MGM

Question 1

State advantages of using H2

Answer 1

High specific heat capacity
Low Density
Low cost
Non-corrosive
non-conductive

Question 2

State how H2 is cooled in the Generator

Answer 2

Fans mounted to the rotor provide motive force for the H2 and passes over the stators and Rotors to the coolers, the coolers are cooled by SCCW

Question 3

State the basic operation of the core monitor

Answer 3

monitors the particulate contamination of the H2 caused by insulation or paint breakdown due to an overheating condition
Placed in service at 1800 RPM due to fans on rotor causing flow

Question 4

State when bus duct heating auto starts

Answer 4

MGB open (all phases)
OR
breaker 11 and 12 open (all phases)
trips on loss of flow or any of the above breaker shuts

Question 5

State when cooling water flow for bus duct cooling starts

Answer 5

Initiated at 130F to inservice HX

alarms at 190F

Question 6

State when loss of Isophase Bus duck cooling causes a turbine setback

Answer 6

A loss of both Isophase Bus duct cooling fans
after a 30min delay
turbine setback to 55% at 2%/min

Question 7

State relationship between H2 pressure and generator load

Answer 7

As load increases H2 pressure must increase to increase heat removal capability

Question 8

State how H2 is changed in the generator

Answer 8

H2 is vented out the top and CO2 is admitted through the bottom.
In reverse CO2 gets vented out the bottom and H2 gets admitted through the top