高压涡轮主动间隙控制机匣内部换热特性试验

针对高压涡轮叶尖主动间隙控制(ACC)机匣中的典型换热结构,利用试验研究了多层机匣结构中内斜向冲击射流的局部换热特征,重点分析了进口雷诺数(10 000~24 000)、冲击孔入射角度(30°,45°,60°)、冲击孔直径(1.0,1.5,2.0mm)等参数对带肋机匣表面局部和平均传热系数的影响规律.研究中发现加强肋的存在显著影响了机匣表面局部传热系数,同时由于冲击射流局部强化换热作用,多层机匣内表面不同位置的传热系数相差很大.试验结果表明:随着冷气进口雷诺数的增加,机匣加强肋表面局部和平均传热系数均提高.在研究参数范围内,冲击孔直径为2.0mm,孔数为23的情况下能够获得最佳的换热效果;相比30°和60°冲击孔入射角度,冲击孔入射角度为45°能获得更好的换热效果.

Experiment on heat transfer characteristics inside the casing of high pressure turbine with active clearance control

According to a typical heat transfer structure of the casing of a high pressure turbine with active clearance control system,experiments were conducted to investigate the local heat transfer characteristics of a mutillayer casing structure.In the experiments,the inlet Reynolds number (10000-24000),the angle of jet impingement (30°,45°,60°) and the diameter of jet impingement hole (1.0,1.5,2.0mm) were changed to investigate the local and average heat transfer coefficients of the casing surface with ribs.It was found that the existence of the ribs affected the local heat transfer coefficient of the casing surface significantly.At the same time,due to the local heat transfer enhancement by the jet impingement,the heat transfer coefficient of the casing inner surface varied considerably at different locations.The results show that the local and average heat transfer coefficients are improved with the increasing inlet Reynolds number of cold air.Within the range of research parameters,maximum heat transfer can be obtained when the diameter of the jet holes is 2mm and the number of jet holes is 23.Compared with the angle of jet impingement 30° and 60°,45 ° can result in higher heat transfer rate.