Answer / dspatel10

turbine shaft material has own natural frequency. when turbine rotate on such a speed that freq. of shaft becomes close ti its natural freq., thereby causing noise and high vibration in the machine because of the resonance. shaft becomes dynamically unstable and large vibration is developed . it occurs at a speed called critical speed.

Answer / pradeep.m

If system frequency (Turbine shaft frequency) match with natural frequency resonance will occur.So turbine vibration is more at that period of speed. That speed is known as critical speed of the turbine.

Answer / vamsi balayapalli

At start up turbine rotates slowly upto reach 3000rpm, at one perticular speed shaft frequency matches with natural frequency due to that resonance condition high vibrations and noise . Normally 1600rpm is critical speed for 210mw thermal unit

Answer / damotharan

It is the speed at which the machine vibrates most violently. It is due to many causes, such as imbalance or harmonic vibrations set up by the entire machine. To minimize damage, the turbine should be hurried through the known critical speed as rapidly as possible. (Caution, be sure the vibration is caused by critical speed and not by some other trouble).

Answer / kousik karmakar

Only 210MW C speeds is 1585.1881.2017.2489.4500 rpm

Answer / naser

2733RPM

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