轴向排汽汽轮机中低压汽缸稳定性数值模拟研究

Numerical Simulation Investigation on the Stability for ILP Cylinder of an Axial Exhaust Steam Turbine

采用三维有限元数值模拟方法,建立某轴向排汽汽轮机中低压缸模型,计算了汽缸在不同运行载荷工况下汽缸的变形及汽缸猫爪承受的支反力,从而判定汽缸稳定性水平。数值模拟结果表明,该类型中低压缸稳定性受排汽温度和轴向推力的影响较大,为保证中低压缸稳定性,避免动静间隙变化导致碰磨,应保证汽缸的设计刚度,同时现场运行应严格控制排汽温度,避免超温。

A three-dimensional finite element numerical simulation method was used to establish a model of the ILP cylinder of an axial exhaust steam turbine.The deformation of the cylinder under different operating load conditions and the support reaction forces of the cylinder claws were calculated to determine the stability level of the cylinder.The numerical simulation results indicate that the stability of the cylinder is greatly affected by exhaust temperature and axial thrust.To ensure the stability of the cylinder and avoid friction caused by clearance changes of rotating and stationary parts,the design stiffness of the cylinder should be large enough,and the exhaust temperature should be strictly controlled during operation to avoid over-temperature.