Against the resonant problem in high pressure(HP)and intermediate pressure(IP)rotors in steam turbines

the HP-IP rotor vibration modal of a subcritical 300 MW unit steam turbine was analyzed using numerical simulation software ANSYS

on the basis of the HP-IP rotor structure features.The first 6orders' natural frequency and the critical speed of the HP-IP rotor for this 300 MW unit steam turbine are obtained and the results were compared with that of the steam turbine with normal working speed(3 000r/min).It shows that

generally

the working speed of steam turbine will not reach the last 3orders' critical speed.Therefore

the resonant problem will not occur in the last 3orders.During the practical operation

when the rotor's working speed goes through the first 3orders

it should goes quickly and gets away from the critical speed to avoid the resonant vibration.