Section08_A4.pdf

8/11/2019 Section08_A4.pdf

1/806

P-1 of 2

M a i n C o n t e n t s - a

Main Table of ContentsOperation and Maintenance Instruction ManualVolume 2 Maintenance and System Description Manual

Book No Section No Item Drawing No

Volume 2 Section 8 GeneratorManual

8.1 740MVA T/G INSTRUCTION LIST EKC003097 8.2 740MVA TURBINE GENERATOR DESIGN DATA EKC003098

8.3 740MVA GENERATOR STRUCTURE EKC0030998.4 FILLING AND RELEASING OF H2 GAS EKC003087

8.5 GAS CONTROL SYSTEM AND SHAFT SEAL OIL SYSTEM EKC003100

8.6 OPERATION OF GENERATOR EKC0027008.7 ACTION TO BE TAKEN ON ALARMS FROM GAS CONTROL

SYSTEM AND SHAFT SEAL OIL SYSTEM EKC003101 8.8 STATOR COOLING WATER SYSTEM EKC003102 8.9 PERIODIC OPERATIONAL INSPECTION AND TESTS EKC002435

8.10 PERIODIC INSPECTION CHECK SHEET EKC002382

8.11 REGULAR INSPECTION OF HYDROGEN COOLEDTURBINE GENERATOR E1O00069

8.12 DRYING THE TURBINE GENERATOR WINDINGS E1O000J7

8.13 DIELECTRIC STRENGTH TEST OF TURBINE GENERATORARMATURE WINDINGS EKC002852

8.14 MAINTENANCE OF GAS TIGHTNESS AT ROTOR WINDINGLEADS EKC002433

8.15 PREPARATIONS FOR DISASSEMBLY AND REASSEMBLY

OF GENERATOR E1O000H6 8 16 INSTALLATION AND ASSEMBLY OF GENERATOR EKC003063


2/806

P-2 of 2

M a i n C o n t e n t s - a

Main Table of ContentsOperation and Maintenance Instruction ManualVolume 2 Maintenance and System Description Manual

Book No Section No Item Drawing No

Volume 2 Section 8 GeneratorDrawing

8.30 GENERATOR CHARACTERISTIC DATA VA1-TSB-00MKA-E-M1B-DAS-31108.31 740MVA Generator Rating Plate VA1-TSB-00MKA-E-M1B-DLB-3111

8.32 740MVA GENERATOR OUTLINE VA1-TSB-00MKA-E-M1B-DRD-31008.33 740MVA GENERATOR TERMINAL

BUSHING ASSEMBLY VA1-TSB-00MKA-E-M1B-DRD-31018.34 DETAIL OF AUX. TERMINAL BOX VA1-TSB-00MKA-E-M1B-DGA-3109

8.35 GENERATOR SOLE PLATES & ANCHOR

BOLTS VA1-TSB-00MKA-E-M1B-DFN-31248.36 ARRANGEMENT OF SOLE PLATE FOR

740MVA GENERATOR VA1-TSB-00MKA-E-M1B-DRD-3107 8.37 LOCATION OF R.T.D FOR 740MVA

GENERATOR VA1-TSB-00MKA-E-M1B-DGA-3108 8.38 DIAGRAM OF GAS CONTROL SYSTEM VA1-TSB-00MKG-E-M1B-PFD-3113

8.39 DIAGRAM OF SHAFT SEAL OIL SYSTEM VA1-TSB-00MKW-E-M1B-PFD-31148.40 DIAGRAM OF STATOR COOLING WATER

SYSTEM VA1-TSB-00MKF-E-M1B-PFD-31128.41 DESIGN OUTLINE OF GENERATOR VENT

TO ATMOSPHERE VA1-TSB-00MKA-E-M1B-DRD-31058.42 SPECIFICATION OF TEMPERATURE GAUGE VA1-TSB-00MAY-I-M1B-SPC-55308.43 INSTRUMENT LIST ***VA1-TSB-00MAY-I-M1B-SPC-55758 44 OUTLINE OF 740MVA GENERATOR NEUTRAL


3/806


4/806


5/806


6/806


7/806


8/806

1 11

E KC0 0 3 0 9 8 - a

Vi e t n a m Li l a ma Co r p or a t i o n

740MVA Tur bi ne Gen er at or

De s i gn Da t a

740MVA Tur bi ne Gene r a t or Des i gn Dat a


9/806

E KC0 0 3 0 9 8 - a

2 11 à –¾ • ‘ xpl anat i on

–¼ Ì TITLE

740MVA Tur bi ne Gene r at or Des i gn Dat a

‹q æ¼ CUSTOMER • F Vi e t na m / Li l a ma Cor p or a t i o n

Œn ‹ Ší EQ/ SYS. • F 740MVA Tur bi ne Gene r at or

»”Ô JOB • F M231001 , M231002 RT 2201

ƒvƒ‰“ƒg PROJECT • F VVA1 , VVA2


10/806

E KC0 0 3 0 9 8 - a

3 11à –¾ • ‘ Expl anat i on

1. General···························································································································· 4

2 Rating

······························································································································

4

2.1.

Generator ··············································································································4

3 Characteristic Curves ··································································································· 5

3.1. Estimated Saturation and Synchronous Impedance Curves ································5

3.2. Estimated “V” Curves ·························································································6

3.3.

Estimated Reactive Capability Curves ·································································7

4 Auxiliary System ··············································································································· 8

4.1.

Gas Control System······························································································8

4.2.

Gas Cooling System ·····························································································8

4.3.

Shaft Sealing System····························································································9

4.4. Stator Cooling Water System ···············································································9

4.5. Generator Unbalanced Load Capability ·······························································9


11/806

E KC0 0 3 0 9 8 - a


1 General

This instruction manual gives overall data and descriptions of 740,000kVA generator and its auxiliary

units.

The rated electrical power output of generator is 629,000kW at a power factor of 0.85 lagging. The

generator is mechanically driven by its associated steam turbine, electrically excited by the static thyristor

rectifier excitation system and internally cooled by hydrogen gas.

