船舶燃气轮机冷却涡轮叶片内部带肋冷却通道颗粒沉积特性研究

Particle Deposition Characteristics on Internal Rib Cooling Channel of Air-Cooled Turbine Blade for Marine Gas Turbine

关键词:  船舶燃气轮机  肋倾角  流动换热  颗粒沉积  内冷通道

Key words:  Marine gas turbine  Rib angle  Flow and heat transfer  Particle deposition  Internal cooling channel

摘要:

为了探究船舶燃气轮机冷却涡轮叶片内部冷却通道内肋片角度的改变对颗粒沉积特性的影响，以7种不同肋片角度及1种弯头处加导流片的肋结构作为研究对象，运用CFD数值模拟对比分析各种冷却结构的流动换热性能以及颗粒沉积特性。结果表明：当肋片角度改变时，内部通道的流动换热和弯头壁面的沉积率存在很大差异。肋片角度为45°的内部冷却通道的换热性能相比于换热性能最差的E型肋的平均努塞尔数高了25%；肋片角度为60°时，弯头壁面和弯头后壁面的沉积率最低；肋片角度为90°时沉积率最高；肋片角度为135°时换热性能最差，弯头壁面沉积率最低。肋片角度的改变对弯头侧壁的沉积率和各个部分的撞击率无显著影响，但是增加导流片可以有效降低弯头壁面的捕获率和沉积率以及弯头侧壁的沉积率、撞击率和捕获率。

Abstract:

In order to explore the effect of rib angle on flow and heat transfer and deposition characteristics on internal rib cooling channel of air-cooled turbine blade for marine gas turbine， ribs with seven kinds of different angles and a rib with guide vane applied in the elbow were selected as the research object， and the CFD was used for numerical simulation to analyze their performance of heat transfer and particle deposition. The results indicate that there is a great difference between the heat transfer performance in the channel and the deposition rate on the elbow wall when the rib angle is changed. When the rib angle is 45°， the heat transfer performance is the best， 25% higher than the average Nusselt number of E-type rib with the worst heat transfer performance. The deposition rate on the elbow wall and the back wall is the lowest when the rib angle is 60°. The deposition rate is the highest when the rib angle is 90°. When the rib angle is 135°， the performance of heat transfer is the worst， and the deposition rate on the elbow wall is the lowest. Change of the rib angle has no significant impact on the deposition rate for the elbow side wall and the collision rate. However， the guide vane can effectively reduce the capture rate and the deposition rate on the elbow wall， and reduce the deposition rate， collision rate and capture rate on the elbow side wall.