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HEATTRANSFER

PRODUCTS

FEEDWATER

HEATERS

STEAM

SURFACE

CONDENSERS

DEAERATORS S.p.A.

POWER

AND

INDUSTRIAL

PLANTS

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CERTIFIED QUALITY

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STFhas been involved since many years in the de-

sign and manufacturing of Heat Transfer Products to

be used in the Power Generation field for both utility

and industrial applications.

Such Products include main components of the ther-

mal cycle like Steam Surface Condenser, LP and HP

Feedwater Heater, Deaerator.

STF designs and manufactures those components

according to the criteria outlined in the following sec-

tion that illustrates the main features and advantages

of the STF s standard design.

In addition STF can supply all other Power Plant Heat

Exchangers and Pressure Vessels (like closed cycle

water coolers, steam transformers, flash tanks etc.)

apart of providing all the supplied equipment with themain accessories like vacuum system, tube cleaning

system, safety valves, rupture disks etc.

STF can provide the equipment to meet standards

and codes such as:

g EN 13445

g Italian Codes for Pressure Vessels

gASME/ASTM

g HEIgTEMA

gAD MERKBLATTER

g PD 5500

g CODAP

STF is certified ISO 9001:2008

and holds the Stamps S, ASME U and U2.

S.p.A.HP feedwater heater

for 2 x 880 MW

power plant.

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The STF design criteria, which reliability has been

proven through a successful operating experience,

recognizes the value of conservatively designed,

high-quality equipment capable of withstanding

long-term cyclic operation. To this end, the following

features have been developed to enhance reliability

and availability.

g Independent desuperheating zone closures.

g

Baffle configuration and spacing based on conser-vative mass and linear velocity criteria.

g Fully enclosed self-venting drains sub-cooling zone.

g Liberal sub-cooling zone entrance areas to permit

low approach velocities which prevent flashing of sa-

turated drains.

g Internal, centrally located venting arrangement to

provide positive means of continuously venting con-

densing zone.

g Channel cover configurations for all nozzle layouts.

g Stainless steel impingement plates.g Fully automated tube-to-tubesheet welding pro-

cedures both for channel ride and shell ride (IBW

technique).

g Finite element stress and vibration analysis for all

operating conditions.

g Analysis of a single heater and of a feedwater stre-

am behaviour in all operating conditions.

FEEDWATER HEATERSHorizontal HP feedwater

heater for a 325 MW

unit under shipment.

Vertical head downHP feedwater heater

under shipment.

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LP duplex

feedwater heater

tube bundle.

HP feedwater heater

desuperheating zone

baffle arrangement.

High pressure

feedwater heater bundle

under assembly.

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HP feedwater heater for 2 x 1300 MW power plant

Finite Element Analysisof HP feedwater heater.

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Reformer waste heat boiler

for a hydrogen production unit

before shipment.

Closed cycle water heat

exchanger for a 325 MWpower pant.

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TIE RODSFULL SUPPORT PLATES

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DESUPERHEATING ZONE HEMISPHERICAL HEAD CHANNEL

DRAINS SUB-COOLING ZONE

FEEDWATER INLET

MANWAY

FEEDWATER OUTLETPARTITION ASSEMBLYZONE SHROUD THERMAL SHIELDSSHELL

STAINLESS STEEL IMPINGEMENT PLATE

TUBE SHEET

ZONE ENCLOSUREZONE BAFFLES

ENTRANCE

(SNORKEL)

END PLATE

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STF designs and manufactures steam surface

condensers with superior design integrity and pro-

duct reliability.

A STF condenser stands apart in its field because of

a conservative design philosophy that uses thorou-

ghly field-tested and proven standards for thermal

and mechanical design to provide the client with

units offering superior efficiency and availability.

These standards are continually reviewed and upda-

te according to industry needs, analysis of field servi-

ce problems and design improvements.

Condensers can be preassembled in the workshop

to a high degree in order to reduce on- site construc-

tion costs and erection time.

The tubesheet is the heart of a steam surface conden-

ser and tubesheet design determines overall efficiency.

STF s tubes lay-out is the result of a satisfactory

experience in designing and fabricating high-efficien-

cy condensers for a variety of applications using te-sted and proven conservative standards.

In a steam surface condenser, the proper positio-

ning of the tubes in the tube bundle assures ne-

gligible pressure drop, maximum surface ut ilization,

optimum reheating and deaeration, return of con-

densate to the system at saturation temperature,

and other operational advantages.

