FWH Vent and Drain

Question 1

What is the flowpaths for the feedwater heater drains??

Answer 1

A. Feedwater heater drains cascade
1. 6 > 5 > 4 > 3 > 2 > Drain Cooler > Condenser
2. 1 Drains straight to condenser via Loop Seal.

Question 2

What happens when high heater levels are present?

Answer 2

Reduction in cycle efficiency and possibly back up into the MC.

Question 3

What happens when low heater levels are present?

Answer 3

Reduction in subcooling and could cause flashing and can damage heater.

Question 4

What happens when #1or #2 FWH get a high level?*

Answer 4

• After a 10 sec TD, condensate inlet and outlet valves for train will close.
• Drain from #3 FWH will close.
  (Prevents a potential condensate tube leak from flooding the main turbine).

Question 5

Which FWH’s have a bleeder trip valve?

Answer 5

• 3 - LP
• 4 - LP
• 6 - HP
• SSE - LP

Question 6

How do the valves respond to a loss of air?

Answer 6

• Dump Valve: Open
• Level Control Valve: Closed
• Vents: Closed

Question 7

What is the interlock associated with the condensate inlet/outlet (1613/1600) valves??

Answer 7

If either the condensate inlet (HV-1613 A, B, C) or outlet (HV-1600 A, B, C) in the respective train is not 100% open, FWHTR 6 (A, B, C) level control valve closes.

Question 8

What occurs on a Hi FWH level?

Answer 8

Dump valves open and upstream drain valve closes.