SBOGS (GT) Flashcards
1
Q
What does 10CFR50.63 require for SBOGS ?
A
Section 50.2:
1.)Each light water cooled nuclear plant must be withstand and recover from a station blackout
2.) Reactor core and associated coolant,control,protection,station batteries must provide sufficient power for containment integrity during blackout
2
Q
How does 10CFR50.2 define a station blackout?
A
-Defined as a complete loss of AC power to essential & nonessential switchgear buses
3
Q
What does a PVNGS blackout look like ?
A
-Loss of offsite power to class buses,and coincidentally loss of both Class Diesel Generators
4
Q
What is the PVNGS coping time for station blackout ?
A
Has a 16hr coping time based on voluntary license conditions
5
Q
What is the Main Purpose for the SBOGS ?
A
-To provide AC power within 1 hour of station blackout
-Provides sufficient capacity and reliability to operate systems required for the 16 hour station blackout coping time
6
Q
What is the minimum continuous output rating for each SBOG ?
A
-3,400kW
-13.8kV
7
Q
When do the SBOGS normally operate ?
A
-Station Blackout
-Operators discretion during a LOOP
-A loss of normal power to the MCC supplying power to SBOG control system
-System testing
8
Q
What’re the goals for the Loss Of Offsite Power/ Loss of Forced Circulation procedure ?
A
-Mitigate effects of LOOP or LOFC
and
-Maintain plant in hot standby or hot shutdown
or
-Establish shutdown cooling system entry conditions
while
-Minimizing radiological release to environment and maintaining adequate core cooling
9
Q
How is ,standard appendix 57,performed during a Loss of Off-Site Power and Failure of a Single Diesel generator?
A
-Align SBOG to a vital bus either,PBA-S03 or PBB-S04, to provide power to class battery chargers
10
Q
What are the goals for the Station Blackout procedure ?
A
-Restore availability of vital components
and
-Safety establish entry conditions of the LOOP/LOFC emergency operating procedure or procedure provided by TSC
while
-Minimizing any radiological release to the environment adequate core cooling
11
Q
What Standard appendices does the station blackout procedure direct you towards to supply power to coping loads?
A
-Standard appendix 80- Align SBOG to PBA-S03
One SBOG is analyzed to supply station blackout loads on A Train
-Standard appendix 81- Align SBOG to PBB-S0
B-Train non-design basis SBO scenario
12
Q
What is the Station Blackout procedures strategy ?
A
-Bring plant to stable conditions and restore vital auxiliaries
13
Q
What is the first major action of the Blackout procedure ?
A
-Ensure safety equipment that don’t rely on AC power to function
-Aux. FW pump to maintain SG level and use of ADVs for heat removal
-Next steps would be to restore electrical power
14
Q
What is the second major action of the Blackout Procedure Strategy?
A
-Ensure the plant is coping with the loss of power
-This includes maintaining RCS cooling by a limited controlled cooldown
15
Q
If offsite power or diesel generator are not expected to restore power within 4 hours, where will the Blackout Coping strategy direct you ?
A
-Will be directed to do a Controlled cooldown to Shutdown Cooling Entry conditions to be started
16
Q
If power isn’t restored from offsite or diesel generators within 8 hours, what will the Blackout Coping Strategy direct you to do ?
A
-Will direct Spent Fuel Pool Cooling to be restored
17
Q
Operators will restore enough electrical capacity to allow for what ?
A
-Allow for transition from Blackout Coping Strategy to either the Loss of Offsite Power procedure or another procedure directed by TSC
18
Q
During a license basis SBO, what’re the two objectives that operator actions are expected to achieve ?
A
-Establish power to 1 of the Class 4.16kv trains.
-Maintain natural circulation of NSSS until power is restored
19
Q
There are circumstances in Both LOOP procedure & Blackout procedure that have you perform Standard Appendix 54,what does the appendix 54 have you perform ?
A
-Align SBOG to NAN-S05 to supply switchyard loads (unit1 only)
-Align SBOG power to NAN-S01, then to NGN-L13 to supply ‘EF’ battery charger to power NKN-M45 for control power to trip NAN-S05 breakers to protect SBOG from switchyard faults
20
Q
What is the theory of a Gas Turbine engine ?
A
-Engine that converts chemical energy into mechanical energy using air a medium of conversion
-Mechanical energy created is used to drive rotor of an electrical generator
21
Q
What’re the 4 processes that comprise Brayton Cycle ?
A
-Compression:Atmospheric air drawn into compressor
-Combustion: Fuel injected into compressed air creating fuel/air mixture,which is then ignited creating rapid expanding gases
-Expansion: Expanding hot gases are directed into turbine to turn shaft
-Exhaust :Gases discharge to atmosphere
22
Q
What’re the major package components attached to the skid base frame?
A
-Gas Turbine Engine
-Speed-reducing Gearbox
-AC generator
-Interconnect shaft that connects the turbine to the AC generator
-Package enclosure
-On skid Gage panel
-Auxiliary equipment:
Start system
Fuel system
Lube oil system
23
Q
What are the features built into the Skid Base frame ?
A
-Lube oil reservoir & support for smaller components of auxiliary support system
-Connections are around perimeter of the frame for Fuel,Oil,Instrument air, communications,& other services
24
Q
What’re the features of the SBOG package enclosure ?
A
-Steel enclosure rests on skid base frame
-Reduces noise levels
-Protects equipment from harmful weather
-Provides enclosed space for fire protection
-Isolate heat generated form human work environments
25
Describe the doors on the SBOG enclosure.
-Sealed removable panels
-Hinged doors for easy access
-doors incorporate external locking safety handle & may be operated inside enclosure as well
26
How does ventilation work on the enclosure?
