What control room indication would you observe then what would you do if while operating at full load on 100% fuel oil one of the burner pumps tripped?
OBSERVATIONS
- burner pump trips target
- fuel flow decreases about 50%
- throttle pressure pilot dropping
- load decreasing
- boiler master driving toward maximum
- fan controls driving toward maximum
- Combustion Control valve driving toward maximum
- drum level dropping
OPERATOR ACTIONS
- acknowledge alarms
- verify stand by pump is set for normal start and start it
- take unit off load control and begin dropping load
- during load drop use the pilot drum level to dictate how far and fast
- observe boiler master, fuel, and air controls to be functioning correctly. if not place controls to manual only as necessary.
- when unit is stable inform Production Leader, FPDC and System Operation
- when stand by burner pump has finished start up cycle place the unit back on control
What control room indications would you observe and what would you do if while operating at full load one of the circulating water pumps tripped.
OBSERVATIONS:
- circ. pump trip target, breaker green lamp, discharge valve green lamp
- condenser vacuum decreasing
- exhaust hood temperature increasing
- check condenser air valves are closed on tripped pump side
OPERATOR ACTIONS:
- acknowledge alarms
- take unit off load control and begin dropping load
- have “inside” operator get hogging jet in service
- while dropping load use the vacuum, pilot, and rum level to dictate how far and fast
- observe boiler master, fuel, & air controls to be functioning correctly. If not place controls to manual only as necessary
- when unit is stable inform Production Leader, FPDC and System Operator
What control room indications would you observe and what would you do if while operating at full load one of the boiler feed pump tripped?
OBSERVATIONS:
- boiler feed pump trip target
- boiler feed pump runback target
- load decreasing
- throttle pressure pilot increasing
- drum level decreasing
- running feed pump or drum level control driving toward maximum
OPERATOR ACTIONS:
- acknowledge alarms
- if automatic runback is not functioning take unit off load control and lower load using the drum level and pilot to dictate how fast and far
- observe boiler master, fuel, & air controls to be functioning correctly. if not place controls to manual only as necessary
- adjust firing patterns in response to fuel pressure demands
- When unit is stable inform Production Leader, FPDC and System Operator
What control room indications would you observe then what would you do if while operating at full load on of the fan sets tripped?
OBSERVATIONS:
- fan trip target
- air flow decreases about 25%
- fuel flow dropping to match air flow (fuel- air cross limiting)
- possible combustibles and opacity
- throttle pressure pilot dropping
- boiler master and remaining fan controls driving toward maximum
- drum level dropping
OPERATOR ACTIONS:
- acknowledge alarms
- if automatic runback is not functioning, take unit off load control and begin to drop load
- observe boiler master, fuel, & air controls to be functioning correctly. If not place controls to manual only as necessary
- during load drop use the pilot and drum level to dictate how far and fast
- when unit is stable inform Production Leader, FPDC and System Operator
What are the common causes of turbine vibration?
- turbine rub
- turbine imbalance
- water induction
- high eccentricity at roll
- low oil temperature (
What is eccentricity?
- bowing of the turbine shaft
What is the limit for eccentricity?
- less than 3 mils for one hour
What causes turbine differential expansion?
- turbine rotor and shell heating at different rates, reducing the clearance between stationary and rotating parts
What are the action limits for turbine vibration?
If turbine is rolling at a speed less than 800 rpm:
- trip turbine immediately if journal bearing vibration exceeds 5 mils
If turbine is rolling between 800 - 2450 rpm:
- trip turbine after any journal bearing vibration exceeds 7 mils for two minutes
- trip turbine immediately if journal breaking vibration exceeds 10 mils
If turbine is rolling between 2450 - 3600 rpm or on the line:
- trip turbine if any bearing vibration exceeds for 15 minutes
- trip turbine immediately if bearing vibration exceeds 10 mils
- vibration level acceptable for continued operation is 5 mils
If you were in a “Rotor Long” condition what could you do to lessen the differential?
- rotor long- reduce load ramp rate of hold load, reduce superheat and reheat steam temperature
What action would you take if at 600 MW’s gross, the voltage regulator starts swinging the VARS and Voltage of the Generator?
- on the Panel Mate Generator Monitor Screen, touch the Mode Select Button. Two pop up buttons will appear. Touch the “Put Regulator in Manual Button” This will place the Voltage Regulator in manual
- notify division within 30 mins that the voltage regulator is in manual
- fill out a NERC log
How is a generator Voltage maintained with the voltage regulator out of service?
- on the Panel Mate Generator Monitor Screen, touch the 70-CS Select Manual Button. two pop up buttons will appear. Raise Manual and Lower Manual. Adjust as needed
Explain how to shutdown the Voltage Regulator
- open the Generator Breaker. On the Output Control Screen, touch the AC Breaker Button. Two pop ups will appear. Touch the Trip 41A Button.
