EDM Flashcards
emergency Diesel Mechanical (37 cards)
STATE the number of cylinders, continuous load rating, and operating speed of Seabrook’s emergency diesel (DG) engines
- 16 cylinders
- 514 rpm
- 6083 kW
EXPLAIN the operations which occur in a cylinder during the DG four stroke cycle
- INTAKE (Induction)
- COMPRESSION
- POWER
- EXHAUST
LIST the five major mechanical support systems associated with the DGs
- Starting and Control Air System
- Intake, Exhaust and Crankcase Vacuum Systems
- Fuel Oil System
- Lube Oil System
- Cooling Water System
STATE the purpose of the DG starting air system
To air start the EDG
DESCRIBE the operation of the DG starting and shutdown air system component Air Receivers
- 2 parallel receivers sized to allow for 5 engine starts
- If one should fail, the other can start the diesel twice.
- Pressure is automatically maintained between 560 and 600 psig by the Main Air Compressor
DESCRIBE the operation of the DG starting and shutdown air system component Main Air Compressor (including auto ops)
• Maintains receiver pressure by cycling on and off to maintain 560-600 psig.
DESCRIBE the operation of the DG starting and shutdown air system component Air Start Solenoids
• Provide an actuating control air signal to the Main Air Start valves and the Rack Boost 3-way valves
DESCRIBE the operation of the DG starting and shutdown air system component Barring Device Interlock
• Physically prevents pilot control air from the Air Start Solenoids from reaching the Main Air Start valves
DESCRIBE the operation of the DG starting and shutdown air system component Main Air Start Valves
• When provided with actuating air from the Air Start Solenoids, these valves provide starting air to the Air Start Distributors
DESCRIBE the operation of the DG starting and shutdown air system component Rack Boost 3-Way Valves
• Ports control air to the starting side of the fuel rack boost cylinder, provided all required conditions are met
DESCRIBE the operation of the DG starting and shutdown air system component Air/Oil Foggers
• Prevents degradation of the Air Start Distributor by supplying a thin mist of lubrication when starting the diesel
DESCRIBE the operation of the DG starting and shutdown air system component Air Start Distributors
• The admission of starting air to a particular cylinder is controlled by an air start distributor for each bank and is driven by the engine camshaft
DESCRIBE the operation of the DG starting and shutdown air system component Air Start Check Valves
• The air start distributors, driven by the engine camshafts, send pilot air signals to the air start check valves in each cylinder head
DESCRIBE the operation of the DG starting and shutdown air system component Stopping Air Accumulator
• Ensures that an adequate volume of air is maintained to actuate the rack boost servo piston in the event that both air receivers are inoperable
DESCRIBE the operation of the DG starting and shutdown air system component Shutdown Solenoid
• The Shutdown Solenoid allows control air to be ported to the shutdown side of the shutdown/rack boost piston, forcing it and the connected engine fuel rack to the shutdown position
DESCRIBE the operation of the DG starting and shutdown air system component Rack Boost Piston
• Actuates to move fuel racks to required position to maintain desired engine speed, or to drive the fuel racks to the shutdown position when engine shutdown is called for.
STATE the design basis for the volume of the starting air receivers
Combined can start the diesel 5 times or twice for a lone receiver
DESCRIBE the purpose and basic operation of the DG engine turbocharger
• Increase density of air for combustion make engine more efficient
DESCRIBE the FO flowpath from the oil truck connection to the DG cylinder
- Truck
- FOST
- Duplex strainer
- FO XFER Pumps
- FO Day Tank
- Duplex strainer
- Fuel Pumps
- Filters
- Injector Pumps
- Injectors
- Casing
STATE the design basis for the volume of the FO storage tank and FO day tank
• Fuel oil storage tank – 75,000 gallon tank – Tech spec minimum is 62,000 gallons – Good for 7 days operation • Day Tank – 1500 gallon capacity – 3 hours full load
STATE the power sources for the FO transfer pumps and each of the DG FO pumps.
- Fuel Oil Pumps Power supply: 1A is MCC-511 and 1B is MCC-611.
- Fuel Oil Transfer Pumps Power supply: 1A is MCC-521 and 1B is MCC-621
DESCRIBE the operation and purpose of the DG lube oil (LO) system
The Diesel engine lube oil system supplies a continuous flow of oil to all engine surfaces
requiring lubrication, and to the piston crowns for cooling
DESCRIBE the operation and purpose of the Engine Driven LO Pump
- The Engine Driven LO pump is a positive displacement, rotary screw type pump mounted below the engine governor drive.
- Normal source of oil pressure for the engine
DESCRIBE the operation and purpose of the Motor Driven LO Pump
(including auto ops)
• The Aux LO pump has the same capacity and suction point as engine pump and acts as a backup.The motor driven pump will automatically start if the outlet
pressure from the duplex fuel filter drops to the low pressure alarm setpoint (15 psig)
