Section Review Flashcards
(51 cards)
State the service flows in the gas turbine area
Fuel gas, instrument air, potable water, river water, hydrogen, nitrogen, CO2, service air
State why a turbine has an over speed trip
To prevent damage to the turbine and generator in case of failure of the other safeguards.
For the following problems state the causes and any corrective action required. Also state the results if corrective action is not taken.
A. Lube oil temp is slowly trending down.
B. Lube oil temp is slowly trending up.
A. Corrective action- Too many fans are on or control valve is open also you should see excessive bearing vibration, check other bearings, check lube oil temp in field, ccw flow/temp, and ccw valve position.
B. Corrective action- turn on fin fans and close control valve. Causes- hi bearing vibration, bearing to burn up, check other bearings, line oil temp, ccw flow/temp, and similar equipment.
State the function of the following equipment in the closed cooling water system.
A. Fin fans
B. Ccw circulation pumps
A. Fin fans pull air across finned tubes to cool the water
B. Circulate the cooling water through the cooling water header
State the equipment that is cooled by the CCW system.
Lube oil coolers, sample coolers, air coolers, flame detectors, turbine support legs, and hydrogen coolers
What do we use for make up on the CCW system?
Polished water glycol mix, can use river water as back up.
Describe how the nitrogen pad is controlled.
By a regulator
State the normal level of the CCW surge tank
75-80%
we run 10-15%
State the normal CCW pressure
60-70psi
Describe the purpose of the auto/smart on the CCW pumps.
Low pressure will start the pumps in auto
The CCW pumps are cavitating discuss cause and effects of this problem.
Cause- loss of suction or water is vaporizing inside pump casing.
Effect- This damages the impeller.
Describe actions you would take if a fin fan breaks its belt.
Red tag the switchgear, enter work order, locate correct belt, sign on master, and change the belt. Test before walking away to ensure it isn’t vibrating or an alignment issue
Describe your actions if you get a hi temp alarm on the inboard bearing on the HP boiler feed pump and the control valve is at 100%
Check for proper oil flow, check the CCW system isn’t leaking and working properly, turn on more fin fans
Describe the function of each of the following gas turbine lube oil system equipment
A. Lube oil accumulator
B. Surge tank
C. Auxiliary surge tank
Lube oil accumulator- absorbs the shock or surge of oil durning start up/ shutdown of pumps.
Surge tank- 500 gallon tank used to reduce surge and receive oil from #2 bearing.
Aux surge tank- 250 gallon tank interconnected to the surge tank, reduces surge and receives oil from #3 bearing.
State why the following items on the lube oil system should be checked on a routine round.
Reservoir level and temp
Oil spills and leaks
Filter differential
Oil presser and temp
Pump switch positions
Cooling water and valve positions
Reservoir level and temp- check for proper level and temp
Oil spills or leaks- nothing is leaking or draining oil.
Filter differential- make sure filters aren’t plugged
Oil pressure and temp- it’s at normal operating temp and pressure
Pump switch positions- make sure they’ll start in emergencies.
Cooling water valve position- make sure the ccw operating properly
State what action you would take on a low lube oil level alarm.
Add more oil from 8001 and check for leaks.
State what effect a high oil temp would have and what you would need to do to correct the oil temp.
Bearings will burn up. Make sure ccw valve is open, turn on fin fans
State what effect a high filter differential will have and what you would need to do to correct the problem.
Low oil pressure due to plugged filters. Switch over to other filters and replace the plugged ones.
State the source of the 90# steam for fire protection and how it is activated.
LP superheater suction of HRU
Snuffing steam located on wall outside load compartment
Name the two primary hazards associated with the gas turbine fire protection system.
CO2- suffocation
90# steam- thermal burn
Who must be notified any time a portion of the fire protection system is taken out of service
Fire and security
State the function of the fallowing valves associated with the GT fuel gas system.
A. Auto gas vent valves
B. Manual vent valve
C. Control valve
D. Fuel gas block valve
A. Vents durning start up shutdown
B. Depressurize the header when shutting down
C. Controls gas to burners
D. Blocks FG header
State why the fuel gas valve to the GT should always be closed when the turbine is not running.
To prevent FG from entering the system and causing a fire or explosion.
State the consequences of low fuel gas header pressure
Can’t start the turbine and you’ll loose load on turbines running.
