蒸汽/空气两种介质在涡轮叶片中冷却性能对比的试验研究

Comparative Experiment of Cooling Performance in a Turbine Blade Cooled by Steam and Air Flow

搭建了高温风洞环形叶栅试验台,分别对冷却叶片通蒸汽和空气进行冷却,利用红外热像仪测量叶片吸力面在这2种冷却介质冷却下的温度分布,并对这2种冷却介质冷却下的叶片的冷却性能进行了对比,研究表明:蒸汽冷却相对于空气冷却并不能明显改变叶片表面冷却效率分布特征,但是蒸汽冷却下叶片表面的冷却效率得到提高,相对温度明显降低,在流量比ω=0.026的设计工况下,叶片吸力面前部区域的平均冷却效率在蒸汽冷却下比空气冷却时提高了15.5%,相对温度降低0.011,叶片吸力面后部区域蒸汽冷却平均冷却效率比空气冷却提高了13.4%,相对温度降低0.017。相对于传统的空气冷却技术,蒸汽冷却的优势十分明显。

An annular cascade test was conducted in a high temperature tunnel. One blade in the annular cascade was respectively cooled by super-heated steam and air. The temperature distributions on the suction surface of the blade cooled by the two coolants were both measured by an infrared camera, and the cooling performance of the two coolants was compared with each other. Results show that： the steam cooling does not significantly change cooling efficiency distribution on blade surface, but the cooling performance for steam flow is obvious better than that for air flow. For example, in the design working condition of flow ratio ω =0.026, the area-averaged cooling efficiencies of the front part and rear part of the suction surface are respectively increased by 15.5% and 13.4% in steam cooling than that in air cooling. At the same time, the relative temperatures of the two parts are reduced by 0.011 and 0.017, respectively. Comparing with traditional air cooling in blade, the advantages of steam cooling are very obvious.