Abstract:

The complex internal flow field of steam ejector was numerically simulated with commercial software FLUENT. The pressure and velocity variation of internal fluid in the flowing process were studied and analyzed. The influences of the mixing steam pressure and the outlet diameter of primary nozzle on the ejector performance of the steam ejector were discussed in a great length. It is found from the results that the entrainment ratio of the steam ejector remains constant first with the back pressure to its critical pressure and then decreases, nevertheless, the entrainment ratio initially increases sharply with the primary nozzle outlet diameter and then decreases after the outlet diameter exceeds a certain value. Therefore there exists a critical outlet pressure for the steam ejector that determines its operation states. The outlet diameter of main nozzle has an optimal range, in which the ejector obtains the best performance, and the dissipation loss of the shock wave is relatively small.

Key words: steam ejector, mixed steam pressure, primary nozzle outlet diameter, entrainment performance, shock wave, process systems, model, numerical simulation

摘要：

利用FLUENT软件对蒸汽喷射器复杂的内部流场进行数值模拟计算，并对喷射器内部流体流动过程中压力、速度等参数的变化规律进行分析研究，重点讨论了混合蒸汽压力和主喷嘴出口直径的变化对蒸汽喷射器引射性能的影响。结果表明：蒸汽喷射器存在一个临界出口压力，主喷嘴出口直径存在一个最优范围，此时喷射器的引射性能达到最佳，而且激波的耗散损失较小。

关键词: 蒸汽喷射器, 混合蒸汽压力, 主喷嘴出口直径, 引射性能, 激波, 过程系统, 模型, 数值模拟