Steam/Water Flashcards
(34 cards)
What is the delay time prior to a low drum level trip
One minute delay timer
Does the feedwater ESP block valve close during boiler trips
It only close when boiler has been ESPed or if valve is in manually activated at ESP panel
What is the purpose of the feed water area isolating valve and when is it used
The feed water isolating valve isolates the boiler drain system from the mud drum blowdown tank
It is used whenever the boiler is hydroed, filled, or isolated for a major outage.
In what order will safty valves operate
Superheater first followed by the steam drum vents
What devices protect the boiler from over pressure
Superheater and steam drum saftey valves
What is the #2 recovery design pressure
700 psi
How many trs violations does the state allow
Zero
How many TRS excursions does the state allow
Two (2) excursions per calendar quarter
What is the differance between a TRS excursion and a violation
Excursion - TRS 12hr average finishes above permit
Violation - when the 3rd excursion occurs within a calendar quarter
What can happen if the steam trap is not operating correctly
Stuck closed - condensate can fill the header leading to possible smelt water reaction inside the furnace
Stuck open - steam is continually wasted, High cost
What is included in the sootblower system that purges the water from the steam supply
Steam trap is mounted at the bottom of each sootblower steam supply header
How is the ID fan steam lance operated
Steam lance is operated one minute of every 20 minutes
Local timer
What does the ID fan steam lance do
Cleans the buildups from the ID fan rotor
How is the ID fan driven
Fan is driven by a 3200 hp steam Turbine using 600 psi
Steam exhausting to 50 psi
What is the centerline for O2 on the boiler
1.5 - 2.5
2 is the target
What is the differance between operating sootblowers in modicon mode versus computer mode
Modicon - blow in numerical order
Computer - by recipe ( normal)
If the secondary windbox pressure needs to be raised or lowered, how should it be done
Change the splits (%)
Or
Increase the total air
What happens if the air flow is allowed to get too low while burning oil or liquor
Boiler will trip on low air flow
Will flame out
Describe the procedures for putting the steam coil air heater(SCAH) in and out of service
….
What is normal economizer exit flue gas temperature
675 - 650 (IN)
400 (out)
Why not operate the furnace draft higher or lower than target
Low - trip ID fan out on speed
High - cause boiler to blow back
What is target for furnace draft
- 0.3
Where is the furnace draft reading taken
Furnace draft tap is located in the upper furnace on the north boiler wall opposite the screen and sends its signal to TDC group 1
How is furnace draft controlled
- 0.3
Controls ID fan speed
