Page 589 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

Be st Practice 1 0.12 The Post-Shipment Phase: Installation, Pre-Commissioning, Commissioning and Start-up Best Practices

Fig 10.12.17 -

Principles of operation The Steam chest contains and guides the steam into the turbine
The Steam control valve (not T&T valve) admits steam to the
Component functions:
turbine with a minimum of pressure drop and guides the steam to
Steam Chest & Valves a specific portion of the nozzle block
Nozzles & Blades
Fig 10.12.20 Component Functions
Rotor & Bearings
Steam Seals
Start-up and Shut-down precautions

Fig 10.12.18 Session Topics

The nozzles accelerate the steam velocity from approx.
300KM/HR to 1100 KM/HR
Please refer to Fig.10.12.16
The steam enters the rotor blades (buckets) at 500 KM/Hr
An expansion turbine uses high velocity gas (1100 KM/HR) and turns the rotor
to turn the rotor blades at approx.500 KM/HR.
The higher the pressure drop across the turbine, the higher
Since the most common gas is water vapor (steam)! the produced power and vice versa
However, steam is hot (800°F) and we must slowly heat up
and cool down the turbine to prevent rubs The lower steam temp., greater erosion

Fig 10.12.19 Principles of Operation Fig 10.12.21 Component Functions cont.

560