Feed & Condensate cycleFeed & Condensate cycle

Performance of Condenser & Performance of Condenser & Feed HeatersFeed Heaters

Pumps & FansPumps & Fans

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Feed & Condensate Feed & Condensate Feed & Condensate Feed & Condensate cyclecycle

Chemical Parameters at Feed / Chemical Parameters at Feed / Condensate CycleCondensate Cycle

Performance Performance Of Of

Condenser Condenser & &

Feed HeatersFeed Heaters

Condenser

• Type Two pass, Single shell• Total tube 15876• Surface area 14,736 m2

• CW flow 28,890 Cu.m/hr• CW flow 28,890 Cu.m/hr• CW temp 330C• Vacuum 76 mm Hg• Tube material ASTM A312 Gr 304 S.S.• Weight 225 Te (dry)

406 Te (working)

Condenser performance Test

Flash Box

Condenser FoulingCondenser Fouling

MechanicalMechanical

ScaleScale

DepositionDeposition

Corrosion productsCorrosion products

MicroMicro--BiologicalBiological

WATERBOX

Conco Bullets used in Condenser cleaning

Steam spaceSteam space

Unit#3 CW Inlet Screen

Cooling water

parametersparameters

Horizontal “U” tube Double pass counter flow Feed Heater

Temperature of heating fluid

Temperature of heated fluid

Length

Δtinlet

Δtoutlet

Liquid ring pumps (Nash)Liquid ring pumps (Nash)

•• The shaft and impeller The shaft and impeller assembly is mounted assembly is mounted eccentrically relative to the eccentrically relative to the pump casing pump casing

•• As the impeller rotates the As the impeller rotates the service liquid ( which is service liquid ( which is continually supplied to the continually supplied to the pump ), is forced outwards by pump ), is forced outwards by centrifugal force to form a centrifugal force to form a liquid ring revolving concentric liquid ring revolving concentric to the pump casing.to the pump casing.

Liquid ring pumps (Nash)Liquid ring pumps (Nash)

•• Because of the eccentric Because of the eccentric position of the impeller, position of the impeller, the liquid ring will move the liquid ring will move towards and away from towards and away from the shaft, resulting in a the shaft, resulting in a the shaft, resulting in a the shaft, resulting in a liquid piston action which liquid piston action which displaces the air or gases displaces the air or gases between the spaces of the between the spaces of the impeller blades impeller blades

Condensate Extraction Pump

• Type Vertical Caisson

• Manufacturer Weir pump Ltd.

• Duty 767 Te/hr

• Speed 1406 rpm• Speed 1406 rpm

• No. of stages 5

• Efficiency 83%

• NPSHA above floor 1.25 m

Boiler Feed Pump – Booster stage

• Type Cent. Hor. single stage• Manufacturer Weir pump Ltd.• Suction temp. 1700C• Suction pressure 8.45 kgf/cm2

• Discharge pressure 18.98 kgf/cm2 • Discharge pressure 18.98 kgf/cm2

• NPSHA above impeller eye 15 m• Flow rate 993.3 Te/Hr• Efficiency 80.5%• Speed 1406 rpm• Leak-off flow 220 m3/hr• Driver rating 8.8 MW

Boiler Feed Pump – Pressure stage

• Type Cent. Hor. 3 stage Barrel• Manufacturer Weir pump Ltd.• Suction temp. 1700C• Suction pressure 18.53 kgf/cm2

• Discharge pressure 200 kgf/cm2 • Discharge pressure 200 kgf/cm2

• NPSHA above impeller eye 126 m• Flow rate 993.3 Te/Hr• Efficiency 80.5%• Speed 5730 rpm (scoop)• Leak-off flow 220 m3/hr• Driver rating 8.8 MW

Fan Performance and efficiency

For centrifugal fans -

Volume Flow

Fan total pressure and shaft power

For Backward curved

For Forward curvedFor Radial

Efficiency

Flow

Volume Flow

Pressure Power Efficiency

Power vs FlowPower vs Flow

Control with outlet damper Control with variable IGV Control with VFD

Stall Condition

The angular relationship between the air flow impinging on the blade of a fan and the blade itself is known as “the angle of attack”.

In axial flow fan, when this angle exceeds a certain limit, the air flow over the blade separates from the surface and centrifugal force then throws the air outwards, towards the rim of blades. This action causes a build up of pressure at the blade tip, and this pressure causes a build up of pressure at the blade tip, and this pressure increases until it can be relieved at the clearance between the tip and the casing.

Under this condition the operation of the fan becomes unstable, vibration sets in and the flow starts to oscillate. The risk of stall increases if a fan is oversized or if the system resistance increase excessively.

Blade operating in ideal conditions

Blade operating in stall

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