2 Rating

2 1 Generator

Rating: TAKS-2P-740,000kVA-3000rpm-LCH-26,000V-16,433A-50Hz-0.85PF-0.52MPag

(a) Cold gas temperature (Outlet of H2 coolers): 46 • Ž

(b) Alarm temperature of cold gas temp. high: 48 • Ž


12/806

E KC0 0 3 0 9 8 - a


3 Characteristic Curves

3 1 Estimated Saturation and Synchronous Impedance Curves

0.52MPag


13/806

E KC0 0 3 0 9 8 - a


3 2 Estimated V

Curves

0. 52MPag


14/806

E KC0 0 3 0 9 8 - a


3 3 Estimated Reactive Capability Curves

0. 52MPag


15/806

E KC0 0 3 0 9 8 - a


4 Auxiliary System

4 1 Gas Control System

(a) Amount of gas space in generator casing: 115 m3

(b) Amount of carbon dioxide required for removing air from casing

(Generator at standstill or low speed): 175 m3

(c) Amount of carbon dioxide required for removing hydrogen from casing

(Generator at standstill or low speed): 230 m3

(d) Amount of hydrogen required for filling casing to 90 percent purity

at the atmospheric pressure (Generator at standstill): 230 m3

(e) Amount of hydrogen required for increasing pressure in casing

from 0 to 0.52MPag: 600 m3

(f) Mi i i f li d h d 99 %


16/806

E KC0 0 3 0 9 8 - a


4 3 Shaft Sealing System

(a) Maximum oil flow to shaft seals in normal operation at 0.52MPag: 195 L/min

(b) Gas side oil flow in the above: 20 L/min

(c) Differential between seal oil and hydrogen pressure: 50 kPa

(d) Alarm of the above differential pressure low: 30 kPa

(e) Alarm of filter differential pressure high: 20 kPa

4 4 Stator Cooling Water System

(a) Water flow through stator winding: 980 L/min

(b) Cooling water inlet temperature: 46 • Ž

(c) Alarm temperature of stator winding temp. high: 10 • Žabove temperature

at full load


17/806

E KC0 0 3 0 9 8 - a


This page is intentionally blanked.


18/806

E KC0 0 3 0 9 8 - a


Œo —ð • ‘

Re vi s i on Hi s t or y( f or i nt e r n a l u s e )

Ï X

REV. PAGE

Ï X‰Ó Š‹y ‚Ñ “à —e

CHANGED PLACE AND CONTENT

³”F

APPROVED

’² ¸

REVIEWED

’S “–

PREPARED

‚• Initial Issue.Written in

page 2.

Written in

page 2.

Written in

page 2.


19/806

1 33

E KC0 0 3 0 9 9 - a

Vi e t n a m Li l a ma Co r p or a t i o n

740MVA GENERATOR STRUCTURE


20/806

E KC0 0 3 0 9 9 - a

2 33 à –¾ • ‘ xpl anat i on

–¼ Ì TITLE

740MVA GENERATOR STRUCTURE

‹q æ¼ CUSTOMER • F Vi e t na m / Li l a ma Cor p or a t i o n


»”Ô JOB • F M231001 , M231002 RT 2201

ƒvƒ‰“ƒg PROJECT • F VVA1 , VVA2


21/806

E KC0 0 3 0 9 9 - a


Table of Contents

1. Introduction 5

2. Precaut ions for Safety

5

3. Generator Structure

11

3.1 General ···············································································································11

3.2 Stator Frame and Stator Core ·············································································12

3.2.1 Stator Frame ····························································································12

3.2.2 Spring Mounting······················································································12

3.2.3 Stator Core·······························································································13

3.3 Stator Winding (Armature Winding) ·································································15

3.3.1 Stator Bar and Insulation ·········································································15

3.3.2 Insulating connection Tube ·····································································16

3.4 Generator Terminal Plate ···················································································18


22/806

E KC0 0 3 0 9 9 - a


This Page Intentionally Left Blank


23/806

E KC0 0 3 0 9 9 - a


1. Introduction

This manual is written to ensure safe handling of the 740MVA Generator Structure. Before

operation, maintenance and inspection, be certain to read this manual for proper use of the

equipment. This manual should be kept near the equipment so it can be readily referenced.

2. Precautions for Safety

Signs and messages in this manual and on the equipment body are important for management,

operation, maintenance and inspection. They are given to avoid possible injuries and damages

as well as to ensure correct handling of the equipment. The following signs and short messages

should thoroughly be understood before reading this manual. It is advised that you also read

the instruction manuals of related equipment and components.

IMPORTANT MESSAGES

Read this manual and follow its instructions. Signal words such as DANGER, WARNING, two kinds of CAUTION,and NOTE, will be followed by important safety information that must be carefully reviewed.

Indicates an imminently hazardous situation, which will result in death or serious injury if you

DANGER!


24/806

E KC0 0 3 0 9 9 - a


WARRANTY AND LIMITATION OF LIABILITY

TOSHIBA CORPORATION AND THE USER’S DIRECT SELLER ACCEPT NO

LIABILITY FOR ANY INJURY, LOSS OR DAMAGE THAT RESULTS OR MAY

APPLICATION

This Toshiba Steam Turbine and Generator Manual does not include all information necessary for every possible

contingency concerning the installation, operation and maintenance of the Toshiba Steam Turbine and Generator

Unit.

Should you require further information about the Toshiba Steam Turbine and Generator Unit or should a particular

situation arise which is not covered by this Toshiba Steam Turbine and Generator Manual, the matter should be

referred to Toshiba (contact details are specified at page 2 of this Manual).


25/806

E KC0 0 3 0 9 9 - a


QUALIFIED PERSONS ONLY

AS A MINIMUM SAFETY REQUIREMENT, ONLY A “QUALIFIED PERSON”

SHOULD INSTALL, OPERATE OR MAINTAIN A TOSHIBA STEAM TURBINE

AND GENERATOR UNIT. THIS TOSHIBA STEAM TURBINE AND GENERATOR

MANUAL IS WRITTEN SOLELY FOR USE BY A “QUALIFIED PERSON”.

ONLY A “QUALIFIED PERSON” SHOULD INSTALL, OPERATE AND MAINTAIN

THE TOSHIBA STEAM TURBINE AND GENERATOR UNIT IN ACCORDANCE

WITH ALL APPLICABLE LAWS, REGULATIONS AND SAFETY PROCEDURES.

TO BE A “QUALIFIED PERSON”, YOU SHOULD HAVE SATISFIED ALL OF THE

FOLLOWING CRITERIA:

(1) YOU MUST HAVE CAREFULLY READ AND UNDERSTOOD THETOSHIBA STEAM TURBINE AND GENERATOR UNIT MANUAL AND ANY

OTHER MANUALS OF THE ASSOCIATED DEVICES AND COMPONENTS

OF THE TOSHIBA STEAM TURBINE AND GENERATOR UNIT MANUAL.

(2) YOU MUST HAVE RECEIVED TRAINING OFFERED BY TOSHIBA.

