed. It is shown that because of the shock in the mixing chamber the ejector capacity will not increase as continuously decreases the discharging pressure. The ejector ratio begins to drop when the working pressure was high because of the shock in the mixing chamber. Low suction pressure results in recirculation in the suction chamber, which will influence the security of the ejector refrigeration system.