What is axial shift in steam turbine?

Axial shift of a steam turbine is the shifting of turbine rotor in the forward and backward direction due to steam thrust on blades of rotor. Reason is, Sudden change of load. Sudden drop of vacuum.

What is differential expansion in steam turbine?

Differential Expansion on a turbine is the relative measurement of the rotor’s axial thermal growth with respect to the case. Due to the mass of this case, it will expand and contract at a slower rate than the relatively thin (hollow) rotor.

What is float in steam turbine?

Thrust Bearing Float:- It is the total axial movement of the Rotors between the working and the Non working Pads of the Thrust Bearing. It is measured by moving the rotors from the extreme end of the working pads to the extreme end of the Non working pads or vice versa Reading is measured by Dial Gauges .

What is meant by axial displacement?

Axial displacement corresponds to movement in one dimension only along an axis. This means that the object does not rotate in any direction. It only translates in one direction only, for example; from right to left and vice versa, from top to bottom and vice versa, or back and forth.

What is eccentricity in steam turbine?

Eccentricity is the measurement of Rotor Bow at rotor slow roll which may be caused by any or a combination of. Fixed mechanical bow. Temporary thermal bow.

What is linear and superficial expansion?

linear expansion is the increase only in length and superficial expansion is the increase in the area.

What is axial loading?

Axial loading is defined as applying a force on a structure directly along an axis of the structure.

What is eccentricity shaft?

An eccentricity is one of the major factors that affect the entire system by causing whirling of the shaft and premature failure of the shaft at high vibration condition. Such high vibration condition can be controlled by an important technique called vibration-monitoring technique.

What is the axial shift of a turbine?

The axial shift of turbine basically refers to the axial shift of turbine rotor. You would be aware the turbine rotor is subjected to pressure differential as at inlet pressure is more and at outlet it’s less. So because of pressure differential rotor has a tendency to shift at low pressure side which known as axial shift.

What is axaxial shift?

Axial shift is the forward motion created by the applied force, in this case steam. It will be most noticeable during a pressure change, such as start up or shut down. A sudden change during what should be normal operation could be problematic.

Why are the dimensions of a steam turbine rotor different?

The rotor is also subject to axial thrust due to the flow of steam while in operation. Due to manufacturing clearances and Thermal expansion all parts (Both Stator and Rotors) are subject alteration of dimensions. These are different for different parts as materials of construction are different Mountings thrust and reactions also vary.

What is steam turbine?

Steam turbine utilises Steam at high temperature to convert Thermal Energy to kinetic Energy for say Power generation or as a prime mover for other machines. The steam has an effect of expanding all parts of any machine by altering all dimensions. The rotor is also subject to axial thrust due to the flow of steam while in operation.