蒸汽喷射压缩器的操作状态

Operational modes of steam-jet ejector

采用有限体积法离散控制方程,标准k-ε湍流模型,近壁面处使用壁面函数修正的方法对蒸汽喷射压缩器的超音速混合过程进行数值模拟。计算并分析了工作蒸汽压力和温度、引射流体压力及混合流体压力等热力参数对喷射器操作性能的影响,并根据喷射器内的物理现象及喷射系数的变化规律将蒸汽喷射压缩器的操作状态分为临界状态、亚临界状态和回流状态3类,同时指出临界点为最佳工作点。

A finite volume scheme was applied to solve the axisymmetric Navier-Stokes equations and a standard k-ε turbulence model was used to close the governing equations. The performance of steam-jet ejector was investigated by changing the primary fluid pressure and temperature, the secondary and the compressed fluid pressures. The ejector performance is divided into three operational modes according to the physical meanings and the variations of entrainment ratio, that is, critical mode, sub-critical mode and reversed-flow mode. And the critical point is the optimum working point.