-Louvered shutters at inlet/outlet
-inlet draws air through filter and silencer
-Exhaust is discharged through exhaust silencer
27
When does the ventilation system start/stop?
-Starts when the engine is started
-Stops when the engine is shutdown when the enclosure temp. Reaches set point
28
Why must the enclosure doors be closed while the SBOG is running ?
-Maintain proper ventilation & cooling
29
Why should you be careful when you open doors when engine is running ?
-Enclosure Ventilation Fans maintains positive pressure inside closure
-Be cautious when opening enclosure doors while running for doors being opened rapidly
30
What happens if fire happens in enclosure ?
-Contains protective equipment for Fire Detection and suppression system
-Enclosure ventilation dampers will close to contain discharged CO2
31
What are the Enclosures two space heaters for ?
-Prevent buildup of moisture in the enclosure
-Protects generator insulation windings from moisture
32
What indications do the Enclosure Gauge Panel have ?
-Engine LO temperature
-Engine LO pressure
-Engine LO filter D/P
-Engine compressor discharge pressure
-Air accumulator pressure
-Engine Fuel Oil pressure
33
What switches does the panel have ? What’re the switches used for ?
-Two position switch(Starter load& bypass/auto)
-Two push buttons (Crank on & Crank Off )
-They’re used to manually start Diesel Starting Engine to run associated air compressor to pressurize Air Accumulator
34
What major components does the Turbine Engine consist of ?
-Air inlet assembly
-Air Compressor Assembly
-Compressor Diffuser Assembly
-Combustion Assembly
-Turbine assembly
-Exhaust assembly
35
Explain the Air Inlet Assembly ?
Atmospheric air drawn into 3 stage filtration system Screen,filter,silencer:
Screen-Protects from leave,insects,moisture
Filter-20pre-filters & 20high efficiency filters protect from dirt, dust, and debris
Silencer-Uses baffles to dissipate sound
36
Where Air Compressor Assembly located ?
-Bolted to the aft face of the air inlet assembly
-Contains 12 stage axial flow compressor
37
How does the compressor work ?
The stages in the compressor correct the deflection in the air and straighten the flow of air going towards the diffuser
38
What is compressor surge ?
-Pressure ratio across compressor becomes greater than the compressor is able to support at given rotor speed
-Compressor forward stages will produce more compressed air that the aft can handle
39
When is compressor surge most likely to happen ? What happens during compressor surge ?
-Happens at lower compressor speeds during starting & stopping
-Build up of compressed air happens at final compression stages and if severe enough may flow backward through compressor
40
What’re the two ways to avoid compressor surge ?
-Variable Guide vanes
-Bleed Air Valve
41
What are the Variable Guide Vanes used for ?
-installed first stages of compressor used to match low pressure forwards stage to the high pressure rear stages
-Changing of vane position changes volume of air entering compressor
42
What is a Variable Stator Vane used for ?
Is an electro-mechanical system consisting of inlet Guide Vanes and the first 3 rows of stator vanes
43
What’re the two positions the Variable Stator Vane system works in ?
-At startup & low rpm’s they’re at minimum open position restricting incoming air
-Vanes begin to open at 90% speed and are fully open in 2seconds allowing full air flow into turbine
44
What is the Bleed Air Valve used for ?
-During low engine speeds,helps reduce excess volume of air in the engine to prevent engine compressor surge
-Maintains T5 average temp.(3rd stage turbine rotor temp) within 5degrees
45
How does the Bleed Air Valve work ?
Diverts excess air from discharge of compressor and bypasses combustion and turbine section, straight to the exhaust
46
Where is the Compressor Diffuser located at ? What is the diffuser used for ?
-Stationary casing located at the aft of the compressor section
-used for larger flow path for air exiting compressor,reducing its velocity& giving final pressure increase
47
What is the first 25% primary air used for ?
-It is mixed with fuel for combustion
48
What is the other 75% of secondary air used for ?
-Used to cool combustion gases and inner heat shield
-keeps flame come from touching liner
-Ensure complete combustion and reduces gas temp PRIOR to entering turbine section
49
What does the external combustion assembly support ?
-Fuel injectors
-Fuel Manifold
-Igniter torch
-Bleed Air Valve
-Thermocouples that measure 3rd stage turbine inlet temp
50
What does the internal combustion assembly support ?
-Supports combustion chamber
-Turbine Nozzle housing
51
How many fuel injectors protrude around the combustion chamber ?
12 fuel injectors
52
What is each injector supplied with ?
Supplied with air assist connection to atomize fuel for better ignition
53
What is the Igniter torch used for ? When does the ignitor torch turn off ?
-It is used to ignite the fuel/air mixture during startup
-Igniter is turned off when engine becomes self-sustaining (66% engine speed)
54
What is 2/3 of the power generated used for ? What is the remainder of the power used for
-Used to drive engine compressor & accessories
-Remainder of power is to drive Gearbox & Generator
55
What’re the nozzles used for in the turbine section ?
-Nozzles funnel accelerate the expanding combustion gas to enter next turbine rotor blades at increase velocity
56
What is the air that is tapped off the 11th stage of the compressor for ?
It gets sent to the turbine rotor blades of the 1st & 2nd stage
57
What is the Exhaust Diffuser for on the exhaust assembly ?
-Helps reduce the velocity of the gases from the turbine section by have an expanding volume flow path
58
What is a Exhaust Collector used for in the Exhaust assembly ?
-Provides expanding path which collects and redirects exhaust gas flow & also further reduced velocity
59
What is an exhaust bellows for on the exhaust assembly ?
-installed between exhaust collector and downstream exhaust ducting to allow thermal expansion
60
What inside the Exhaust Stack is used for on the exhaust assembly ?