BEFORE YOU INSTALL, OPERATE OR MAINTAIN THE TOSHIBA STEAM


26/806

E KC0 0 3 0 9 9 - a


SAFETY SIGN

(1) To ensure safety, all the SAFETY SIGNS (including DANGER LABELS, WARNING LABELS, CAUTION

LABELS and NOTE LABELS) must be read and understood

(2) All the SAFETY SIGNS (including DANGER LABELS, WARNING LABELS, CAUTION LABELS and NOTE

LABELS) must be kept in such condition that they can be easily seen. They must be clear enough to be

clearly visible and never be removed or blocked from view.


27/806

E KC0 0 3 0 9 9 - a


■ When the rotor extracted from, or inserted into the stator, be sure to

protect the inner walls of the stator core from damage.

If the punchings are burred or shorted together at the tooth tips, this would permit circulating currents,induced by the magnetic flux in the core, resulting in a hot spot and possible damage to the core.

CAUTION


28/806

E KC0 0 3 0 9 9 - a




29/806

E KC0 0 3 0 9 9 - a


3. Generator Structure

3.1 General

The generator is completely enclosed and, in operation uses hydrogen gas as the cooling

medium. The ventilation system including the fans and gas coolers is self-contained andcompletely enclosed to prevent entrance of dirt and moisture. Stator winding is directly cooled

by demineralized water and rotor winding are directly cooled with the hydrogen gas.

The generator casing is substantially cylindrical in shape and of welded gastight construction.

The outer end shields at either end of the casing are also of welded gastight construction and

support the generator bearings and shaft sealing devices. The generator casing and outer end

shields are of the explosion-proof type.

The stator core is supported by spring plates in the stator frame to isolate core vibration. The

rotor is of the gap pickup direct cooling type. Both ends of the rotor pass through the end

shields, and shaft seals are used to prevent hydrogen gas leakage. The generator is designed

for continuous operation and is constructed to withstand a sudden change in load and

three-phase shortcircuit. Various kinds of supervising and controlling instruments are provided

for keeping the generator in satisfactory operation.

Accessories include a gas control device, a cooling water control device for controlling the gas

temperature inside the generator as well as supervising and controlling device, and various


30/806


31/806


32/806

E KC0 0 3 0 9 9 - a



33/806

E KC0 0 3 0 9 9 - a


3.3 Stator Winding Armature Winding)

3.3.1 Stator Bar and Insulation

The stator winding is formed by insulated bars assembled in the slots of the stator core, jointed

at the ends to form coils, and connected to the proper phase belts by bus rings.

The stator bars shown in Fig.4 are composed of insulated copper strands arranged in the formof rectangular bars. As shown in Fig.3, each strand is so assembled that it occupies, for an

equal length of the bar, every radial position in the bar, which is accomplished by a spiral

progression of each strand around the bar, called “Reobel” transposition. This arrangementavoids eddy current losses under load conditions which would otherwise be caused by the

self-inductive magnetic flux distribution in the coil slot.

Required numbers of mica tapes are applied half lapped on the molded strands by using

automatic taping machine with constant tension device. After taping, stator bars are treated byvacuum to remove bubbles included in the bar insulation. Finally, the bars are molded into

required form. The peripheral parts of the insulator in the slot are coated with a semi-conductivecorona-inhibitive material, and the portion of the bar just outside the slot is protected with a

corona-inhibitive tape.

The end portions of stator windings are securely laced with glass cord to the binding bands,which are molded polyester-glass rings supported with end flanges through the binding band

supports. These supports are made from non magnetic steel and insulated.


34/806

E KC0 0 3 0 9 9 - a



35/806

E KC0 0 3 0 9 9 - a



36/806

E KC0 0 3 0 9 9 - a


3.4 Generator Terminal Plate

The main armature leads extend through the bottom of the generator casing and the generator

terminal plate.

On this machine, connections are provided at the collector end portion. The terminal plate is

made from nonmagnetic material to prevent inducted currents from the current flow in the

armature leads. Drain is located in the terminal plate to prevent accumulation of oil or wateraround the connections. Gaskets are provided between the terminal plate and high-voltage

bushing flange to prevent hydrogen leakage. (See Fig.6)


37/806

E KC0 0 3 0 9 9 - a


3.5 High-voltage Bushing and Current Transformer

The armature connections extend through the terminal plate by means of gas-tight, porcelain

insulated high-voltage bushings.

Site assembly of the bushings, armature leads in the terminal box, and covering of the

associated joints are accomplished after stator frame on base.

Mounting arrangement of the bushings is shown in Fig.7. Shows the assembly of a

bushing-type current transformer. The bushing type current transformer is mounted as enclosing

the terminal bushing and is used to measure generator output current and to protect and control

the generator. The bushing type current transformer is fastened to the terminal plate with studs.


38/806

E KC0 0 3 0 9 9 - a


3.6 Rotor

3.6.1 Rotor Assembly

The rotor shaft is machined from a solid forging of Ni-Cr-Mo-V alloy steel. It’s quality has

been corroborated by mechanical, chemical, and metallurgical inspection and non-destructive

testing. The rotor core is slotted to accommodate rotor coils, and the rotor coils are secured in position with wedges that stand the centrifugal force of the coils.

As shown in Fig.8, the rotor pole portions are provided with semi-circular-shaped grooves

(cross slot) in the right angle direction to the rotor shaft axis for the purpose of equalizing therigidity in the magnetic pole direction and the right angle direction to it. The rotor pole, fan

bosses and collector fan can be fitted with balance weights to reduce rotor vibration. The

coupling and fan boss on turbine end are machined from the rotor shaft. The collector end fan boss is made of a shrink-fit forging of alloy steel. The axial flow fan, with wing-shaped blades,

is made of high-strength aluminum alloy and is engaged and bolted to the fan boss.


39/806

E KC0 0 3 0 9 9 - a


3.6.2 Rotor Winding Field Winding) and Retaining Ring

The rotor conductors are machined to provide gas ducts, formed into shape, and put into the

slots in the rotor core. Fiber reinforced insulator is used for layer insulation and for the slot

insulation. A creepage block of fiber-glass-reinforced insulator, capable of withstanding the

centrifugal force of the conductor, is seated between the top of the conductor and the rotor

wedge to ensure a high insulation resistance to ground. Glass-base insulating blocks are set between coils to check the displacement of rotor end windings due to thermal stress and

centrifugal force. In addition, the end windings are supported with retaining rings shrink-fitted

on the core end. The retaining ring is secured to the rotor with an retaining ring key. A

glass-base annular insulator is set between retaining ring and the top of the coils for isolation

from the ground. The retaining ring is made of nonmagnetic Mn-Cr alloy steel with high

mechanical strength.

