WHY CONDENSERWHY CONDENSER

What is condensateWhat is condensate

The steam after condensing in The steam after condensing in the condenser known as the condenser known as condensate, is extracted out condensate, is extracted out of the condenser hot well by of the condenser hot well by condensate pump and taken condensate pump and taken to the deaerator through to the deaerator through ejectors, gland steam cooler ejectors, gland steam cooler and series of LP heaters.and series of LP heaters.

Condensate system

• Condensate Extraction Pump : To pump out the condensate to D/A through ejectors, GSC and LPH

• Gland Steam Condenser : To increase the temperature of condensate.

• Condensate polishing unit : To remove cat-ion and an-ion from the condensate.

CEP

• Converts last stage steam of LPT to water

CONDENSER

CEP

GSC

CONDENSER

CPU DEAREATOR LEVEL CONTROL

Minimum recirculation to condenser

Condensate PumpsCondensate Pumps

The function of these pumps is The function of these pumps is to pumps out the condensate to to pumps out the condensate to the deaerator thru' ejectors, the deaerator thru' ejectors, gland steam cooler, and L.P. gland steam cooler, and L.P. heaters. These pumps have heaters. These pumps have FIVE stages and since the FIVE stages and since the suction is at a negative suction is at a negative pressure, special arrangements pressure, special arrangements have been made for providing have been made for providing sealing.sealing.

Stages:Stages:

The pressure build up in 5 stages The pressure build up in 5 stages as suction is at negative pressure.as suction is at negative pressure.

Recirculation:Recirculation:

It is done when the de aerator It is done when the de aerator level controller trips in order to level controller trips in order to prevent cavitations.prevent cavitations.

CEP LINE UPCEP LINE UP

Ensure PTW cancelledEnsure PTW cancelled Ensure box upEnsure box up Suction strainer drain/vent closeSuction strainer drain/vent close Open canister ventOpen canister vent Open re-circulation manual v/vOpen re-circulation manual v/v c/v inst. Air v/vc/v inst. Air v/v Seal water chargeSeal water charge Bearing cooling water chargeBearing cooling water charge Bearing oil level normalBearing oil level normal Relief v/v manual v/v openRelief v/v manual v/v open Suction v/v open Suction v/v open Relies EPBRelies EPB

Supply normal Supply normal Hotwell level N low ( > - 250mm)Hotwell level N low ( > - 250mm) SWGR availableSWGR available SWGR not disturbedSWGR not disturbed Thrust brg temp not highThrust brg temp not high Motor brg. Temp not highMotor brg. Temp not high Motor wdg temp not highMotor wdg temp not high R/c v/v open > 40 %R/c v/v open > 40 % Discharge vent open Discharge vent open Discharge v/v close or stand by selected Discharge v/v close or stand by selected

CEP ISOLATIONCEP ISOLATION

EPB pressedEPB pressed Breaker rack outBreaker rack out Is R/c v/v passingIs R/c v/v passing Close suction v/vClose suction v/v By pass relief v/v closeBy pass relief v/v close Close re-circulation v/v Close re-circulation v/v Close canister vent v/vClose canister vent v/v Discharge vent manual v/v closeDischarge vent manual v/v close Close sealing water v/vClose sealing water v/v Close cooling water v/vClose cooling water v/v Crack open strainer vent. Is there any air Crack open strainer vent. Is there any air

sucking?sucking?

To give the required pressure to To give the required pressure to the feed water before entering the feed water before entering into boilerinto boiler

Horizontal barrel type multi Horizontal barrel type multi stage pump. stage pump.

Boiler Feed PumpBoiler Feed Pump

BOILER FEED BOILER FEED PUMPPUMP

NDE BEARING DE BEARING

SOLE PLATE

(BASE PLATE)

FOUNDATION BOLT

KEYSLEEVE

18

BoosterPump

MotorMain Pump

Suction Strainer

S S for Main Pump

Feed WaterFrom D/A

HydraulicCoupling

To HPH. Recirculation to FST

General Arrangement of BFP

Booster Pump

To Ensure a Net Positive Suction Head (NPSH) for

Main Feed Pump

Saves a Costly Main Pump due to any damage from

Cavitation.