-An exhaust silencer to reduce noise
-Rain stack is used to prevent rain water from collecting whole engine isn’t running
61
What is the T5 temperature ? How is it measured ?
-Temperature of gases entering the 3rd stage Turbine rotors
-Measured by multiple thermocouples installed at 3rd stage nozzles
62
What’re the signals for T5 averaged for ?
They’re averaged for Engine Temperature control
63
What T5 the primary indicator of ?
-Engine loading
-Control limit to which the engine will normally be controlled
64
What happens to T5 if generator loading goes up ?
T5 will go up with the engine loading
65
What happens if T5 limit is reached ?
Control system will restrict fuel flow to prevent engine from exceeding limit
66
What happens if T5 temperature is greater than 1340degrees Fahrenheit for 10 seconds ? What happens after 20 seconds ?
-An alarm will be generated on 10 seconds
-SBOG will trip after 20 seconds
67
Where is T5 Average displayed ?
Displayed on HMI screen, along with each individual thermocouple value
68
What is P2 mean ?
-P2 is the pressure of the air exiting the engine compressor in the diffuser section
-Also known as Pcd(compressor discharge pressure )
69
What does Pcd represent ?
-Represents mass flow of air entering combustor
-Primary indicator of engine power
70
What does a high Pcd mean ?
-Means more fuel can be mixed and combusted to provide an increase in releases energy, and thus output power
71
How does the control system use the Pcd signal ?
Control system used Pcd signal to help schedule fuel flow during certain phases of operation
72
What is Pcd a good indication for besides compressor discharge pressure ?
-Good indication of cleanliness and condition of engine compressor,should be monitored by operator to help predict routine maintenance
73
Where is Pcd displayed at ?
HMI screens
74
What is the SBOG reduction gear used for ?
Reduction Gear Unit is used to REDUCE turbine output shaft speed to the lower input speed required by generator
75
What kind of gear arrangement is the reduction gear ?
It’s an epicyclic high-speed star gear arrangement
76
What is the output speed of the reduction gear ?
-Output speed is 1800rpm and 60HZ
77
What is reduction ratio of the Reduction Gear ?
~8.3/1
Turbine speed=14,951rpm,
Generator speed=1800rpm
78
What commoners does the Reduction Gear provide mounting for ?
-Engine Lube Oil Pump
-Starter Motor
79
What is the main purpose for the SBOG generator ?
Convert mechanical energy produced by turbine into electrical energy
80
What is the three phase AC generator output rated for ?
kV output :14.2kV
kW output:4270kW
@.8 Lagging power factor
81
What’re the design basis loads ?
-Using a HPSI pump on a single SBOG is 3364.3kW
-Using two charging pumps on a single SBOG 2699.4kW
82
What’re the main components of the generator ?
-Stator
-Rotor
-Exciter
-Permanent Magnet Generator
83
What is the stator used for ?
Has theee stator windings in generator casing and as magnetic field from rotor passed over it induces voltage into stator windings
84
Where does the output leads from the three stator windings go to ?
Connected to power distribution system in the Generator terminal box
85
What is rotor used for in the generator ?
-Need a rotating magnetic field to induce voltage onto stator
-Magnetic field on rotor controls the output voltage of the generator
86
What does the Exciter do for the generator ?
Provides DC current to induce voltage onto the rotor which controls output voltage of generator
87
What does the Permanent Magnet Generator do for the generator ?
-Produces a voltage to provide power for the voltage regulation system
88
When does the Permanent Magnet Generator start producing power ?
-As soon as generator begins to rotate
-Generator does NOT need external initial excitation or field flashing
89
How is the PMG and Exciter all put together ?
Generator rotation rotates PMG on exciter end of the shaft and induces single phase output into PMG stator winding, this AC output is then rectified into DC by Voltage Regulation system, which is then fed to exciter, then gets induced into rotor
90
PMG power is supplied through relay contacts which are open during early stages of start sequence, when will the relay contacts close ?
They will close on 80% engine speed
91
Why do the relay contacts close when engine speed reaches 80% ?
To prevent voltage build up in generator causing drag on engine acceleration during early start sequence
92
How is the generator stator winding and rotor windings cooled ?
Achieved by circulating air from fans on both end of generator drawing in air & exhausted out through top of generator
93
What is the SBOG Hydraulic Start system main purpose for ?
Provides engine rotation from standstill to self sustaining engine speed (66%Ngp)
94
What’re the major components of Hydraulic Start system ?
-Diesel Engine
-Hydraulic pump
-Hydraulic Starting Motor
-Hydraulic Oil Filters
-Hydraulic Oil Reservoir
-Hydraulic Accumulator
-Starter Engage Solenoid Valve
-Starter Adapter Housing
-Sprag Clutch Assembly
95
What kind of diesel engine is on the SBOG ?
Turbo charged, fuel injected that is started by a 24VDC Diesel Starter Motor
96
When will the Diesel Starter Motor be actuated ? What is the Motor powered from ?
-Actuated by a start signal from control system
-Motor is power by a 24VDC Start Batteries located in SBOG control room
97
What’re the diesel engines two functions upon SBOG startup ?
-Drives an attached air compressor to pressurize Turbine Engines Air Assist Accumulator up to 120psig at Engine startup
-Also supplies rotational power to drive hydraulic pump which is used to start rotation of Engine
98
Where does the diesel engine receive it fuel from ?
Supplied from Diesel Start Engine Fuel Oil Day Tank mounted outside of enclosure
99
What level is the Start Diesel Engine Fuel Oil Day Tank required to be maintained at ?
Tank is required to be filled >70% at all times
100
Where does the Diesel Start Engine Fuel Oil Day Tank receive its fuel from ?