The rotor core and retaining ring are brought in direct contact with each other, and to flow

current in between in case of an unbalanced load or a sudden short-circuit fault. To reduce theeffect of this current, the engagement between the retaining ring and rotor shaft is metallized for

a reduced contact resistance. An amortisseur is provided under the retaining ring and the rotor

end wedge. Fig.9 shows arrangement of the retaining ring.

Fig.10 shows the arrangement of rotor winding.


40/806

P r o pr i e t ar y I n

f or m a t i on

© T o s h i b a C or p or a t i on2 0 1 1 ,A l l Ri gh t s

R e s er v e d

Wedge

Rotation

Suction hole

Layer insulation

Wedge

Suction hol

Rotor wed e

Creepage block

Sucton hole

Rotation

F

g

1

A

A

M

N

O

T

H

R

O

O

W

N

N


41/806

E KC0 0 3 0 9 9 - a


3.7 Outer End Shield and Bearing

Fig.11 shows the outer end shield and bearing.


42/806


43/806

E KC0 0 3 0 9 9 - a



44/806

E KC0 0 3 0 9 9 - a


3.8 Shaft Sealing Device

A shaft sealing device is installed inside the machine to come inside of the bearing, and is used

to prevent hydrogen gas leaking from the machine through the shaft penetrant part.

Fig.13 shows the general assembly of the shaft sealing device. The seal casing has two seal

rings, and is mounted on the outer end shield. The collector end seal casing is split into inner and

outer halves; an insulating plate is provided between the inner and outer halves, and anotherinsulating plate is provided between the outer half casing and the outer end shield. These

insulating plates serve to prevent shaft current.

Fig.14 shows the seal ring and the flow of sealing oil. There are two seal rings of inner

(hydrogen side) and outer (air side) ring. The seal ring which is divided into two half-circles is

supported with upper and lower springs to follow the movement of the rotor shaft, and is

designed to ensure the continuity of oil film.

The seal ring is always supplied with sealing oil which is 50kPa higher than the insidehydrogen gas pressure. The sealing oil passes through the gap between the seal ring and shaft,

and is drained dividing into the hydrogen side and air side.


45/806

E KC0 0 3 0 9 9 - a



46/806

E KC0 0 3 0 9 9 - a


3.9 Collector and Brush

The brushes and collector rings are ventilated by an open circuit system in which the cooling

air is circulated through the air filter mounted on the air inlet.

The cooling air is sucked in from the air feed port of the operation floor and is discharged out

of the vent port of the collector cover

3.9.1 Collector Ring

The collector rings consist of negative and positive poles, which are made of high quality alloy

steel and shrunk onto insulated shaft.

As illustrated in Fig.15, the outer surface of the collector ring has spiral grooves for cooling

and removal of dust. The collector ring has axial holes for cooling ventilation and is fitted with a

shaft mounted fan between both rings for reducing temperature rise caused by excitation current.

E KC0 0 3 0 9 9


47/806

E KC0 0 3 0 9 9 - a


3.9.2 Brush and Brush Holder

The rotor winding of the generator is directly cooled. Its exciting current is large and

necessitates large-capacity collector rings and a number of brushes.

As illustrated in Fig.16, the brush holder is of the magazine type, capable of attaching and

detaching four brushes en bloc. All brush holders are circumferentially arranged. By turning the

handle 90 • ‹, brush holders can be attached or detached to the brush holder receiver.Accordingly, in-service brush inspection and replacement can be carried out safely.

The brush for the generator is made of natural graphite, and has low friction and high

self-lubricating characteristic. The brush is fitted with a pigtail wire having a crimp-style

terminal on its end.

The constant-pressure spring in the brush holder forces the brush in the racial direction, and

the brush needs no pressure adjustment as it wears.

E KC0 0 3 0 9 9


48/806

E KC0 0 3 0 9 9 - a


3.10 Hydrogen Gas Cooler

Four gas coolers are installed upright in the four corners of the stator frame. They use cooling

water to remove heat from hydrogen gas that is heated while being circulated within the

generator. Fig.17 shows installation of a typical, vertical-type, hydrogen gas cooler. The

hydrogen gas cooler is composed of a heat exchange section having a bundle of copper alloy

finned tubes, upper and lower tube sheets holding the upper and lower ends of the tube bundle,

and upper and lower water boxes.

Heat exchange between the cooling water and hydrogen gas is carried out by the counter-flow

system. Hot hydrogen gas enters the cooler from the cooling water drain side, and the cooled

hydrogen gas leaves the cooler from the cooling water supply side.

That part of the hydrogen gas cooler which passes through the stator frame is totally sealed to

prevent hydrogen gas leaking from the machine. At the lower part, a gland packing type seal is

used which is slidable to absorb the expansion and contraction of the cooler due to temperature

change.


49/806


f or m a t i on

© T o s h i b a C o

r p or a t i on2 0 1 1 ,A l l Ri gh t s

R e s er v e d

F

G

1

1

G

N

R

A

O

S

C

O

D

A

W

N


50/806


f or m a t i on

© T o s h i b a C o

r p or a t i on2 0 1 1 ,A l l Ri gh t s

R e s er v e d

F

G

1

2G

N

R

A

O

S

C

O

D

A

W

N

E KC0 0 3 0 9 9 - aŒo —ð • ‘


51/806

E KC0 0 3 0 9 9 - a

33 33à –¾ • ‘ Expl anat i onRevision History (for internal use)

Ï X

REV. PAGE

Ï X‰Ó Š‹y ‚Ñ “à —e

CHANGED PLACE AND CONTENT

³”F

APPROVED

’² ¸

REVIEWED

’S “–

PREPARED

‚• ‰ ”Å INITIAL ISSUEDWritten in

page 2.

Written in

page 2.

Written in

page 2.


52/806


53/806


54/806


55/806


56/806


57/806


58/806


59/806


60/806


61/806


62/806


63/806


64/806


65/806


66/806


67/806


68/806


69/806


70/806


71/806


72/806


73/806


74/806


75/806

1 of 22

E K C 0 0 3 1 0 0 - a


76/806

Vi etnam Li l ama Corporat i on

740MVA Turbi ne Generat or

Gas Cont rol Syst emAnd Shaf t Seal O l Syst em

I nst ruct i on Manual

2 of 22

E K C 0 0 3 1 0 0 - a


77/806

–¼• Ì TITLE

Ga s Cont r o l Sys t e m And Sha f t Se a l Oi l Sys t e m

‹q æ¼ CUSTOMER • F Li l ama Cor por a t i on


»”Ô J OB • F M231001, M231002, RT 2201

ƒvƒ‰ƒ“ ƒg PROJ ECT • F VVA1, VVA2,

3 of 22

E K C 0 0 3 1 0 0 - a


78/806

Table of Contents

Table of Contents·················································································································· 3

1. Introduction··················································································································· 5

2. Precautions for Safety··································································································· 5

3. Scope ····························································································································· 11

4.

