流量比对高位预旋进气涡轮转静盘腔换热影响的数值研究

Numerical Study on Effects of Inlet Flow Ratio on Heat Transfer in Turbine Rotor-Stator Disk-Cavity with High-Positioned Pre-Swirl Inflow

关键词:  涡轮转静盘腔  数值模拟  入口流量比率  努塞尔数  温度均匀性

Key words:  Turbine rotor-stator disk-cavity  Numerical simulation  Inlet flow ratio  Nusselt number  Temperature uniformity

摘要:

为提高冷气与涡轮盘的换热效果，针对高位预旋30°进气的转静腔耦合涡轮盘系统进行了数值模拟，研究了不同转静腔入口流量比率和转速对系统换热效果的影响，并对涡轮盘壁面平均努塞尔数Nuˉ、盘体最高温度、盘体温度均匀性进行了分析。结果表明：转速为1×10⁴r/min时，随着转静腔1和2的入口流量比率P从1增加到6，左壁面Nuˉ稍有上升，右壁面Nuˉ先增后减，在P=3时最大；盘体最高温度降低，且P<3时降幅较大，之后较小。盘体温度均匀性受P影响较小，P>2后，左右两侧径向温度均匀性几乎一致，轴向温度均匀性均优于径向，盘缘处轴向温度均匀性最差，越靠近轴心均匀性越好。在转速为6×10³~1.2×10⁴r/min时，随转速增大，系统换热效果增强。当转速<1×10⁴r/min时，随P增大，冷气与涡轮盘之间换热不断改善；转速>1×10⁴r/min后，P在3附近综合换热效果较好。

Abstract:

Numerical simulation was carried out for a rotor-stator cavity coupling turbine disk system with high-positioned pre-swirl inflow of 30° to improve the heat exchange effect of cool air and the turbine disk. The influence of inlet flow ratio and rotational speeds on the heat exchange effect of system was investigated， and the Nuˉ of the turbine wall， maximum disk temperature and disk temperature uniformity were analyzed. The results show that when the rotational speed is 1×10⁴r/min， with the inlet flow ratio P of the rotor-stator cavity 1 to 2 increasing from 1 to 6， the Nuˉ on the left wall slightly increases. The Nuˉ on the right wall increases to the maximum when P is 3 and then drops. The maximum disk temperature decreases dramatically when P is lower than 3， and then decreases slightly. The disk temperature uniformity is less affected by P. When P is greater than 2， the radial temperature uniformity on the left and right wall is almost the same. The axial temperature uniformity is always better than the radial temperature uniformity. The axial temperature uniformity at the disk rim is the worst， which turns better， near the axis. When the rotational speed is 6×10³~1×10⁴r/min， the heat transfer between the cool air and the turbine disk is enhanced with increasing the rotational speed. When the rotational speed is less than 1×10⁴r/min， the heat transfer effect of the system improves continuously with the increase of P. The heat change effect is optimal when P is around 3 for the rotational speed is more than 1×10⁴r/min.