Generator Hydrogen and CO2 Flashcards
Why was hydrogen gas chosen as a cooling medium for generator?
it has a high thermal conductivity and because of its small size it provides low friction between the gas and moving parts of the generator
what do we use the carbon dioxide for?
purging oxygen and hydrogen
how do we determine how much hydrogen or carbon dioxide is in the generator?
Gas analyzer
Flow path of hydrogen in the generator?
1) flows between rotor and stator and thru the rotor body
2) internal components of the main gen excitation system
3)hydrogen cooled by cooler with TC and then circulated thru the gas dryer
4) a portion of flow passes thru core monitor and pyrolysate collector to monitor the generator for overheating
what are the general steps in establishing a hydrogen/air atmosphere in the generator?
purge air with CO2 and purge CO2 with Hydrogen
purge hydrogen with C02 and then air
Where is the CO2 distribution tube located in the generator?
bottom of the generator
Where is the hydrogen distribution tube located in the generator and what else can it be used for?
Top of the generator
can be the exit point for hydrogen, C02 or air depending on the purge operation
Where are purge operations controlled from
hydrogen purge station in the turbine 140’
What system supplies the purging air?
Service air
What cooling water is used for hydrogen cooler?
TC
Where is the hydrogen cooler located?
top of the generator
how do we prevent cross connecting the hydrogen and C02?
spool piece
What is the generator hydrogen pressure regulated at?
75 psig
What is the purpose of the dryer moisture remover and where is it located?
to help prevent damage to the generator system from corrosion due to moisture
located above the 140’ east turbine building
how does the dryer moisture remover perform its function?
activated alumina