EH Control System Flashcards
1
Q
Purpose of the EH Control System
A
-Regulate the amount of steam admitted to the turbine and to rapidly isolate the turbine in an emergency.
2
Q
GV (Gov Valves) and load
A
- 1&3 open to 15%
- 2&4 open from 15-21%
- All 4 open together from 21-100%
3
Q
EH fluid pumps
location, power supplies, auto start and lockout
A
- Located under EH fluid reservoir
- A powered from MCC-4
- B powered from MCC-3
- Standby pump starts at 1250psig (normal 2000psig)
- Standby pump will lock out on Lo-Lo level in reservoir. (7.625 inches)
4
Q
EH-64
EH System Relief valve
A
- Common to both A/B EH pumps, drains excess oil back to the reservoir
- Set fro 2300psig
- High Pressure alarm is 2200psig
5
Q
EH fluid is cooled by?
A
- 2 Heat exchangers cooled by service water
- operating temperature is 85-140F
6
Q
IA is provided to the system for?
A
-Reduce the moisture content in the EH control System
7
Q
Eh Auxiliary Filter System
made up of?
A
- 1 hp pump, and 2 removable element filters
- 20psig and lowering, pump turns on
- 40psig and rising, pump turns off
- 10psig and lowering pump turns off
8
Q
2 accumulators associated with system
A
- High Pressure Accumulators are back up to the EH pumps and help maintain system pressure. 1250psig pressure charge of N2 gas. (4)
- Low Pressure Accumulators serve as a shock absorber or surge chamber to displace fluid in the drain system during unloading. (16 total)
9
Q
Main Turbine Steam Valve Actuators
4 kinds
A
- Main Turbine Stop Valves
- Turbine Control Valves (Gov Valves)
- Reheat Stop Valves
- Interceptor Valve
10
Q
EH Fluid works with/on the Valves how?
A
-The Valves use high pressure fluid to open and spring action to close.
