Main and Auxiliary Condensate System

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Main and Auxiliary Condensate System

• 62B - 214

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OVERVIEW

• Major components
• Pump submergence control
• Operation of Main Air Ejectors
• Inter-relationships with input and output
  branches
• Mn v. Aux Condensate System
• Steam side Lay-ups

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SYSTEM FLOW

• Steam condenses in Main Condenser
• Condensate collects in hotwell

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Show transparencyCROSS-SECTIONAL VIEW OF MAIN
CONDENSER
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SYSTEM FLOW

• Hotwell to MCP suction
• Pump discharge to Mn Air Ejector Cndsr

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Components

• Pumps
• 2 or 3 stage vertical, centrifugal,
• non-positive displacement
• Motor or Turbine driven
• Vented to Main Condenser

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Main Condensate Pump
Discharge passage
Second stagesuction
Suction from hotwell
First stage discharge passage

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Terminology

• Net Positive Suction Head
• Total amount of pressure on the suction side of a
  pump
• Cavitation
• Formation and collapse of gas bubbles within a
  pump impeller
• Flow Rate
• Gallons per minute flowing from the pump

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Submergence Control

• Characteristic of centrifugal pumps that assists
  in maintaining hotwell level and flow through the
  pump by the interaction of the physics of NPSH
  (height and weight of water) and cavitation.
• Applied to non-throttled system.

No operator action is required.
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Components

• Thermometers
• Key locations (hotwell, To/From Main Air
  Ejector)
• Remote viewing
• Salinity Indicators
• Indicate potential system contamination
• Verified by chemical test
• Removable (for cleaning)

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SYSTEM FLOW

• Circulation of Condensate in Mn Air Ejector
  Condenser (Cooling Medium)
• Air Ejector outlet branch to recirc valves

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Main Air Ejector

• Creator of initial vacuum inside Main
• Condenser
• Nozzles (Similar to another non-positive
• displacement jet pump EDUCTOR)

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Show transparencyAIR EJECTOR NOZZLE
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(No Transcript)
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Show transparencyFLOW DIAGRAM OF AIR EJECTOR
CONDENSER
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Components

• Air Ejectors and Air Ejector Condenser
• 150 PSI Steam flow to A.E. nozzles
• Draws air and non-condensable gases from
• Main Condenser
• Shell and tube heat exchanger
• Cooling medium is fresh water (i.e. Main
• Condensate)

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Components

• Recircs
• Manual or Thermostatic control
• Opening affects hotwell level thereby
• affecting...
• Rate of flow through the Air Ejector
• Condenser (i.e. discharge temp 140-160 deg F)

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140-160 deg F

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SYSTEM FLOW

• Condensate discharge valve to DFT
• operational requirements ?
• Condensate inlet valve to DFT

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MFBPs
HI
RECIRCS
LOW
VENT
GLAND
MEAJ
SEAL

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MISCELLANEOUS BRANCHES

• Provides cooling to the SW Heater in Distilling
  Plants
• Receives in puts from the Auxiliary Condensate
  sysytem.
• Receives drains from the Distilling Plant SW
  Heater.

• Condensate and Main Feed Pump gland cooling.
• Chemical Injection Tank.
• Makeup Feed and Excess Controls.
• Backfill from the DFT.

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EXCESS FEED
RUN DOWN
AUX CONDs
FWDCT
MFBPs
AUX COND
HI
MFP GLAND SEAL
RECIRCS
LOW
MUF
FWDCT
CHEM INJ TNK
140-160 deg F
EVAP FD HTR DRAINS
VENT
GLAND
MEAJ
SEAL
SALINITY CELL

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Interrelationships

• Condensing steam assists Air Ejector to maintain
  vacuum.
• Condensate level affects vacuum if allowed to
  accumulate in the Main Condenser.
• Rapid changes in condensate flow to the DFT can
  Quench and Flash a hot DFT. This can severely
  damage the DFT or create a LMFC casualty.
• Circulation of condensate cools the Main Air
  Ejector Condenser.
• Acts as a receiver/source for other systems.

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Auxiliary Condensate System
EXCESS FEED
FWDCT
Main Condenser
MFBP
OTHER SSTGs
HI
RECIRC
MFPs
LOW
MUF
CHEM INJ TNK
FWDCT
AUX AIR EJECTOR
EVAPs
VENT
GLAND
SEAL
AUX COND PMP
MN COND

SALINITY CELL
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MAIN CONDENSER STEAM SIDE LAYUPS
Less Than One Month
Drain the hotwell and keep dry
Excess of One Month
Drain out ASAP. Dry using heated air. Blower
discharge in hotwell. Vent through turbine
exhaust casing. After complete, seal and check
weekly. Repeat if necessary.
See NSTM Chapter 254
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Questions?
break time
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Main and Auxiliary Condensate System

• 62B - 214