STEAM SURFACE CONDENSERS

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STEAM FLOW PATHS ARRANGEMENT

STEAM

INLET

TURBINE CONDENSER

EXHAUST NECK CONNECTION

STEAM FLOW

CENTER STEAM LANE

GAS-VAPOUR PIPING

INTERRUPTER BAFFLES

GAS-VAPOUR COOLER BAFFLES

SIDE STEAM LANE

TUBE SUPPORT PLATE

STEAM CROSSUNDER

(REHEATING AND DEAERATING ZONE)

CONDENSATE STORAGE

CONDENSATE OUTLET

HOTWELL

GAS-VAPOUR ZONE TUBES

SHELL

CONDENSING ZONE TUBES

TUBE SHEET

GAS-VAPOUR OUTLET

EXHAUST NECK

(STEAM DOME)

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VIEW OF STEAM SURFACE CONDENSER

1- FULL PERIPHERAL ENTRY OF STEAM INTO

THE TUBE BUNDLE RESULTS IN LPW STEAM VE-

LOCITIES AND NEGLIGIBLE PRESSURE DROP.

2-EQUAL TUBE BUNDLE PENETRATION PATHS

PROMOTE EFFECTIVE USE OF ALL CONDEN-

SING SURFACES.

3- MINIMUM STEAM-TRAVEL DISTANCES MI-

NIMIZE PRESSURE DROP ACROSS THE TUBE

BUNDLE.

4- A CENTRALLY LOCATED AND ENCLOSED

ZONE WITH GENEROUS HEAT TRANSFER SUR-

FACE EFFECTIVELY COOLS AND REMOVES GAS

VAPOURS FROM THE TUBE BUNDLE.

5- CIRCULATION OF STEAM UNDER AND UP

THROUGH THE BOTTOM OF THE TUBE BUND-

LE PROVIDES FULL REHEAT AND DEAERATION

BY SCRUBBING THE CONDENSATE FALLING TO

THE HOTWELL.5 5 5 5

1

1

1

1

4 4

2

2 2

2

3

3

3

3

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Titanium tubes

welded to titanium

cladded tubesheet.

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TYPICAL SURFACECONDENSER

SIDE STEAM ENTRY

SECTION

STEAM

INLET

VIEW FROM TURBINE

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DEAERATORS

STF designs and supplies deaerators of the spray

and tray type.

The typical STF deaerator consists of two vessels,

placed one on top of the other.

The top vessel consists of the deaerating tower, ver-

tical in small units and horizontal in large units, on top

of it there is the sprayng of the water to be deaerated.

Then the condensate falls by gravity through a series

of trays where it is broken up in many weirs.

The mechanical separation of the water falling from

one tray to the other in conjunction with the thermal

and dynamic action of the steam, rising to the top of

the vessel, assures the removal of the gases dissolved

in the water.

Finally the water is discharged in the storage tank,

which capacity is studied as function of the plant

needs.

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Deaerator

Internal view

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HP feedwater heater for a 2 x 1300 MW nuclear power plant

LP heater for 2 x 880 MW nuclear power plant

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NUCLEAR COMPONENTS

NUCLEAR ENERGY: PROSPECTIVE AND OPPORTUNITIES

STF S.p.A. has acquired large experience in designing and manufacturing

Heat Transfer Products (HTP) within the Conventional Island ofNuclear

Power Plants, particularly Low and High Pressure Feed-Water Heater.

TECHNOLOGY AND INNOVATION

HTP are designed and manufactured according to the most restrictive

quality and safety criteria of nuclear plants, always complying with all

the Customer requirements and meeting or exceeding the desired

performances.

STF services include the installation of HTP into the Power Plant and an

after-sales assistance dedicated to help Customers during operation and

maintenance through the supply of spare parts and on-site assistance,

but also proposing new possible engineering solutions.

Tubesheet under cladding with

Inconel 600

Tube bundle

Finite Element Analysis of HP Feedwater Heater

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STFS.p.A.Via Robecco, 2020013 Magenta (MI) ItaliaTel: +39 02 972091Fax: +39 02 9794977www.stf.ite-mail: stf@stf.it

BWE

Burmeister & Wain Energy A/SLundtoftegrdsvej 93ADK-2800 Kgs. Lyngby - DenmarkTel: +45 39 45 20 00Fax: +45 39 45 20 05www.bwe.dk

e-mail: info@bwe.dk

BWE Energy India Pvt. LtdNo. 43, KB Dasan RoadTeynampetChennai - 600 018TamilNadu, IndiaTel: +91 44 24 32 8101/2Fax: +91 44 24 32 8103

e-mail: info@bweenergy.in