摘要
枞树型叶根广泛应用于燃气轮机和大功率蒸汽轮机叶片,其可靠性严重影响着叶片的安全运行。采用三维热弹性有限元分析技术建立了仅考虑离心力载荷及综合考虑离心力和温度载荷的数值模型,对4种不同的叶根轮缘接触面制造偏差状况下叶根应力进行了详细分析,发现常温下设计良好的枞树型叶根轮缘,在高温下由于热胀导致的变形,将使叶根承载分布不均,从而产生很大的应力,并且应力状况也随着制造偏差而不同。所以在设计高温级叶片枞树型叶根型线时,需要综合考虑叶根的制造偏差以及工作状态下的承载情况进行安全性校核。
Fir-tree root is widely used in blades of gas turbines and large-power steam turbines, and its reliability has serious effect on blade safety. Three-dimensional thermoelastic finite element technique was adopted to analyze the root stress with four cases of manufacturing variation of contact surfaces between root and rim. During the analysis, two cases of load： centrifugal force, general load of centrifugal force and temperature load, were taken into account. The numerical results show that the well-designed fir-tree root and rim under room temperature may lead to high stress during high temperature. The generated uneven distribution load for each tooth of root comes from the deformation created by the thermal expansion under high temperature. In addition, the stress is also much different with manufacturing variations. So it is necessary to consider the manufacturing variations and general load of root to design fir-tree root profile for high temperature conditions.
出处
《热力透平》
2011年第2期103-109,共7页
Thermal Turbine
关键词
汽轮机
枞树形叶根
制造偏差
接触应力
steam turbine
fir-tree root
manufacturing variations
contact stress
