Lesson 06 - Feed & Condensate

8/8/2019 Lesson 06 - Feed & Condensate

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BoilersBoilers

BOILER TRAININGBOILER TRAININGEng: Hafez YakoutEng: Hafez Yakout



Main Condensate and Feed SystemsMain Condensate and Feed Systems

BOILER TRAININGBOILER TRAINING

Eng: Hafez YakoutEng: Hafez Yakout



ObjectivesObjectives Purpose of Condensate and Feed Systems Purpose of Condensate and Feed Systems

and key component functionsand key component functions

Principles of operation and key Principles of operation and key

components of the automatic boiler control components of the automatic boiler control

systemssystems



M ain Condensate System Purpose M ain Condensate System Purpose

Condense steam to water Condense steam to water Pump condensate from main condenser Pump condensate from main condenser

to DFT to DFT

Provide cooling for air ejector condenser Provide cooling for air ejector condenser



Condensate System ComponentsCondensate System Components

Main Condenser Main Condenser HotwellHotwell

Main Circulating Water System Main Circulating Water System Main Condensate Pump Main Condensate Pump

Air Ejectors Air Ejectors



Condenser M U FeedTank

Condensate

PumpAir Ejector

Condenser

CONDENSATION



M ain Condenser

M ain Condenser

Operates at a vacuum to lower theOperates at a vacuum to lower the

condensation temperature whichcondensation temperature which

increases plant efficiencyincreases plant efficiency

Prevents condensation of steam in the Prevents condensation of steam in the

turbineturbine

Typically a SINGLE PASS, CROSS Typically a SINGLE PASS, CROSS

FLOW, INDIRECT CONTACT FLOW, INDIRECT CONTACT

H otwell H otwell -- -- Stores condensateStores condensate









M ain Condensate Pump M ain Condensate Pump

H otwell to DFT H otwell to DFT

TypeType

± ± Normally electric driven. Normally electric driven.

± ± Non Non--positive displacement positive displacement

Located below hotwell to provide sufficient Located below hotwell to provide sufficient

NPS H TO PREVENT CAVITATION!!! NPS H TO PREVENT CAVITATION!!!



Air Ejectors Air Ejectors Remove non Remove non--condensable gases fromcondensable gases from

condenser condenser

Two stagesTwo stages

Warms condensateWarms condensate

Draws initial vacuum on the Main Cond. Draws initial vacuum on the Main Cond.

Steam activated jet pumpsSteam activated jet pumps





M ain Feed System Purpose

M ain Feed System Purpose

Deaerate Deaerate

Preheat Preheat

Store/Transport water from DFT to boiler Store/Transport water from DFT to boiler



M ain Feed System Components M ain Feed System Components

Deaerating feed tank (DFT) Deaerating feed tank (DFT)

M ain Feed Boost Pump M ain Feed Boost Pump

M ain Feed Pump M ain Feed Pump

Feedwater Control ValveFeedwater Control Valve

Economizer Economizer



DFT

B t r

P u m p

F

Pump

FEED (DFT, MFBP, MFP)



Deaerating Feed Tank (DFT) Deaerating Feed Tank (DFT)

Preheats feedwater Preheats feedwater

Deaerates feedwater Deaerates feedwater

Stores feedwater Stores feedwater





Deaeration

STORAGE

SECTION

EAERATING

SECTION



Deaeration

STORAGE

SECTION

TRAYS



Deaeration

STORAGE

SECTION

St m

Inlet



Deaeration

STORAGE

SECTION

Condensate

Retur n

Steam



Deaeration

STORAGE

SECTION

Vent

Condensate

Retur n

Steam

To eed Water Pumps



Main Feed Boost Pump ( Main Feed Boost Pump ( M

FBP) M

FBP) Ensure there is always sufficient NPS H for Ensure there is always sufficient NPS H for

the MFP, preventing vapor lock the MFP, preventing vapor lock

(Typically a single(Typically a single--stage, double stage, double--suction, suction,

centrifugal pump)centrifugal pump)

