10MW氦气轮机涡轮轮盘强度的计算方法

A Method for Calculating the Strength of Wheel Disks of a 10 MW Helium Gas Turbine

以往对涡轮盘进行强度分析都是采用“等厚圆环法”理论进行计算,这样的简化由于没有考虑榫头和榫槽凸块的刚性对传力的影响,因此得到的盘缘部分的应力有时可能误差较大,对轮盘偏心孔和榫齿根部的应力集中都无法进行分析。现在可以通过Pro/E对涡轮盘这样复杂的结构进行实体建模,运用ANSYS进行有限元分析计算,就能获得较精确的应力分析结果。本文采用上述两种方法,针对某型机的某一级涡轮盘连同若干级叶片一起进行计算分析,验证了“等厚圆环法”理论可以从宏观上反映轮盘的受力状态,同时也证明了有限元法各项参数的选择是正确的,为同类型的其它结构进行强度分析提供了技术参考。

To date, the strength calculation and analysis of turbine disks has all along been conducted, using an “equal-thickness ring method' theory. As such a simplification has not taken into account the effect of rigidity of tenon and mortise boss on force transmission, the disk rim stress values thus obtained may sometimes exhibit a sizable error, making it impossible to analyze the stress concentration at the eccentric holes of the disk and at the root of tenon teeth. However, relatively accurate stress analytic results can now be obtained by establishing a real entity model for a wheel disk of complicated structure through the use of software Pro/E and by performing a finite element analysis and calculation, using software ANSYS. By adopting the above-mentioned two methods, calculated and analyzed was a gas turbine disk together with several stages of blades. It has been verified that the “equal-thickness ring method' theory can macroscopically reflect the force-bearing status of the disk. In the meantime, it can be proved that the selection of various parameters for the finite element method is correct, thus providing a technical reference for the strength analysis of other structures of a similar nature.