核电汽轮机围带摩擦阻尼定量计算方法

Quantitative Calculation Method of Shrouds Friction Damping in Nuclear Power Steam Turbine

针对目前由于无法定量计算核电汽轮机围带阻尼而只能凭经验设计叶片围带结构等技术难题,以四边形围带为例,基于谐波平衡法建立考虑摩擦系数、接触角、接触刚度、间隙、转速影响的围带宏观滑移迟滞摩擦模型,基于CN群论建立考虑围带内阻尼和刚度的转子系统动力学模型,提出利用瞬态响应幅值包络法定量计算不同工况下围带等效阻尼新方法。研究表明,摩擦系数、接触刚度、转速、间隙、接触角对围带内阻尼影响的敏感性依次降低;围带摩擦等效阻尼在工作转速下达到最优;应用所提出的等效阻尼计算法可优化围带各参数获得最优内阻尼自愈抑振效果,对指导转子系统设计具有重要意义。

In view of the fact that the shroud damping can't be calculated quantitatively and the technical problems of the blade shroud structure can only be designed empirically, taking the quadrangle shroud as an example and basing on the harmonic balance method, a macro-slip hysteresis friction model considering the effect of friction coefficient, contact angle, contact stiffness, clearance and rotational speed was established,basing on the theory of CN group, a dynamic model of rotor system considering the internal damping and stiffness of the shroud was established, a new method of calculating shroud equivalent damping under different working conditions with transient response amplitude envelope method was proposed.The results show that the sensitivity of friction coefficient, contact stiffness, rotation speed, clearance and contact angle to the internal damping are reduced in turn,and the equivalent friction of the shrouds achieves the optimum at the working speed,the internal damping energy consumption increases and the vibration of the rotor system can be effectively restrained,the proposed equivalent damping calculation method can optimize the shroud parameters to obtain the optimal internal damping self-healing and anti-vibration effect, which is of great significance to the design of the rotor system.