Feed Water Heaters Vents And Drains Flashcards
How does the feed water heaters improve overall plant efficiency?
They improve cycle efficiency by capturing latent heat of vaporization of bleed steam.
What are the Heater Drain Pump trips?
Extreme low level in associated heater. Overcurrent / Overload. Turbine trip. Manual. Loss of suction to middle pump only if HMO-564 or HMO-563 are not full open.
What are the Heater Drain Pump start interlocks?
Either HMO-564 or HMO-563 which are the suction valves have to be full open.
What is the affect on the main feed water system with the loss of a Heater Drain Pump?
Lower efficiency and auto start a Hot well pump and condensate buster pump on low suction on the main feed pump.
How do heater drains cascade?
From high to low.
What must exist for heat transfer to occur?
A temperature difference.
What is the purpose of the heater vents?
Remove non-condensable gasses from heater shell side.
Which heaters are high pressure?
U1 5 and 6 U2 4,5 and 6
What are the steam and liquid inputs to the high pressure heaters?
Liquid - High pressure turbine. Drains from next higher heater.
Bleed steam from HPT for Unit 1 #6 heater and Unit 2 5 & 6 heaters.
HPT Exhaust (cross under) supplies steam to Unit 1 5 heaters and Unit 2 4 heaters.
What are the steam and liquid inputs to the low pressure heaters?
Bleed steam from low pressure turbines. Drains from next higher heater.
Where do the low pressure heaters drain and vent to?
Condensers.
How much flow is a heater string bypass good for?
20%.
Where do heater drain pumps take suction?
U1 #5 heaters North “B” South “A” Middle both. U2 #4 heaters North “A” South “B” Middle both.
What happens when you get Hi level alarm on a heater?
The alternate dran opens.
What happens when you get a Hi HI level alarm on a heater?
The steam supply valve goes closed.