Diesel Start Engine Fuel Oil Day Tank fill line taps off of Fuel Oil tanks for the SBOGS
101
What does the hydraulic pump do for the Hydraulic Start system?
-Supplies pressure needed to drive hydraulic motor
-Incorporates a integral low pressure gear type charge pump to prime servo system and transmission lines during startup. Ensures positive pressure at pump and motor when flow is demanded
102
What is piston stroke length of the high pressure pump determined by ?
Determined by the angle of the variable swash plate
103
What is the Hydraulic Starting Motor used for on the Hydraulic starting system ?
-Hydraulic Motor cranks turbine engine through overrunning sprag Clutch and Reduction Accessory Gear Unit
104
Where is the Hydraulic Motor mounted on ?
Mounted on Reduction Gearbox/accessory drive which rotates the engine by means of overrunning sprag clutch
105
What is the Hydraulic Oil Filters used for on the Hydraulic Start system ?
Prevents containments from damaging Hydraulic Pump,Hydraulic Motor, and other components of Hydraulic Start system
106
Where are the Two Oil filters installed at ?
-One filter is downstream of Supply Oil Start Transmission Pump and maintained cleanliness of servo system
-Second filters is on return line to reservoir
107
What happens if Hydraulic Filters become clogged ?
There is a bypass in each filter that will open on high D/P and actuate alarm
108
What features does the Hydraulic Oil Reservoir have ?
-Level gauge
-Level switch
-Fill point with integral filter
-Temperature monitor
-Heater to maintain >50F
109
Where is the Hydraulic Start System Oil Reservoir located at ?
Located below the Generator
110
What is Hydraulic Accumulator used for on the Hydraulic Start system ?
Located downstream of hydraulic pump to maintain pressure during pressurization and depressurization transients
111
What is the Starter Engine Solenoid Valve used for on the Hydraulic Start system ?
Is energized by 24VDC from control system to control the transmission of hydraulic pressure to the Starter Motor during start sequence
112
What is Starter Adapter Housing used for ?
Attached to reduction gear box/accessory drive gearing to provide connecting and mounting of hydraulic motor to engine
113
What is Sprag Clutch Assembly used for on the Hydraulic Start System ?
Interconnected with shaft within Starter Adapting Housing to transfer Starter Motor torque to Reduction Gearbox/accessory drive gearing
114
When will the Sprag Clutch disengage from Accessory Gearbox ?
Clutch will disengage when Engine speed is self-sustaining (66%Ngp), Turbine Engine will continue accelerating on its own
115
What components does Lube Oil system lubricate and cool ?
-Turbine Bearings
-Gear Unit Bearings
-Generator Bearings
Carries heat from Engine during operation and for a period after shutdown
116
What are major components of SBOG Lube Oil system ?
-Lube Oil Reservoir
-Pre/Post Lube Oil Pump
-Main Lube Oil Pump
-Oil regulator assembly/Valve
-Lube Oil Coolers
-Lube Oil Duplex Filter
-Vent with Oil Mist Eliminator
117
Where is the Lube Oil Reservoir at on the Lube Oil System ?
Built within skid or base frame, primary tank rests beneath turbine engine and reduction gearbox
118
What equipment does the Lube Oil Reservoir contain ?
-Level gauge
-Heater to maintain Lube Oil >70F
-Low level switch for an alarm
-Low level switch for engine shutdown
-High pressure switch for an alarm
-Vent line electrostatic precipitator
119
What is the Pre/Post Lube Oil Pump used for in the Lube Oil System ?
-Lubricates Engine and Generator shaft bearings before they’re allows to move
-Circulates Oil for cooling Engine Bearings after shutdown
120
What is Main Lube Oil Pump?
Engine-Driven positive displacement pump mounted on Reduction Drive Gearbox
121
What Oil Regulator Assembly/Valve used for in Lube Oil system ?
-Positioned downstream Main Engine-driven pump
-Used to control oil pressure and temperature within design limits
122
What equipment does the Oil Regulator assembly contain ?
-Pressure Control Valve
-Thermostatic Control Valve
-Ultimate Relief Valve
123
What does Pressure Control Valve do for Lube Oil System ?
Regulates supply pressure to 55psig
124
What does Thermostatic Control Valve do for Lube Oil System ?
Directs/bypass Lube Oil Coolers to maintain supply temp. 120Fahrenheit
125
What does the Ultimate Relief Valve do for the Lube Oil System ?
-Lifts at 100psig and returns oil to reservoir
126
How do the Lube Oil Coolers work ?
-2 air-oil heat exchangers in series mounted on SBOG enclosure
-Electric motor driven fans provide forced air over cooler fins
127
What is the Duplex Filter used for in the Lube Oil system ?
-To prevent contaminants of close-tolerance bearing & meshing gears
-Installed downstream of regulator assembly
128
What is the Selector valve for on the Duplex Filter ? What size are the filters ?
-Valve is at the inlet of filters to select the in-service filters
-10micron filter
129
When will the alarm actuate on the Duplex Filters ?
High D/P alarm will sound at 30psid across filters
130
What is Oil Mist Eliminator used for on the Lube Oil system?(Electrostatic precipitator)
-Installed in lube oil tank vent line, used to recover oil from air/oil vapor escaping reservoir and is returned back to reservoir
131
Why is the oil routed to the Generator bearings pass through another cooling unit ?
Passing through cooling unit to limit temp to 140Fahrenheit
132
How is the Lube Oil that went through engine bearings drained back to the reservoir ? What is being monitored as it’s being drained ?
-It is gravity drained back to reservoir
-Drain Lines are monitored for high bearing temperatures
133
How many radial bearings support engine shaft ?