Related Documents······································································································ 11

5. Explanation of Shaft Seal Oil System ······································································· 11

5.1 Shaft Seal Oil Circuit ·························································································11

5.2 Measuring Shaft Seal Oil Amount ·····································································16

5.3

Units Disconnection from System ·····································································17

6. Explanation of Gas Control System·········································································· 19

6.1

Continuous Scavenging······················································································19

6.2 Hydrogen-Gas Purity ·························································································19

6.3

Hydrogen-Gas Pressure······················································································20

7. Alarm Lists··················································································································· 21

E K C 0 0 3 1 0 0 – a

4 of 22


79/806


80/806

E K C 0 0 3 1 0 0 – a

6 of 22


81/806




RESULT FROM ANY FAILURE TO OBSERVE THE PROCEDURES,

INSTRUCTIONS, WARNINGS, DESCRIPTIONS, DATA AND INFORMATION

APPLICATION



Unit.


situation arise which is not covered by this Toshiba Steam Turbine and Generator Manual, the matter should bereferred to Toshiba (contact details are specified at page 4 of this Manual).

E K C 0 0 3 1 0 0 – a

7 of 22


82/806

QUALIFIED PERSONS ONLY

AS A MINIMUM SAFETY REQUIREMENT, ONLY A “QUALIFIED PERSON”

SHOULD INSTALL, OPERATE OR MAINTAIN A TOSHIBA STEAM TURBINE

AND GENERATOR UNIT. THIS TOSHIBA STEAM TURBINE AND GENERATOR

MANUAL IS WRITTEN SOLELY FOR USE BY A “QUALIFIED PERSON”.

ONLY A “QUALIFIED PERSON” SHOULD INSTALL, OPERATE AND

MAINTAIN THE TOSHIBA STEAM TURBINE AND GENERATOR UNIT IN

ACCORDANCE WITH ALL APPLICABLE LAWS, REGULATIONS AND SAFETYPROCEDURES.

TO BE A “QUALIFIED PERSON”, YOU SHOULD HAVE SATISFIED ALL OF

THE FOLLOWING CRITERIA:

(1) YOU MUST HAVE CAREFULLY READ AND UNDERSTOOD THE

TOSHIBA STEAM TURBINE AND GENERATOR UNIT MANUAL AND ANY

OTHER MANUALS OF THE ASSOCIATED DEVICES AND COMPONENTS

OF THE TOSHIBA STEAM TURBINE AND GENERATOR UNIT MANUAL.

(2) YOU MUST HAVE RECEIVED TRAINING OFFERED BY TOSHIBA.

BEFORE YOU INSTALL, OPERATE OR MAINTAIN THE TOSHIBA STEAM

TURBINE AND GENERATOR UNIT, YOU MUST HAVE BEEN SO

AUTHORIZED BY THE PURCHASER

E K C 0 0 3 1 0 0 – a

8 of 22


83/806

SAFETY SIGN






E K C 0 0 3 1 0 0 – a

9 of 22


84/806

■ In case the main seal oil pump and emergency seal oil pump cannot

be operated, lower the hydrogen-gas pressure in the generator

casing below 50kPag.

Hydrogen gas may leak and an explosion may potentially result.

■ In case supply pressure of shaft seal oil cannot be maintained,

dissociate and shut down the generator, release hydrogen gas in the

generator casing through the release pipe and lower the hydrogen-

gas pressure to atmospheric pressure. And fill carbon dioxide in the

generator casing.

Hydrogen-gas pressure is lowered, or hydrogen gas may leak and an explosion may potentially result.

■Always assume the by-pass valve of the float-trap to be closed.

Confirm hydrogen gas pressure in the generator is less than 10kPag

when you open the by-pass valve, and observe continuously so that

the oil level should not fall more than the center of level gauge.

Hydrogen gas may leak through the by-pass valve, air detraining section, oil drain pipe and outer oil

DANGER!

E K C 0 0 3 1 0 0 – a

10 of 22


85/806

■ In case the DC power to the pump motor cannot be supplied, makepreparation to lower gas pressure in the generator casing by

isolating the generator load and releasing hydrogen gas.

An accident involving generator damage may result.

■ Keep pressure in the generator is more than 10kPag while shaft seal

oil system is operating.

Oil drain flow may be bad and the oil leakage to inside of generator may result.

■ Do not allow unauthorized persons to enter your working area.

Clarify your off limits area by loping and displaying such as [Keep out].

Moving parts cause deaths or serious injuries.

■ Confirm grounding of your equipment before conducting a test.

Electric leakage or failure of your equipment causes a fire or an electric shock.

■ Prepare a stable scaffold and fall prevention & personal protective

equipment when working at an elevated place.

ARNING!

E K C 0 0 3 1 0 0 – a

11 of 22


86/806

3. Scope

This manual describes the method to operate the gas and shaft seal oil systems of the hydrogen-

cooled turbine generator.

4. Related DocumentsRefer to the system diagrams of the shaft seal oil system and gas system for use as system

diagrams in operating the generator under this manual.

Refer to the instructions EKC003087 “Instruction Manual for Filling and Releasing of H2 Gas” for filling and releasing hydrogen gas in the generator casing.

Refer to the instructions EKC003101 “Instruction Manual for Action to be Taken on Alarms

from Gas Control System and Shaft Seal Oil System” on actions to be taken on alarms.

5. Explanation of Shaft Seal Oil System

5.1 Shaft Seal Oil CircuitDepending on operational condition of the pumps in the bearing lubricating oil system and shaft

seal oil system of the turbine generator, the circuits for shaft seal oil are divided as follows.

a. Normal Operation

In normal operation, receiving oil cooled to a predetermined temperature from the bearing

lubricating oil system of the turbine generator as illustrated below, the shaft seal oil system

E K C 0 0 3 1 0 0 – a

12 of 22


87/806

The supply pressure of shaft seal oil is monitored by the pressure gauge and by differential-

pressure gauge. During generator operation, supply pressure for shaft seal oil is always adjusted

50kPag higher than the generator casing pressure. Therefore, the supply pressure for shaft seal

oil also will be automatically adjusted in accordance with variations in generator casing

pressure.

b. Emergency Shaft Seal Oil Circuit

(a) When Emergency Seal Oil Pump is Running

In case the main seal oil pump cannot be operated, the emergency seal oil pump will actuate

automatically and the oil will be fed to the shaft seals.

