摘要
考虑非线性密封激振力、可倾瓦轴承的弹性支承力、转子阻尼力、转子不平衡力与重力,建立超超临界600MW汽轮机高中压转子-密封系统的非线性动力学模型。该非线性转子-密封系统动力学方程组具有超大规模的维数,采用Newmark数值积分方法对其进行求解,模拟出运行在正常工况下与最大工况下转子不平衡响应与汽流激振的特性;对转子不平衡量和密封流体的周向平均流速对汽流激振现象的影响规律进行分析。结果表明:在一定的范围内,不平衡量大小对发生汽流激振的失稳转速影响很小;密封内流体周向平均速比是影响汽流激振的失稳转速的主要因素,适当减小密封内流体周向平均速比可提高汽流激振的失稳转速;超超临界机组运行在最大工况下高中压转子发生汽流激振的失稳转速明显低于正常工况下的失稳转速。
The nonlinear dynamic model of HP-IP rotor-seal system for an ultra-supercritical 600 MW steam turbine was established, in which the non-linear seal-excited force, the elastic support force of tilting-pad bearing, the damping force of rotor,imbalance force and gravity were considered. Using Newmark numerical integration method, the dynamics equations with large-scale dimension were solved. The unbalance response and seal-excited vibration characteristics of rotor were sim- ulated at normal and maximum operating conditions. The effects of unbalance of rotor and average circumferential velocity of seal fluid on seal-excited vibration were examined. The results show that the unbalance of rotor has little influence on the threshold speed of seal-excited instability; appropriately reducing average circumferential velocity of seal fluid can improve the stability of the system by increasing the threshold speed;the threshold speed of seal-excited instability of HIP rotor at maximum operating conditions is significantly lower than that at the normal operating condition of ultrasupercritical steam turbine.
出处
《润滑与密封》
CAS
CSCD
北大核心
2011年第4期4-7,72,共5页
Lubrication Engineering
基金
国家自然科学基金重点项目(10632040)
关键词
转子-密封系统
不平衡响应
密封激振
超超临界汽轮机
rotor-seal system
unbalance response
seal-excited vibration
ultra-supercritical steam turbine