Has a total of four radial bearings
134
What is the purpose of the Liquid Fuel System ?
To provide right amount of clean fuel to support engine combustion
135
What’re the different phases of operation of fuel system ?
-Provide fuel and atomized air for initial light-off
-Meter fuel for acceleration & operational speed
-Meter fuel to control speeds of engine and support load placed on engine
-Provide for safe shutdown for engine under both normal and emergency conditions
136
What’re the four subsystems for the Fuel System ?
-Fuel Metering system
-Pilot system
-Air Assist system
-Compressor Air system(Pcd)
137
Where are the Fuel Oil Storage tanks located ?
Located at water resources
138
What is the minimum amount of fuel required in a single tank ? What is the level required to be maintained at for the in-service tank ?
-The minimum is 5’ for a single tank
-In-service tank is required to be 9.5’ at least
139
When should CRS be informed to order more fuel for the Fuel Oil Storage tank ?
When level drops below 10’
140
How many Fuel Oil Tanks are in-service ?
Only one tank is in service at a time and other one is maintained empty
141
Why is SBOG full supplied passes through two diesel fuel filters/separator/coalescers?
-Filter removes particulates
-Separator removes water
-Coalescers provide additional filtration layer
142
What is Fuel Metering used for on SBOG ?
Main fuel circuit delivers clean fuel at required pressure and flow to the fuel injectors for the combustion chamber
143
What does the Main Fuel Circuit components consist of ?
-Fuel oil suction strainer
-Fuel Oil Booster pump
-Low pressure duplex filter
-Primary Fuel Oil shutoff valve
-High pressure fuel oil pump
-High pressure filter
-Fuel Oil Control valve
-Secondary Fuel Oil Shutoff valve
-Fuel Injectors
144
What is the Fuel Oil Booster pump used for ? What is it driven by ?
-Ensures high pressure pump downstream has adequate fuel so there’s no cavitation
-it’s driven by AC motor 10gpm @25psig
145
What is Primary Shutoff valve used for on the fuel system ?
-Provides safe shutdown of engine, initiated by an operator or automatic action(opens by pneumatic air)
146
How many fuel injectors does SBOG have ?
Has 12 fuel injectors located around combustion chamber
147
What does the Pilot system do for the SBOG fuel system?
Supplies clean air to pneumatically actuate Fuel Shutoff Valves
148
What happens when solenoid valve is actuated open/closed for the Pneumatically actuated Fuel Shut Off valve is actuated by control system ?
-When Solenoid valve will open allowing pilot pressure to open Fuel Shutoff Valve
-When Solenoid valve closes,pilot pressure will vent and fuel shutoff will close
149
During start up where is Pilot Air supplied from ?
It’s supplied from Air Assist systems Air Reservoir mounted on top of SBOG enclosure
150
What happens to pilot air as engine comes up to speed ?
Pcd air will take over as air supply ,which is filtered by 3micron filter regulated to 90psig
151
What else is operated with Pilot system ?
Reverse Purge Valve
152
What does the Air Assist system do for the SBOG system ?
Provides air to help atomize fuel during engine startup for BOTH torch igniter and each Fuel Injector
153
What is the Air Assist Shutoff Valve used for ? When will it be shut off ?
-Opens on ignition and acceleration sequences
-Valve will shut when engine speed reaches 66%Ngp, at that point will Pcd will take over atomizing fuel
154
What is the Air Assist get supplied from ?
Air Reservoir
155
What is the Air Reservoir maintained at?
Maintained at 85-110psig by DeWalt electric air compressor
156
How is Air Reservoir maintained when SBOG is starting up ?
Diesel Engine will drive an attached air compressor to raise Air Reservoir to 120psig required by Air Assist system
157
What daily checks of the DeWalt air compressor include ?
-Blown down of moisture via Air Tank Drain Valve to prevent corrosion of tank
-Oil dipstick proper oil level
158
What does DeWalt compressor have to protect motor ?
Has thermal overload protector
159
What is the torch circuit used for ?
-Provides air and fuel during ignition sequences
-Air passes through torch supply shutoff valve
-Fuel passes through Liquid Fuel Torch Shutoff Valve
160
What’re the Torch Supply Shutoff Valve & Liquid Fuel Torch Shutoff Valve operated by ?
They’re solenoid valves they’re operated from 24DC control system
161
What’re the components for a single Torch Assembly attached to combustion housing ?
Bottom of engine, consist of torch housing, perforated inner torch tube,igniter plug,fuel& atomizing air supply line, & drain connections
162
What happens to solenoid valves when ignition command is received ?
Solenoid valves will open up sending air and fuel into torch assembly, which is then sprayed into engine air(Pcd)
163
How does Ignitor Exciter & Ignitor plug work ?
-High voltage cables are connected to Ignitor exciter
-Ignitor Exciter send high voltage pulses to Ignitor plug, which sparks and ignites fuel
164
Where will small torch flame flare go into ?
Will flare into combustion chamber igniting fuel mixture of all main fuel injectors
165
When are the Ignition Exciter,Torch Air Assist, and Torch Fuel Supply Valve deactivated ?
They’re deactivated once successful ignition is verified
166
Describe Fuel Injectors on SBOG?
-12 fuel injectors
-Separate fuel & air assist connection
-Swirling vanes designed to help for complete and even combustion
167
What system does Compressor Air system(Pcd) provide air to ?
-Input to Fuel Metering
-Pilot Air system
-Air Assist system
-Turbine Cooling system
-Flameout Module
168
What happens if flameout condition happens and it isn’t detected ?
Will cause large of quantity admitted into combustion chamber, and if not detected could cause uncontrolled re-ignition within engine and Exhaust system
169
What is used to detect Flameout ?