■ In case the DC power to the pump motor cannot be supplied, make

preparation to lower gas pressure in the generator casing byisolating the generator load and releasing hydrogen gas.

An accident involving generator damage may result.

Turbine-Lube Oil Tank Oil CoolerTurbine- Lube Oil Pump Emergency Seal Oil Pump

DANGER!

E K C 0 0 3 1 0 0 – a

13 of 22


88/806

■ In case the main seal oil pump and emergency seal oil pump cannot

be operated, lower the hydrogen-gas pressure in the generator

casing below 50kPag.

Hydrogen gas may leak and an explosion may potentially result.

In case the main seal oil pump and emergency seal oil pump cannot be operated, the generator

will be operated at supply oil pressure from the bearing lubricating oil system. During this

operation, hydrogen gas will be sealed by supply oil pressure of the bearing lubricating oil

system and the hydrogen-gas pressure inside the generator casing has to be lowered below

50kPag. The oil will be fed to the shaft seals through the differential-pressure regulating valve,

bypassing the pump.

Turbine-

Lube Oil

Turbine-

Lube OilOil Differential-Pressure

Regulating Valve

Shaft

S l

Float-Trap

Hydrogen

detraining section

Air

detraining

DANGER!

E K C 0 0 3 1 0 0 – a

14 of 22


89/806

‡ When the closed loop circulate operation is carried out at the rated hydrogen gas pressure,

the operation should not be over 1 hour.

‡A When it is necessary to carry out the closed loop circulate operation over 1hour, the

hydrogen pressure must be lowered under 50kpag beforehand.

‡B Monitor continuously the seal oil temperature on the shaft seal that should be 60ºC or under

to ensure the hydrogen seal function. In closed loop circuit operation, the temperature of

the seal oil that does not go through the main oil tank and the oil cooler, have the tendency

of becoming higher. The temperature should be measured on the return pipe just before the

float trap with a liquid-in-glass thermometer.

‡C When the main seal oil pump is started at the normal operation, hunting phenomena in the

Differential-Pressure

Regulating Valve

Float

Trap

Main

Seal

Pump

Shaft

Seals

Air

detraining

section

Hydrogen

detraining

section

Relief

Valve

E K C 0 0 3 1 0 0 – a

15 of 22


90/806

■ Do not operate the main seal oil pump and emergency seal oil pump

simultaneously on the closed loop circuit (without turbine lube oilsystem).

If the two pumps are operated simultaneously, temperature of the main seal oil pump may rise due to

stirring heat caused by a difference in discharge, potentially damaging the pumps.

■ In case supply pressure of shaft seal oil cannot be maintained,

dissociate and shut down the generator, release hydrogen gas in the

generator casing through the vent pipe and lower the hydrogen-gas

pressure to atmospheric pressure. And fill carbon dioxide in the

generator casing.

Hydrogen-gas pressure is lowered, or hydrogen gas may leak and an explosion may potentially result.

■ In case of closed loop circulate operation (without turbine lube oil

NOTE

DANGER!

E K C 0 0 3 1 0 0 – a

16 of 22


91/806

5.2 Measuring Shaft Seal Oil Amount

■ Operate in the correct sequence.

Otherwise oil leakage or other accident may potentially result.

This section describes the method to measure the amount of shaft seal oil to measure the

consumption of hydrogen gas.

a. Total Amount of Seal Oil Supply

1) Open Valves x0MKW40AA913 and x0MKW40AA015 installed front/rear of the flow

meter in the downstream of the differential-pressure regulating valve. Then slowly

close Valve x0MKW40AA014 by paying attention to the seal differential pressure.

2) Measure the amount of supply seal oil on the flow meter and record the supplied

amount.3) After finishing measurement, open Valve x0MKW40AA014 and close Valves

x0MKW40AA913 and x0MKW40AA015 installed front/rear of the flow meter

b. Hydrogen Side Amount of Seal Oil Supply

Let us assume that the bypass valve of the float-trap is closed, and that the level of oil in the

float-trap can be read on the liquid level gauge.

NOTE

E K C 0 0 3 1 0 0 – a

17 of 22


92/806

5.3 Units Disconnection from System

■ Operate in the correct sequence.

Otherwise oil leakage or other accident may potentially result.

a. Disconnecting Main Seal Oil Pump and Relief Valve x0MKW40AA602

1) Start up the emergency seal oil pump.

2) Shut down the main seal oil pump and close its Inlet Valve x0MKW40AA007

and Outlet Valve x0MKW40AA032 of relief valve. Then close Outlet Valve

x0MKW40AA704 of the main seal oil pump.

The generator units can be serviced for checks and repairs after operating as described

above.

b. Disconnecting Float-Trap1) Change the oil level gauge of the float-trap from the float-trap to the bypass tank.

Close Valves x0MKW30AA003 and x0MKW30AA006. Open Valves

x0MKW30AA904 and x0MKW30AA905.

2) Adjust the opening of Outlet Valve 0MKW30AA002 of the bypass tank and

stabilize the oil the bypass tank.

NOTE

E K C 0 0 3 1 0 0 – a

18 of 22


93/806

c. Disconnecting Differential-Pressure Regulating Valve x0MKW40AA101

1) Adjust the opening Bypass Valve x0MKW40AA012 of the differential-pressureregulating valve in accordance with indication on the differential-pressure gauge.

Adjust to 50kPag in case the differential pressure currently indicated is below

50kPag. Otherwise adjust between 5k • ` 20kPag higher than the current

indication.

2) Close Outlet Valve x0MKW40AA014 of the differential-pressure regulating

valve with watching indication on the differential-pressure gauge. Check that

the differential pressure does not vary.3) Close Inlet Valve x0MKW40AA011 of the differential-pressure regulating

valve.

4) Close Differential-Pressure Detection Valves x0MKW40AA016 and

x0MKW40AA017 of the differential-pressure regulating valve.

The differential-pressure regulating valve can be serviced for checks and repairs after

operating as described above.

E K C 0 0 3 1 0 0 – a

19 of 22


94/806

6. Explanation of Gas Control System

6.1 Continuous Scavenging

A continuous scavenging system is used for this generator as a method to seal a hydrogen

gas in the generator casing.

