[关键词]
[摘要]
为了研究燃气轮机空气管道喷雾冷却过程中流场分布、雾滴运动轨迹及冷却效果,基于欧拉-拉格朗日粒子追踪模型开展了喷雾冷却的数值研究,探究了不同雾滴尺寸、喷水量条件下,进气管道内流场特性、温度分布以及压力损失。模型为实测L型进气管道,横截面尺寸为3 m×8 m,直管段长度为11.6 m,竖直段长度为6.9 m,在直管段的端部均匀布置3×8喷嘴阵列,雾化水温度为15 ℃,喷吹速度为60 m/s,管道空气流速为3 m/s。研究表明:喷嘴雾滴喷入量为零和100%时,出口平面的速度分布标准差分别为0.60和0.71,喷雾对流场分布未产生太大影响;雾滴直径越大在管道内的运动距离越远,汽化长度越长,雾滴直径为50 μm时,完全汽化所需长度达14.05 m;喷雾冷却前后压损率分别为12.55%和8.59%,喷雾后总压损减小,流场改善;随喷水量增大,出口气体含湿量增大,出口温度降低,当喷水量为100%时,降温达12.43 ℃。
[Key word]
[Abstract]
In order to study the flow field distribution,droplet trajectories and the cooling effect in the spray cooling process of gas turbines,the numerical study on spray cooling was carried out based on the EulerianLagrangian particle tracking model. The flow field characteristics,temperature distribution and pressure loss in the air intake pipe under different droplet sizes and water injection conditions were explored. The model is a measured Lshaped intake pipe with a crosssectional size of 3 m×8 m,in which the straight pipe length is 11.6 m and the vertical pipe length is 6.9 m. A nozzle array of 3 m×8 m is evenly arranged at the end of the straight pipe. The atomizing water temperature is 15 ℃,the injection speed is 60 m/s,and the air flow rate in the pipe is 3 m/s. The research results show that when the droplet injection amount are zero and 100%,the standard deviations of velocity distribution at outlet plane are 0.60 and 0.71 respectively. Spray has little effect on the flow field distribution. The larger the droplet diameter is,the farther the movement distance in pipe is,and the longer the vaporization length is.When the spray droplet diameter is 50 μm,the length required for complete gasification is 14.05 m. The pressure loss rates before and after spray cooling are 12.55% and 8.59%,respectively. The total pressure loss decreases and the flow field is improved after spray cooling. With the increase of water spraying rate,the moisture content of the outlet gas increases and the outlet temperature gradually decreases. When the water spraying rate is 100%,the temperature drop can reach 12.43 ℃.
[中图分类号]
TK479,TK124
[基金项目]
中央高校基本科研业务费资助项目(N182504011)