Typically a single-stage, centrifugal pump

Recirculation :

To maintain the Continuous flow of feed water when

the valve to Economizer is Closed

Components of BFP

Suction Strainers

To Protect Booster pump and main pump against

Catastrophic failure due to entry of coarse particles

Hydraulic Coupling

Used to Transmit power from motor to pump as per the

Load requirement

Components of BFP

NPSH is an acronym for Net Positive Suction Head. It shows the difference, in any cross section of a generic hydraulic circuit, between the pressure and the liquid vapor pressure in that section.NPSH is an important parameter, to be taken into account when designing a circuit : whenever the liquid pressure drops below the vapor pressure, liquid boiling occurs, and the final effect will be cavitations : vapor bubbles may reduce or stop liquid flow.In pump operation, two aspects of this parameter are called respectively NPSH (a) Net Positive Suction Head (available) and NPSH (r) Net Positive Suction Head (required), where NPSH(a) is computed at pump inlet port, and NPSH(r) is the limit NPSH the pump can withstand without cavitating.

NPSH

Booster PumpBooster Pump

Major damage in BF pump is Major damage in BF pump is from cavitation or vapour from cavitation or vapour bounding.bounding.

Provides positive pressure at Provides positive pressure at the pump suction.the pump suction.

BFP CARTRIDGE

BFP WITH COMMON FOUNDATION FRAME

BFP SEAL COOLER PIPING

MECHANICAL SEAL

• The use of mechanical seal reduces the loses of feed water in the stuffing box to a minimum.

• Working ability of the feed pump increases. • Cooling of stuffing box space should be perfect by the use

of mechanical seal.• Cooling is carried out by the circulation of water between the

stuffing box space and the cooler. Even after stopping the pump stuffing box cooling should be continued as its cooling circuit is different from the seal cooler.

• Coolers are designed to keep the stuffing box space temperature below 800C.

It consists of two highly polished surfaces, one surface connected to the Shaft and the other to the stationary part of the Pump.

• Both the surfaces are of dissimilar materials held in continuous contact by a spring.

• These wearing surfaces are perpendicular to the axis of Shaft.• A thin film of working fluid between these faces provides cooling &

lubrication.

MECHANICAL SEAL

SEAL HOUSING It houses the Mechanical Seal.

• They give radial positioning to the rotor.• They are of two types :• Antifriction Bearings• Sleeve Bearings

Line Bearings

They locate the rotor axially & take residual axial thrust.

• They are fitted in the NDE Bearing Housing.• They have 8 white metal lined tilting pads held in a

split Carrier Ring positioned on each side of the Thrust Collar.

Thrust Bearings

• They house Journal Bearing at the DE side and both Journal & Thrust Bearings at the NDE side.

• These are in the form of cylindrical castings split on the horizontal Shaft axis, located one each at DE & NDE sides of the Pump.

BEARING HOUSINGS

It houses the hydraulic components of Pumps.• It prevents the leakage and guides the liquid in a

proper direction.• It is closed by Suction Guide at it’s suction side and

Discharge Cover at it’s discharge side.

PUMP CASING

• It guides the fluid from suction pipe to the eye of the Impeller.

• It closes the drive end of Pump Casing and forms the suction annulus.

SUCTION GUIDE

It closes the NDE of Pump Casing and forms the balance chamber.

• It is closed by NDE Water Jacket and Mechanical Seal Housing.

• A Spring Disc is located between the last stage Diffuser and the Discharge Cover Balance Drum Bush.

DISCHARGE COVER

It rotates the mass of fluid with the peripheral speed of its vane tips, thereby determining the head developed or the Pump working pressure.

IMPELLER

IMPELLER

• It converts Kinetic energy of the fluid into Pressure Energy.

DIFFUSER

• It consists of Shaft, Impellers, Balance Drum, Thrust Collar, rotating parts of Mechanical Seals and the Pump Half Coupling.

• It is dynamically balanced.

ROTATING ASSEMBLY

Balancing Device

• A small portion of the feed water in the order of about 10% which is not calculated to the guaranteed delivery capacity is taken off from the space behind the last impeller for the operation of the automatic balancing device to balance the hydraulic axial thrust of the pump rotor.

• The purpose of the balancing device is to take up thrust pressure in a similar way as the thrust bearing.

BALANCE DRUM

The Balancing Chamber is connected either to The Balancing Chamber is connected either to the Pump suction or to the Deaerator, thus the the Pump suction or to the Deaerator, thus the back pressure in Balancing Chamber is back pressure in Balancing Chamber is slightly higher than the suction pressure.slightly higher than the suction pressure.