Since the air-contained oil is supplied for the shaft seals from the shaft seal oil system.

This air is discharged from the oil and mixed to hydrogen gas in the section between inner

oil deflector and oil seal casing. Therefore the gas in this section must be continuouslyscavenged to prevent lowering hydrogen gas purity. The scavenging flow rate is 6000• `

10000 cc/min (total of turbine and collector end), from the hydrogen detraining sections at

turbine and collector end.

Refer to 5.4.1 Checking Continuous Scavenging Operation in the Instruction Manual for

Filling and Releasing of H2 Gas (Document No. EKC003087 ).

6.2 Hydrogen-Gas Purity

An alarm will be issued in case the purity of hydrogen gas scavenged from the hydrogen

detraining section lowers to 85% and 80%. During generator operation, gas in the

hydrogen detraining section is continuously flowed to the transmitter of the purity

indicator to measure the hydrogen-gas purity.

The flow rate to the gas purity transmitter is adjusted to about 500 to 1000cc/min by

needle valves (x0MKG50AA015 and x0MKG50AA016)

E K C 0 0 3 1 0 0 – a

20 of 22


95/806

6.3 Hydrogen-Gas Pressure

Hydrogen-gas pressure is monitored by the hydrogen-gas pressure gauge. An alarm is issued when

pressure varies to normal operating pressure 20kPag. Generally, hydrogen-gas consumption of a

generator can be expressed by the following formula:

This means that hydrogen gas inside the generator casing is consumed by the amount of hydrogen

dissolved in hydrogen side seal oil and of scavenging gas in it even if no hydrogen gas is leaked

through the gas system of the generator. Normally, hydrogen gas is automatically supplied through

the hydrogen-gas pressure regulating valve during steady generator operation, and hydrogen-gas

pressure in the generator casing can be maintained at desired pressure almost constantly. In case quick

boosting of hydrogen-gas pressure inside the generator casing is needed, hydrogen gas is suppliedthrough the bypass valve of the hydrogen-gas pressure regulating valve as in initial filling.

A hazard potentially exists if hydrogen-gas pressure inside the generator casing gradually lowers or

lowers in a short time. Troubleshoot the cause as soon as possible and examine the leakage location.

The hydrogen-gas pressure inside the generator casing slightly rises or lowers depending on the

generator hydrogen-gas temperature.

Consumption = Leakage amount

Amount of hydrogen

dissolved in hydrogen

side seal oil

+ +

Amount of

scavenging

gas

E K C 0 0 3 1 0 0 – a

21 of 22


96/806

7. Alarm Lists

Periodically test the level switches and pressure switches whether or not alarms function

properly, for each of the following items:

Shaft Seal Oil System:

Item Actuation Value Remarks

1 Discharge pressure of main

seal oil pump

Service pressure -100kPa

or lower.

See NOTE 1.

Emergency seal oil

pump actuated.

2 Differential pressure of duplex

seal oil strainer

20kPa or higher

3 Differential pressure of shaft

seal oil (Supply pressure of

shaft seal oil : Hydrogen-gas

pressure inside generator

casing)

30kPa or lower

4 Hydrogen detraining section

oil level

±10mm of sight-gauge

centerline

5 Air detraining section oil level -50mm or lower from

normal level

E K C 0 0 3 1 0 0 – a

22 of 22


97/806



98/806


99/806


100/806


101/806


102/806


103/806


104/806


105/806


106/806


107/806


108/806


109/806


110/806


111/806


112/806


113/806


114/806


115/806


116/806


117/806


118/806


119/806


120/806


121/806


122/806


123/806


124/806


125/806


126/806


127/806


128/806


129/806


130/806


131/806


132/806


133/806

1 of 38

E K C 0 0 3 1 0 2 - a


134/806

Vi etnam Li l ama Corporat i on

740MVA Turbi ne Generat or

St at or Cool i ng Wat er Syst em

I nst ruct i on Manual

2 of 38

E C K 0 0 3 1 0 2 - a

–¼• Ì TITLE

St a t o r Cool i ng Wa t e r Sys t e m


135/806

‹q æ¼ CUSTOMER • F Li l a ma Cor p r a t i on


»”Ô J OB • F M231001, M231002, RT 2201

ƒvƒ‰ƒ“ ƒg PROJ ECT • F VVA1, VVA2

E K C 0 0 3 0 2 - a

3 of 38

Table of Contents


136/806

1. Introduction 5

2. Precautions for Safety 5

3. Scope 13

4. Related Documents 13

5. Description 13

5.1 Design Data ········································································································13

5.2 General Description ··························································································· 14

6. Operation 21

6.1 Introduction ········································································································21

6.2 Operating Procedure ·························································································· 23

6.3 Operating Values and Limits ············································································· 24

6.4 Alarm Action······································································································25

6.5 Prestart Valve Status ··························································································28

7. Maintenance 35

7 1 Periodic Operation Inspection and Tests····························································35

E K C 0 0 3 1 0 2 - a

4 of 38

This page Intentionally Left Blank


137/806

This page Intentionally Left Blank

E K C 0 0 3 0 2 - a

5 of 38

1. Introduction

This manual is written to ensure safe handling of Stator Cooling Water System Before


138/806

This manual is written to ensure safe handling of Stator Cooling Water System. Before

operation, maintenance and inspection, be certain to read this manual for proper use of the

equipment. This manual should be kept near the equipment so it can be readily referenced.

2. Precautions for Safety

Signs and messages in this manual and on the equipment body are important for management,operation, maintenance and inspection. They are given to avoid possible injuries and damages as

well as to ensure correct handling of the equipment. The following signs and short messages

should thoroughly be understood before reading this manual. It is advised that you also read theinstruction manuals of related equipment and components.

IMPORTANT MESSAGES

Read this manual and follow its instructions. Signal words such as DANGER, WARNING, two kinds of CAUTION,and NOTE, will be followed by important safety information that must be carefully reviewed.

Indicates an imminently hazardous situation, which will result in death or serious injury if

you do not follow instructionsDANGER!

E K C 0 0 3 1 0 2 - a

6 of 38

APPLICATION


139/806



Unit.


situation arise which is not covered by this Toshiba Steam Turbine and Generator Manual, the matter should be

referred to Toshiba (contact details are specified at page 2 of this Manual)




RESULT FROM ANY FAILURE TO OBSERVE THE PROCEDURES,

INSTRUCTIONS, WARNINGS, DESCRIPTIONS, DATA AND INFORMATION


140/806

E K C 0 0 3 1 0 2 - a

8 of 38

SAFETY SIGN


141/806






E K C 0 0 3 0 2 - a

9 of 38

P i t t d i th t t h i l d It i i d t

ARNING!


