为了提高涡轮外环的冷却效果，本文基于涡轮外环实际工况多变的特性，搭建了两种燃气进角（90°、167°）的外环冲击/气膜冷却试验台，利用红外测温技术试验研究了气膜孔排布方式、燃气进角、吹风比（0.7、1.0、1.5、2.0、2.5、3.0）、温比（1.2、1.3、1.4、1.5、1.6）对冲击-气膜冷却式外环冷却特性的影响。结果发现：气膜孔垂直或同向燃气来流出气的气膜覆盖效果好于对冲燃气出气的气膜覆盖效果；较90°进气，167°进气外环表面的冷气覆盖区域得到扩展，面平均综合冷却效率提升1.03%~12.6%；外环综合冷却效率因吹风比增大使冷气流量、压力增大而增加，对应增加率介于1.04%~9.96%，而温比增大提升主流加热能力导致外环冷却效率降低，最大降低率达到11.04%。
Abstract
Based on the variable characteristics of the actual operating conditions of the turbine shroud and the purpose of improving the cooling effect of the turbine shroud, this paper builds a test system of the impingement-film cooling shroud with two gas inlet angles (90°, 167°). The effects of film cooling hole arrangement, gas inlet angle, blowing ratio (0.7, 1.0, 1.5, 2.0, 2.5, 3.0) and temperature ratio (1.2, 1.3, 1.4, 1.5, 1.6) on the cooling characteristics of the impingement-film cooling shroud were experimentally studied by infrared temperature measurement technology, especially the effects of gas inlet angle and temperature ratio. The results showed that the film covering effect of the film cooling hole vertical or the same direction of the high-temperature gas incoming flow is better than the film covering effect of the reverse direction with the incoming flow, and the optimal arrangement of film cooling holes can improve the cooling effectiveness of the shroud. Compared with 90° intake gas, the film coverage area on the shroud surface of the 167° intake gas is expanded, and the surface average overall cooling effectiveness is increased by 1.03% to 12.6%. The overall cooling effectiveness of turbine shroud increases with the increase of blowing ratio, which increases the flow rate and pressure of cooling gas, and the corresponding increase rate is between 1.04% and 9.96%. However, the increase in the temperature ratio increases the mainstream heating capacity, resulting in a decrease in the cooling effectiveness of the shroud, with a maximum reduction rate of 11.04%.
关键词
turbine shroud /
overall cooling effectiveness /
impingement-film cooling /
blowing ratio /
temperature ratio
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Key words
turbine shroud /
overall cooling effectiveness /
impingement-film cooling /
blowing ratio /
temperature ratio
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脚注
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基金
The authors are grateful for the supported by China Postdoctoral Science Foundation (NO. 2020TQ0147), Natural Science Foundation of Jiangsu Province (NO. BK20200454), and the Fundamental Research Funds for the Central Universities (NO. NJ2020014).
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版权
Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2022
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