Hydrogen Seal Oil - 1.0 Flashcards
From where does hydrogen seal oil get makup oil? Does it provide any other functions?
From the main turbine lube oil system which also acts as the systems cooling
What happens when the main seal oil pump discharge loses pressure?
The emergency seal oil pump will start at 110 psig
Where and how does the seal oil vacuum pump get its operating oil?
Oil supply solenoid valve opens automatically when the pump is running to supply seal and operating oil.
What are the alternate sources of oil flow through the hydrogen seal oil system?
Main Seal Oil Pump(MSOP) - Normal
Emergency Seal Oil Pump(ESOP) - Abnormal
Main Turbine Lube Oil(MTLO) bearing supply - Emergency
Are there any special considerations when using the ESOP?
DC powered
Extended use will degrade H2 purity in the main generator since flow is from the bearing oil header, not the vacuum tank.
Are there any special considerations when using MTLO for the hydrogen seal oil system?
Requires venting the generator casing to 8psig to ensure proper DP
Can the Recirculation seal oil pump be used to seal H2 in the generator?
No, used to detrain oil.
How does the Seal Oil system keep H2 from escaping the generator?
Hydrogen Seal Oil Pressure is maintained at least 5psig > than H2 pressure (Preferably 8 psig >) to prevent hydrogen from leaking out of the main generator by an automatic valve. Valve controls seal oil pressure and maintains it higher
What is the purpose of the float trap in the H2SO system and are there any precautions for its operation?
Float trap ensures that no H2 leaks from the hydrogen detraining tank over to either the air detraining tank or the vacuum tank. It should be bypassed at low gen pressures (<5 psig) since it does not operate properly at these pressures
What is the most likely cause at Hope Creek of seal oil contamination?
A failure of the float trap or extended operation with little or no gas pressure in the generator would cause level to rise due to a backup of oil from the H2 seal oil drains and if the problem was not resolved it would require the turbine to be tripped. A high level alarm will precede any oil entry into the generator under these conditions.
What is the minimum H2 pressure that the Main Turbine can be operated?
30 psig
Must trip turbine and lock out the generator
If power is >18%, then you must also reduce recirc to minimum and lock the the mode switch in shutdown
