What is eccentricity of 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 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 absolute expansion in steam turbine?

Rotor Expansion on a turbine is the absolute measurement of the rotor’s axial thermal growth with respect to the turbine’s foundation. A typical large steam turbine power generation unit will have a thick case, on the order of 12″ to 18″.

What is TSI in turbine?

A Turbine Supervisory Instrumentation System (TSI) is a sophisticated, customisable digital computer system used in heavy industry to monitor active turbines for potential flaws, faults, and failures.

What is rotor eccentricity?

A rotor eccentricity is a condition of unequal air gap that exists between the stator and the rotor [5]. A dynamic eccentricity occurs when the center of the rotor is not at the center of rotation and minimum air gap revolves with the rotor. This means that a dynamic eccentricity is a function of space and time.

What is turbine rotor eccentricity?

Turbine eccentricity is the amount that the turbine shaft deviates from a perfect circle while in motion. Essentially it is how much it wobbles. Turbine position is sometimes referred to as spindle position and it refers to the horizontal movement of the shaft.

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 shift in steam turbine?

Axial shift on the Rotors comes due to two components. Direct Pressure Thrust: It is the axial thrust due the diff of the pressure X Area component across the moving stage blading and Discs. Velocity Component: It is due to diff.

Which is supervisory instruments used for steam power plant?

Turbine Supervisory Instrumentation (TSI) Systems provide continuous on-line monitoring and machine protection for steam and gas turbine generator sets. The TSI system measures a variety of supervisory parameters to provide reliable machine condition information and alert to any machinery problems.

Which type of compressor is used in a gas turbine plant?

Which type of compressor is used in a gas turbine plant? Explanation: Multistage axial flow compressor is the compressor in practical usage in a gas turbine plant.

What causes rotor eccentricity?

A rotor eccentricity is a condition of unequal air gap that exists between the stator and the rotor [5]. Air- gap eccentricity can occur in the form of static or dynamic eccentricity. A typical cause of a dynamic eccentricity includes bent shafts, mechanical resonances at critical speeds, and bearing wear.

What should the eccentricity of a steam turbine be?

The permissible value of rotor eccentricity below 600 rpm is typically equal to Steam turbines start-ups 173 200 µmp−p. One the threshold is exceeded, automatic trip of turbine takes place. Above 600 rpm rotor relative vibrations should be monitored.

What causes a turbine to stop 180o out of phase?

In extreme cases of thermal/gravity bow, caused by a sudden trip of the unit and failure of the turning gear to engage, the rotor may be positioned and stopped 180o out of phase (bow up) to allow gravity to work entirely on the bow and substantially shorten the time required to reduce the bow.

How is eccentricity measured on a wind turbine?

Eccentricity is measured while the turbine is on slow roll (1 to 240 RPM below the speed at which the rotor becomes dynamic and rises in the bearing on the oil wedge) and requires special circuitry to detect the peak- to-peak motion of the shaft.

What happens during the start up of a steam turbine?

The start-up phase is a particu- larly dangerous and complicated phase of steam turbine operation as it consists of starting numerous equipment and auxiliary systems, and mechanical and thermal processes taking place have nonstationary nature (i.e., transient heating, varying steam flows, acceleration of rotors, vibrations, etc.).