600MW汽轮机叶轮偏心汽流激振力分析与模拟

Analysis and Simulation of Stream-exciting Force Caused by Impeller Eccentricity in 600 MW Steam Turbines

以某发电厂超临界600 MW汽轮机转子为研究对象,根据蒸汽做功原理对动叶流道处的动偏心激振力进行了分析.在围带汽封处采用CFD软件模拟涡动转子泄漏蒸汽的三维黏性流场,确定了汽流激振力.计算结果表明:在不对称进汽工况下,转子将受到较大的静态汽流力;当采用对称进汽时,汽流激振力很小,有利于提高转子的稳定性;与额定工况比较,在阀门全开(VWO)工况下,径向激振力的增幅很大,而切向激振力和泄漏量的增幅却很小,表明大型汽轮机采取对称进汽方式可以提高转子运行的稳定性.

Taking a rotor of 600MW supercritical steam turbine as studying object, the dynamic eccentric exciting force at the flow path of the rotor blade were analyzed based on the principles of steam doing work. The forces excited by steam flow were identified by simulating the 3-D viscous flow field with CFD software for whirling rotor＇s steam leakage at shroud steam seal. Calculation results show that the rotor will be subjected to larger static exciting force in asymmetric inlet condition. In symmetric inlet condition, the exciting force is quite little, that is benefit to rotor stability. Compared with the rated conditions, there is a big increase in radial force but a less increase in tangential force and leakage under the valve wide open （VWO） conditions. Consequently, for the large scale steam turbine, the stability of rotor system will be enhanced in symmetric inlet condition.