Specific hardware & control logic for detection,such as a Flameout Differential Pressure Switch Monitors engine Pcd
170
What will control system do if a Flameout is detected ?
-Shutdown High Pressure Fuel Pump
-Close Fuel Shutoff Valves to prevent re-ignition
171
What is Fuel System Purging used for ?
Used to remove left over fuel from Fuel System to during engine startup & shutdown to ensure proper operation and combustion
172
What does Fuel System Purging prevent ?
-Injector Coking
-Corrosion from occurring inside engine
173
What is Injector Coking ?
Liquid fuel left dormant in injectors or small supply lines, solidifies due to high Pcd and combustion chamber temp. This will could clog fuel lines
174
What is done to force air flow backwards through Fuel Injectors & Fuel Manifold to purge fuel lines?
On engine startup Reverse Purge Valve is opened to allow Pcd air to flow backwards to remove any fuel or condensate leftover from previous shutdown
175
When will Reverse Purge Valve close ?
Closes at 15%Ngp
176
Why is the Reverse Purge Valve opened during shutdown ?
Allows Pcd to purge fuel lines as engine rolls down
177
Where does 5 gallon Purge Tank collect from ?
-Fuel System Purging
-Fuel Oil Day Tank Vent
-Main Fuel Oil Pump
-Combustion Drain
178
When will combustor drain valve open ?
Will open on engine shutdown when combustor pressure drops 2-5psig to drain away any residual fuel
179
What is Fuel Oil Day Tank used for ?
10 gallon tank used to supply fuel to Starting Diesel Engine
180
Where is Fuel Oil Day Tank supplied from ?
Supplied from upstream of Low Pressure Filter leading to Fuel Oil Booster Pump
181
How is Fuel Oil Day Tank filled?
Isolation valve is opened to fill Tank by differential press. from Fuel Oil Storage Tanks
182
What must Fuel Oil Day Tank Level must be maintained at ?
>70% full and verified nightly
183
What is purpose for SBOG Fire system ?
Detects, indicates, and suppresses fire within SBOG enclosure
184
What does Fire system consist of ?
-Control panel
-Fire warning
-Power Distr. Module
-Fire system control
-Enhanced input/output modules
-Flame detectors
-Gas detectors
-Thermal detectors
-Fire suppression
185
How does Fire Warning system work?
Alerts operators that a fire has been detected or fire suppression has discharged inside the enclosure
186
What is purpose of Red Strobe light and horn on the Fire Warning system?
They are energized 30 seconds PRIOR of CO2 being discharged for fire suppression, to allow workers to evacuate
187
What will happen if high levels of gas are detected ?
-Will alert operator
-will annunciate alarm or initiate a shutdown depending on gas levels
188
How does Ultra violet detectors on the Fire Detection system work for SBOG enclosure ?
-Ultra Violet detectors positioned in certain areas monitoring engine to detect any flame
189
What’re the Infrared Gas Detectors used for on the Fire Detection system for the SBOG enclosure ?
Mounted at enclosure inlet and outlet to detected any flammable vapors entering or leaving enclosure
190
How’re Thermal Detectors used on the Fire Detection system for the SBOG enclosure ?
They’re installed in strategic location to monitor for excess heat or rapid increase temp. indicating a fire
191
How does Fire Suppression Discharge Nozzle work on the Fire Detection system for the SBOG enclosure ?
Nozzles connected to network of piping and the Bottled Fire Suppression Agent, used to flood system during a fire
192
What’s engine shutdown sequence ,when fire,excessive gas,or excessive heat is detected ?
1.)Engine shuts down(Fast Stop Lockout)
2.)Enclosure Ventilation stops
3.)Fire extinguishing agent releases into enclosure
4.) Enclosure dampers close, activated by CO2
5.)After engine stops, control system will interrupt pre/post lube oil pump. AFTER 10minutes it’ll be reenergized to complete lube oil cycle
193
What does the Fire Cylinder cabinet have inside for the CO2 Fire suppression system ?
It houses the primary-release and extended-release CO2 cylinders AND control-head solenoid
194
When are the Primary Release and Extended release systems activated ?
When fire is detected and they activate at the same time
195
How do the primary-release cylinders operate ?
-Primary release control-head solenoid release large amount of CO2into enclosure; .75in Supply Line
-Designed to fully discharge in ONE minute
196
How do the extend-release cylinders operate ?
-Extended-release control-head solenoid valve less amount of CO2 than the primary; .50in supply line
-Maintains CO2 concentration for 20 minutes
197
What is the subsequent release system ?
Redundant fire suppression system that has a 1minute Primary Release and 20minute Extended release
198
When will subsequent release system solenoid valve activated ?
Only activated after Primary Release and Extended Relief control head solenoid valves have been energized
199
What conditions need to be met for the subsequent release system solenoid valve to be activated ?
-Release Confirm Switch inside enclosure hasn’t detected CO2 agent 5 seconds after fire had been detected
-The fire still exists 1 minute after fire was detected
200
What is the two-position Lockout Valve on the Primary Release and Extended Release system used for ?
Used to control path of CO2 discharge, either aligned to enclosure OR vent outside enclosure
201
What must be done to Fire suppression system when entering SBOG enclosure ?
CO2 fire suppression system must be disabled before entering
202
When disabling Fire Suppression system who must you notify?
Must notify Unit 1 control room & Fire Department
203
When will a “CO2 isolation and Enclosure unprotected” alarm ?
Control system monitors position of CO2 Lockout Valves, when either valve is in the TO VENT position it will initiate alarm
204
What is the Auto/Inhibit Key Switch used for on the Fire System control panel ?
