混合室结构对蒸汽喷射器性能的影响

针对蒸汽喷射器引射性能低的问题,采用fluent数值模拟来分析蒸汽喷射器内部流场变化规律,在其他结构保持不变的情况下,通过研究混合室各部分结构来提高引射性能,使蒸汽喷射器在一个稳定且能量耗散较小的结构范围内工作。研究结果表明:引射性能与混合室内的激波变化紧密相关;混合室各部分结构都存在最佳参数值使引射系数达到最大。

Influence of Mixing Chamber Structure on Entrainment Ratio of Steam Ejector: A Simulation Study

The flow field in steam ejector was mathematically modeled and numerically simulated with Fluent software.The influence of the mixing chamber geometry,including its axial length,inlet and throat diameter-ratios,on entrainment ratio was investigated.The simulated results show that the mixing chamber structure has a major impact.Roughly speaking,the entrainment ratio changes in an increase-decrease manner with an increase of either the axial length,or of the inlet diameter ratio,or of the throat diameter-ratio.A throat diameter-ratio,either too large or too small,severely deteriorates the performance of steam ejector.The optimized dimension of mixing chamber includes: a tapered section length of 50 mm,a constant diameter section length of 10 mm,a throat diameter-ratio of 5.63 and an inlet diameter-ratio of 2.22.We suggest that the simulated results be of some technological interest in design of steam ejectors.