Electric Motor Electric Motor



M AIN FEED PU

M P (

M FP)

M AIN FEED PU

M P (

M FP)

Provides water to the boilers at a Provides water to the boilers at a

sufficient rate and pressure to ensure sufficient rate and pressure to ensure

boiler level is maintained boiler level is maintained

Typically: Multistage, highTypically: Multistage, high--speed, speed,

centrifugal pump. May be either steamcentrifugal pump. May be either steamor electric drivenor electric driven

Discharge pressure up to Discharge pressure up to 13001300 psig psig



Feedwater Control Valve (FRV)Feedwater Control Valve (FRV)

Maintains boiler water level in Maintains boiler water level in

steam drum steam drum Normally controlled by Automatic Normally controlled by Automatic

Boiler Control System Boiler Control System

± ± Air controlled valveAir controlled valve



ECONOM

IZER ECONOM

IZER

U ses the exhaust of the boilersU ses the exhaust of the boilers

to preheat the incoming water to preheat the incoming water Increases temperature by Increases temperature by

approximately 140F approximately 140F



MAKE

MAKE--UP/EXCESSUP/EXCESSFEED SYSTEMFEED SYSTEM





AUTOMATIC BOILERAUTOMATIC BOILERCONTROL SYSTEMSCONTROL SYSTEMS



Automatic Boiler Control Systems Automatic Boiler Control Systems

Automatic Combustion Control (ACC) Automatic Combustion Control (ACC)

±± Maintains boiler¶s steam drum pressure by Maintains boiler¶s steam drum pressure by

controlling rate of combustion (air/fuel)controlling rate of combustion (air/fuel) Feedwater Control System (FCS)Feedwater Control System (FCS)

±± Regulates flow of feedwater to boiler toRegulates flow of feedwater to boiler to

maintain levelmaintain level Diff Control System of MFP (DCS)Diff Control System of MFP (DCS)

±± Maintains feedwater supply pressure aboveMaintains feedwater supply pressure abovesteam drum pressuresteam drum pressure



I. I. Automatic Combustion Control Automatic Combustion Control System (ACC) System (ACC)

Purpose: To maintain the boiler steam Purpose: To maintain the boiler steam--

drum pressure at a constant 165bar during drum pressure at a constant 165bar during steady and changing steam conditions steady and changing steam conditions

± ± Measures (steam drum pressure)Measures (steam drum pressure)

± ±

Compares (actual pressure to desired)Compares (actual pressure to desired) ± ± Computes (error signal)Computes (error signal)

± ± Corrects (air and fuel flow to furnace)Corrects (air and fuel flow to furnace)



Automatic CombustionAutomatic Combustion

Control (ACC) SystemControl (ACC) System



II. II. F F eedwater Control Systemeedwater Control System

(FWC)(FWC) Purpose: To regulate the supply of Purpose: To regulate the supply of

feedwater sent to the boiler for use in steam feedwater sent to the boiler for use in steam

production production

± ± Measures (fw flow, steam flow, boiler Measures (fw flow, steam flow, boiler

HH220 level)0 level)

± ± Compares (actual level to desired level)Compares (actual level to desired level)

± ± Computes (error signal)Computes (error signal)

± ± Corrects (feedflow via FRV)Corrects (feedflow via FRV)



Feedwater Control System (FCS)Feedwater Control System (FCS)



III. III. M FP Differential Pressure M FP Differential Pressure

Control SystemControl System

Purpose: Ensures that the feedwater Purpose: Ensures that the feedwater--supply supply

pressure is maintained at a constant value pressure is maintained at a constant value

above the steamabove the steam--drum pressuredrum pressure

Measures (MFP disch press/ Stm drum press)Measures (MFP disch press/ Stm drum press)

± ± Compares (D/P)Compares (D/P)

± ± Computes (error signal)Computes (error signal)

± ± Corrects (alters MFP speed via stm supply)Corrects (alters MFP speed via stm supply)





The End The End

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Lesson 06 - Feed & Condensate