Enables and disabled Fire Suppression
205
What will happen if Fire Control panel has Key Switch in Auto ?
System automatically release extinguishing agent when fire is detected
206
What will happen if Fire Control Panel Key Switch is in the Inhibit position ?
Fire Suppression system cannot release extinguishing agent
207
No matter what the key switch position, is what is another way to actuate fire suppression ?
Mechanical handle on fire cabinet can be pulled to release extinguish agent
208
What happen when you take the Key Switch to Inhibit on the Fire Control Panel ?
An alarm will sound when taken to inhibit
209
What functions does SBOG perform ?
-Starts and accelerates engine to operating speed
-Monitors equipment during operation
-Protects engine and driven equip. to be protected from Overspeed, High Engine Temp, Low Lube Oil Pressure
-Controls normal & emergency shutdown
210
What is the Turbotronics control system powered from ?
Operates on 24VDC power
211
What is the Unit Control Panel used for inside the SBOG control room ?
Has all necessary pushbuttons& switches for control input
212
What is Generator Metering Panel used for in the SBOG control room ?
All indications to report operational status
213
What should not be done while SBOG Control Room panels are open ?
Radio should not be used when panels are open
214
What’re the Primary control systems used for ?
Primary control consist of a PLC to provide control,sequencing, and protection functions of SBOG
215
What is back up control system used for ?
Relay based backup used in event of primary control system failure
216
How are backup control relays maintained ?
Maintained in failsafe(energized) condition by a series of relay and switch contacts from backup overspeed monitor,local & remote manual fast stop switches and microprocessor fail relay
217
What happens when any contact in the serious circuit opens ?
Relays are deenergized and backup shutdown sequence initiated
218
What is shutdown sequence?
-De-energizes primary and secondary fuel shutoff valve solenoids to cut off fuel supply
-Driven equip. Unloading devices
-Operates post lube system to protect engine and driven equipment
-Opens Generator circuit breaker
-Backup system active indicator illuminates
219
What happens when resetting Back up control system ?
-Rearms control circuit
-Extinguishes backup system active indicator
-Reset back up overspeed monitor contacts
220
What is the Combination Generator Control Module used for ?
Used to control engine speed and frequency by controlling fuel flow to engine
221
What is control module capable of ?
Maintaining SBOG at rated speed and paralleling SBOG with other generators
222
How is Power Factor control used ?
Used manually by using “voltage increase” & “Voltage Decrease” push buttons
223
What is the Human Machine Interface(HMI) used for ?
Used to display Engine system parameters
224
What does the Operation summary screen display on HMI ?
Shows summary of turbine and generator operating values
225
What does the Process summary screen display on HMI ?
Shows summary of generator power,setpoint values, & generator control modes
226
What does the Engine summary screen display on HMI
Summary of monitored turbine temperatures, turbine operating values, fuel pressure, lube oil temp. & press.,& fuel control operating modes
227
What does the Enclosure summary screen display on HMI
Shows operating values of enclosure temp. , enclosure pressure, and fire suppression system
228
What does the operation sequence screen show on the HMI?
Shows sequence of events for starting and stopping turbine as events occur
229
What does the generator screen show on the HMI?
Shows summary of generator, bus, excitation, control mode, & power operating values
230
What does the Fuel system screen show on the HMI?
Fuel pressure, actuator percentage, and legend to show valves open or closed
231
What does the Start system screen show on the HMI?
Gives operators buttons to start test crank, enable automatic load control for hydraulic starter, bypass load on the hydraulic starter
232
What does the Lube system screen show on the HMI?
-shows line diagram of lube oil system
-provided lube oil pump operating modes
-Lube oil header pressure & temp.
-lube oil filter DP
-Lube oil cooler fan status
-Heater status
233
What does the Engine & Generator Vibration screen show on the HMI?
Shows radial vibration amplitudes
234
What does the Control System Screen show on the HMI?
-Shows selected & active control modes
-Power operating values
-Gas producer speed
-Average T5 temperature
-Percentage that main fuel valve is opened
235
What does the engine details screen show on the HMI?
-Unique turbine info
-Turbine operating temp & pressures
-Timers
-Discharge pressure of Gas Producers Compressor
236
What does the Engine Temperature Screen display on the HMI?
-Shows temp reading for engine thermocouples
-T5 average
-T5 radial plot
-T5 Bar Plot
-T5 Delta Bar Plot
-Number of T5 thermocouples
237
What does the Liquid Fuel Details screen display ?
Summary of liquid fuel systems operating values
238
What does Lube Details screen display on HMI ?
-Shows lube oil system temperatures, -pressures
-status indications
-timer status
-pump operating modes
239
How does the power source for the Control System power work ?
-Consists of AC power source powering battery charger, and battery in cabinet with circuit breakers
240
What does the battery charger do for the control system power ?
Battery charger powers control system and maintains battery charged when AC power IS AVAILABLE
241
What happens when (NHN-M73)AC power is LOST going to battery charger ?
Battery will power Backup control system up to one hour when AC power is NOT AVAILABLE
242
What is the SBOG power flow path ?
-SBOG output power is aligned to NAN-S07, which the can be directed to any 3 units
-SBOG 13.8kv power taps in between NAN-S03 and ESF transformer
243
What powers the SBOGS auxiliaries ?
Local MCC; NHN-M73
244
What does NHN-M73 provide power to at SBOG?
-Enclosure vent fans
-Lube oil Cooler fans
-Lube Oil Heaters
- Air Assist Space Heaters
-Control Room Air Conditioner
-Two 120VAC D-Panels
NHN-D73A
NHN-D73B
245
What is NHN-M73 powered from ?
