Turbine Rolling and Steam Parameters

Vivek Jain

Modern Plant Controls

•Electro-hydraulic Turbine Control System - High Pressure or Low Pressure

•Distributed Digital Control System

•Data Acquisition System•Co-ordinated Master Control

Vivek Jain

Turbine Critical Parameters

• Shaft Vibration < 120 microns• Bearing Vibrations < 40 microns• Differential Expansion • Absolute Expansion 25.4 mm• Axial Shift of Rotor < 0.5 mm• Bearing Temperatures <900C• Turbine Wall Stress Computation -

Temperature & Load Margins

Vivek Jain

Vivek Jain

There are two ways to roll the turbine

• Manual Mode

• ATRS (Automatic turbine run up system)

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TURBINE ROLLING FROM BARRING SPEED

BARRING SPD 240 RPM

GATE VLV GEARING CLSD

540RPM

JOP OFF

600RPM

SOAKING OF HPS & HPC

2850RPM

AOP OFF

3000 RPM SOAKING OF IPS & IPC

TUR TRIPPED

SYNC

AOP-1 ON AT < 2800 RPM

OROIL PR < 4.8 KSC

JOP-1 ONSPD < 510 RPM

GATE V/V GEAR OPN CMD

SPD < 200 RPM

BAR SPD MAINTAINED

AOP-1 FAILS & OIL PR < 4.5 KSC AOP-2 ON CMD.

AOP-1 & 2 FAIL & OIL PR < 1.1 KSC EOP ON CMD.

PR < 95 KSCFOR 8 SEC JOP-1OFF & JOP-2 ON

Vivek Jain

Using ATRSTHERE ARE THREE MODE OF OPERATION:

• AUTOMATIC MODE :WHEN SGC IS SWITCHED TO

“AUTOMATIC ON” & START UP/SHUTDOWN IS INITIATED,THEN STEP IS SET & COMMAND IS EXECUTED IF CRITERIAS FOR THE STEP ARE FULLFILLED.

• SEMI AUTOMATIC : IT ENABLES CONTINUATION OF

PROGRAM STEP BY STEP. ALL CRITERIA FOR A STEP IS SIMULATED BY A SWITCH.IT IS USEFUL WHEN PROGRAM STOPS DUE TO MISSING CRITERIA.

• OPERATOR GUIDE MODE :IN THIS SGC WILL NOT

ISSUE ANY COMMAND ,HOWEVER STEPS WILL PROCEED SEQUENTIALLY.COMMAND HAS TO BE GIVEN MANUALLY BY OPERATOR. Vivek Jain

Manual Mode

• Using EHC

• Using HC

Before going further, it is necessary to review the Governing system in brief…….

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Turbine Governing Oil Circuit

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KWU Turbine Steam Admission

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Vivek Jain

Vivek Jain

Vivek Jain

Vivek Jain

Vivek Jain

Vivek Jain

Vivek Jain

Vivek Jain

Vivek Jain

Vivek Jain

Vivek Jain