以船舶燃气轮机完整排气引射系统为研究对象,采用标准k-?模型模拟计算,分析了基准工况流场特性和温度分布特性,在此基础上探索了恶劣工况下,开启冷却风机后不同风机压头对排气引射系统流场特性的影响。研究表明:与基准工况对比,冷却进气质量流量随压力阶跃的增加而增加,冷却进气量增加使混合管道内温度更加频繁与均匀,局部高温区更小,出口温度更低,基准工况时无量纲出口温度为0.5150,而200Pa压头时为0.5099；随着风机压头的提升,排气引射系统的总引射量和总引射系数也随之提高,在1500Pa工况下达到最大值,相较于基准工况,总引射系数提高了17%；喷管进口的总静压均会随着压头增加而增大,排气引射系统出口温度也持续降低,阶跃压力从200Pa增加到1500Pa的过程中,无量纲温度从0.5099下降到0.4771。

Taking the complete exhaust ejector system of marine gas turbine as the research object, the standard k-? model simulation calculation is used to analyze the flow field characteristics and temperature distribution characteristics of the baseline condition, and on the basis of which the influence of different fan pressure-head on the flow field characteristics of the exhaust ejection system after turning on the cooling fan in the severe working condition is explored. The results show that compared with the reference condition, the mass flow rate of cooling inlet increases with the increase of pressure step, the temperature in the mixed pipe becomes more frequent and uniform, the local high temperature zone is smaller, and the outlet temperature is lower. The dimensionless outlet temperature is 0.5150 in the reference condition, while it is 0.5099 in the 200Pa head. With the increase of the fan pressure-head, the total mass entrainment and the total mass entrainment ratio of the exhaust ejector system also increase, reaching the maximum value under the 1500Pa, compared with the reference condition, the total mass entrainment ratio increases by 17%; the total and static pressure of the nozzle inlet increases with the increase of the pressure-head, and the outlet temperature of the exhaust ejector system continues to decrease, and the dimensionless temperature decreases from 0.5099 to 0.4771 when the pressure step increases from 200Pa to 1500Pa.