蒸汽喷射器用双喷嘴结构性能的数值研究

运用CFD数值模拟的方法研究了第二喷嘴进出口截面大小对喷射效率的影响,并对比研究了不同工作流体压力下普通喷嘴结构和双喷嘴结构对蒸汽喷射器操作性能的影响。计算结果表明,在相同的操作条件下,双喷嘴结构能有效地提高喷射器的喷射系数。同时,第二喷嘴进出口截面以及第二喷嘴出口长度存在一最佳值,对应于最大喷射系数。并且这种喷嘴结构能有效改善由于工作流体压力降低而造成的设备操作性能恶化,提高蒸汽喷射器运行的稳定性。

Numerical simulation of steam ejector with double nozzles

A CFD method was applied in the present study to investigate the performance of a steam ejector with double nozzles on different inlet and outlet section area ratio. Further comparison work was conducted between a circular nozzle and double nozzles to reveal the effect of changing the pressure of the primary (motive) steam on entrainment ratio. The results indicate that the double nozzles improve the performance of steam ejector effectively compared with a circular nozzle on the same operation. Also, there is an optimal entrainment ratio for the double nozzles with variable inlet and outlet area ratio and outlet length of second nozzle in a given operation. This trpe of double nozzles has favorable effect in improving the ability and the stability of steam ejector, especially, for lower primary steam pressure.