Aiming at the abnormal phenomenon of excessive vibration of the medium pressure valve during the oper-ation of a certain type of ultra-supercritical 1000MW unit,the vibration of the medium pressure valve and the shaft system of the unit is tested and analyzed.It is concluded that the vibration of the medium pressure valve is mainly 50Hz,which is close to the rotation frequency of the unit and the natural frequency of the valve.It shows that there is structural resonance in the medium pressure valve,and the excitation source is the medium pressure rotor.Further analysis shows that the main reasons for the structural resonance of the medium pressure valve are the insufficient rigidity of the spring support of the medium pressure cylinder inlet valve group and the uneven load of the medium pressure cylinder.In the overhaul,replace the new medium pressure valve support spring,and improve its preload,improve its stiffness and stability;the load distribution of the medium pressure cylinder block is carried out to improve the stability of the cylinder block,so as to reduce the influence of the vibration of the medium pressure rotor on the valve.After treatment,the vibration of the medium pressure valve of the 1000MW unit is greatly reduced,which improves the safety and reliability of the unit and has a good engineering reference value.
1000MWmedium pressure valvestructural resonancespring supportload distribution
万方数据
维普