95% of axial thrust is balanced by the 95% of axial thrust is balanced by the Balancing Drum.Balancing Drum.

Residual axial thrust is taken by Thrust Residual axial thrust is taken by Thrust Bearing.Bearing.

Provision of Thrust Bearing is recommended Provision of Thrust Bearing is recommended for varying condition of Head and Flow which for varying condition of Head and Flow which affect the axial thrust.affect the axial thrust.

BALANCE DRUM

MDBFP LINE UPMDBFP LINE UP

OIL SIDEOIL SIDE

1.1. HC oil level normalHC oil level normal

2.2. Cooler line upCooler line up

3.3. Start AOPStart AOP

4.4. Lube oil WO pr. OkLube oil WO pr. Ok

5.5. Bearing oil flow normal Bearing oil flow normal

6.6. No oil leakageNo oil leakage

Suction v/v open fullySuction v/v open fully R/c v/v manual v/v open R/c v/v manual v/v open R/c v/v c/v inst. Air v/v open*R/c v/v c/v inst. Air v/v open* Motor wdg cooling water supply/ return line v/v openMotor wdg cooling water supply/ return line v/v open Cooling water header pressure okCooling water header pressure ok Main p/p and booster pump mechanical seal water / Main p/p and booster pump mechanical seal water /

cooling water charge cooling water charge Venting done*Venting done* EPB released EPB released Discharge v/v close and IBV closeDischarge v/v close and IBV close Header drain /recirculation/casing drain close * Header drain /recirculation/casing drain close *

TDBFP LINE UPTDBFP LINE UP

OIL SIDE OIL SIDE FEED WATER SIDE FEED WATER SIDE GLAND SEAL STEAM/ VACUUM GLAND SEAL STEAM/ VACUUM

SIDESIDE EXTRACTION STEAM SIDEEXTRACTION STEAM SIDE BARRING SIDEBARRING SIDE

TDBFP LINE UPTDBFP LINE UP

PTW CANCELLEDPTW CANCELLED BOXED UPBOXED UP OIL SIDEOIL SIDE1.1. LOTLOT level normal level normal2.2. CCooler line up from oil /water sideooler line up from oil /water side3.3. AOP/EOP/JOPAOP/EOP/JOP suction/discharge v/v open suction/discharge v/v open 4.4. Governing oil manual v/v openGoverning oil manual v/v open5.5. All lops supply normalAll lops supply normal6.6. Start EOP and check oil lkg.Start EOP and check oil lkg.7.7. Start JOP and check oil lkgStart JOP and check oil lkg8.8. Pump/turbine freeness checking, observe RPMPump/turbine freeness checking, observe RPM9.9. Stop barring engage/disengage main p/p and do Stop barring engage/disengage main p/p and do

FW chargingFW charging10.10. Vapour extraction fan i/sVapour extraction fan i/s

FWFW charging charging

1.1. Open Open BP/BFP/suction strainer BP/BFP/suction strainer ventvent2.2. Charge mechanical seal water BP/BFPCharge mechanical seal water BP/BFP

3.3. Charge jacket cooling wtr and one set of Charge jacket cooling wtr and one set of coolercooler

4.4. Crack open suction v/v *Crack open suction v/v *

5.5. Taking on barring along with Taking on barring along with FWFW charging?charging?

6.6. Close all drain /ventsClose all drain /vents

Gland seal steam /vacuum sideGland seal steam /vacuum side1.1. Open aux stm. drain at 8.5 M then crack Open aux stm. drain at 8.5 M then crack

chargecharge2.2. Open seal steam /aux c/v drain and crack Open seal steam /aux c/v drain and crack

charge 8.5 m iso. v/v charge 8.5 m iso. v/v 3.3. Charge seal stm / leak off stm sideCharge seal stm / leak off stm side4.4. Open turbine drains to flash tank to take Open turbine drains to flash tank to take

vacuumvacuum5.5. Crack open exhst. block v/v and close ,try Crack open exhst. block v/v and close ,try

againagain Extraction stem sideExtraction stem side1.1. Open drain/vent before ESVOpen drain/vent before ESV2.2. Open manual v/v Open manual v/v 3.3. Open mot. v/vOpen mot. v/v