Powered from Static Transfer switch NHN-U5607 which selects normal or emergency power supply
246
What is normal and emergency power supply for NHN-M73?
Normal supply :NHN-M56
Emergency supply: NAN-S07
247
What kind of Static switch is used ?
Normal seeking switch
248
What happens if static switch is selected to emergency supply, but normal power supply comes back ?
Static switch will switch back to normal supply if it is available more than 30 seconds
249
What are the light indications used for on the static transfer switch ? What is Push button used for on the static transfer switch ?
Green light :normal power supply
Red Light:Emergency power supply
Pushbutton: Used to force a transfer from one power to supply to the other
250
What does D- Panel, NHN-D73A, supply power to ?
-Supplies power to TWO 24VDC battery chargers associated with each SBOG
-Smaller SBOG auxiliaries
251
What does D-Panel, NHN-D73B, supply power to ?
Supplied power to SBOG Control Room Auxiliaries
252
Why does each SBOG have two sets of 24VDC battery chargers & battery ?
One set dedicated to SBOG control system
Second set is dedicated to Diesel Starting engine
253
What does the yellow light mean on the batter charger ?
Means it’s High Rate Charging
254
When will battery alarm reset ?
Won’t reset until High Rate Charge condition is cleared, which mean battery is charged(7 hours)
255
How does NAN-S07 switchgear receive its control power ?
125VDC battery charger supplies D-panel. Then power is supplied to battery and distributed as control power
256
When would SBOG be paralleled with offsite power ?
Usually done for testing purposes
257
What island/utility switch ?
Island mode- Sets SBOG in isochronous and only used during station blackout
Utility mode-Sets SBOG speed control system to droop and used when paralleling with offsite power
258
What happens if voltage difference is to big when paralleling two power sources ?
Arc will trip open breaker on an over current breaker
259
What is syncroscope used for ?
-Analogue meter to display difference in phase angle when paralleling two power sources
-The greater the difference the faster needle will rotate
260
Which way do you want the synchroscope to spin when paralleling SBOG with offsite power?
Rotate slowly in the Fast direction, this is to prevent reverse powering and to allow SBOG to pick up load
261
What does the synchronizing relay do ?
Protects generator output breaker from being closed when two power sources are out of phase
262
What’re the two lights next to synchroscope used for ?
Indications whether two power sources are in phase
In-Phase- light will be out
Out of phase - light will be bright
263
Island mode:Real Power, Reactive power
-Real power, reactive power, and power factor are all functions of loads connected to bus
-changing frequency set point of generator, while in island mode, will adjust speed of SBOG
-Changing voltage set point of generator, while in island mode, will adjust Bus Voltage
264
What will happen when changing frequency set points whil in utility mode?
Will adjust real load being carried by SBOG
265
What will happen when changing voltage set point of SBOG, while in Utility mode ?
Reactive load(KVAR) being carried by SBOG
266
What is the power factor ?
Ratio between kilowatts and kilovolts amps that is drawn from electrical loads
267
What’re the power factor is displayed on an analogue meter with markings ?
.5 lagging, 1.0unity, .5leading
268
What is island mode power factor determined by ?
Determined by connecting loads
269
How is power factor adjusted while in utility mode connected to offsite power ? What should it be maintained in ?
-Power factor controlled by controlling voltage of generator
- Should be maintained between .85-.9lagging
270
What is power factor controlled by when SBOG is paralleled with unit DG ?
Power factor is controlled by the Main Control Room operator by adjusting DG voltage
271
Why must SBOG be aligned to NAN-S07 switchgear within 15 minutes ?
-During a unit blackout to support coping loads
-During loss of power to the SBOG Control Equipment
Necessary because SBOG batteries qualified for one hour, aligning SBOG to NAN-S07 will ensure that SBOG will support a unit that may experience a blackout
272
What must happen within 15 minutes of ready to load light is illuminated ?
SBOG enclosure fan must be running or SBOG will trip
273
What’re the enclosure fans powered from ?
NHN-M73
274
How do you verify that the enclosure fans are running ?
Uses sensing point which detects voltage supply from NHN -M73 to the 24VDC battery chargers, if charging voltage is sensed then it means enclosure fans are running
275
What’re the two events that 15 minute rule is of concern ?
When there is an actual loss of power to NHN-M73(blackout affecting unit 1 or loss of power to NHN-M56)
276
What is sequence of operation when NHN-M73?
1.)SBOG starts within one hour
2.)output breaker will be closed within 15 minutes of its “ready to load”
3.)Static transfer switch to automatically transfer to emerg. Supply (NAN-S07)
4.) supply power to NHN-M73
277
Why must synchroscope must be turned on when closing breaker even on a dead bus ?
Due to an interlock between the two
278
Why must you reclose battery charger AC supply breakers on NHN-D73A within 15 mins of SBOGS “ready to load” light coming on ?
SBOG will trip
279
What is Normal Shutdown Sequence following emergency situation ?
1.)Another source of power is paralleled with SBOG
2.)The SBOG operator will then open the SBOG output breaker
3.)SBOG operator records operating data prior to Engine Shutdown
4.) The SBOG operator presses the “stop” push button
280
When happens after you push stop Pushbutton I’m the shutdown sequence after a emergency situation ?
-SBOG goes into 3 minute cool down mode indicated by the cooldown light on the SBOG control panel
281
The end of cooldown period SBOG will begin to slow down when it reaches 90% what happens to indication light?
-SBOG running light goes out
-Stopping light goes on
282
When does pre lube oil pump start when SBOG is shutdown following emergency condition ?
66% speed starts to lubricate and cool bearings for next 55 minutes
283
When will enclosure ventilation fans stop ?
Will continue to run until Enclosure temp reaches securing set point