142/806

■ Pump is not operated in the state where is no load. It is required to

pour in water before operating.

Pump is damaged.

■ Second alarm point (9.9ƒÊ

S/cm) is very dangerous.

This value indicates the maximum permissible conductivity.

If the conductivity has been reached this point, the generator shouldbe tripped.

■ The Generator can be run without the Stator Water system in

operation but output is then limited to 185,000kVA at 0.85pf.

■ If Stator Water conductivity reaches the second alarm point of 9.9ƒÊ

S/cm, the generator should be tripped immediately.

■ The second alarm contact is set at 9.9ƒÊS/cm, which indicates the

maximum permissible conductivity.

If the conductivity has been reached this point, the generator should

E K C 0 0 3 1 0 2 - a

10 of 38

O t ft ki ll th d f i d l i

CAUTION!


143/806

■ Operate a pump after making small the degree of opening and closing

of a pressure regulating valve.

It becomes the cause which an excessive pressure joins a stator coil and damage produces.

■ Make into 60• Ž

or less temperature of the cooling water which flows

to deionizer.

If temperature exceeds 60•Ž the performance will fall.

■ Do not freeze resin.

Effect will be lost once resin is frozen.

■ When not using deionizer, pure water is kept in the state of full of

water in a tub.

Dryness of resin reduces the performance.

■ When a stator water pump is started, don’t stand by it. Check the

water level of the storage tank after pump operating. If the water

level goes on decreasing the pump must be stopped at once The

E K C 0 0 3 0 2 - a

11 of 38

CAUTION


144/806

■ Set up the no fire zone near the hydrogen vent discharge pipe above

the roof. Check the existence of water at a “U” seal pipe of the vent

pipe near the storage tank.

If water does not exist in “U” seal pipe, hydrogen gas may be spread in a building and a fire and explosion

may occur. Moreover air flows into the tank and degrades the electrical conductivity of cooling water.

■ When the differential pressure increases to 0.09MPa, must be replace

the filter elements.

Only use manufacturer recommended filter elements.

■ Keep the following matters, when you exchange filters.

‡ Filter element exchanges total.‡AWash a filter

‡B

Air vent valve is opened, and water is poured into the tub,

extracting the air contained in the filter. Then drain valve is

opened and water is discharged.

E K C 0 0 3 1 0 2 - a

12 of 38

■ Since make up water could initially contain metal oxides etc it

NOTE


145/806

■ Since make-up water could initially contain metal oxides, etc., it

should be drained until clear before being fed through the filter to the

storage tank.

■ The amberlite IRN-150 is based on the resin being of the gel type and

having a matrix structure of styrene-divinyl benzene, and contains

copper.When you abolish it, please follow your regulations.

E K C 0 0 3 0 2 - a

13 of 38

3. Scope

This manual describes the method of operate the stator cooling water systems of the watercooled turbine generator


146/806

cooled turbine generator.

4. Related Documents

Refer to the Diagram of Stator Cooling Water System : 1KC003727.

5. Description

5.1 Design Data

Stator cooling water pump : 2920rpm, 1200 /min

Stator cooling water pump motor : 2920rpm, 30kW

Stator cooling water

Rated inlet pressure : Higher than 0.16MPa

Low inlet pressure alarm : set at site at equivalent flow rate 880 /min

x0MKF40CP104 (at x0MKF30AA851 Valve)

E K C 0 0 3 1 0 2 - a

14 of 38

5.2 General Description


147/806

5.2.1 Outline of Stator Winding Cooling Water System

Stator winding cooling system is designed to maintain temperature rise of the stator winding

suitably, and conductivity of the cooling water low. The cooling water to be supplied to stator

winding is held at rated flow under the conditions that the inlet temperature is 46• Žand the

conductivity at 25• Žis below 0.5ƒÊS/cm.

The flow rate and conductivity of the cooling water for stator winding is inspected and adjusted

by the control system consisting of stator water storage tank, two stator cooling water circulating

pumps, two stator water coolers, temperature and pressure control valves, stator water filter,

demineralizing equipment and instruments. There is a branch, bypassing the generator, with a

deionizer for keeping continuous purification of the water.

5.2.2 Stator Water Storage TankThe storage tank has a capacity of approximately 2.69m

3, and the water level is continuously

monitored by float switch which provides alarm when water level fluctuates above or below the

normal level. It also has a water level gauge so its water level can be observed with the naked eye.

Make-up water will be replenished to the deionizer through a filter so as not to increase

E K C 0 0 3 0 2 - a

15 of 38

5.2.3 Stator Cooling Water Circulating Pump

The cooling water circulation in normally performed by an A.C. motor-driven centrifugal pump.

In addition, an A.C. motor-driven centrifugal pump of equal capacity is installed as standby. The


148/806

pump can be started manually, and it can also be started automatically by a pressure switch

(x0MKF40CP105, x0MKF40CP106) located on the outlet pipe common to both pumps.

The rate of flow circulating through the deionizer is approximately 10% of that flowing through

the generator winding.

In order to remove either pump for inspection during one pump operation, valves are provided at

both inlet and outlet of each pump.

■ Pump is not operated in the state where is no load. It is required to

pour in water before operating.

Pump is damaged.

ARNING!

CAUTION!

E K C 0 0 3 1 0 2 - a

16 of 38

5.2.5 Stator Water Filter and Strainer

In the cooling water system, depth type disposable wound cartridge filters are provided at the

stator cooling water pump discharge to filter all the water to the generator winding.


149/806

These filters are designed to prevent metallic corrosive particles generated in winding and

piping from entering into winding hollow conductor. The minimum size of grains to be filtered by

the filters is about 3ƒÊm. A differential pressure gauge (x0MKF20CP101) is provided across

filter for observation of any solid substance which is accumulated.

■ When the differential pressure increases to 0.09MPa, must be replace

the filter elements.

Only use manufacturer recommended filter elements.

■ Keep the following matters, when you exchange filters.

‡ Exchange all Filter elements.

‡A

Wash a filter

‡BAir vent valve is opened, and water is poured into the tub,

extracting the air contained in the filter. Then drain valve is

opened and water is discharged.

CAUTION

E K C 0 0 3 0 2 - a

17 of 38

5.2.6 Deionizer

The deionizer is an ion exchange resin tower of floor type where the amberlite IRN-150 resin

(cathion exchange resin IRN-77 and anion exchange resin IRN-78 are mixed) are filled in


150/806

stainless steel wire-netting supporting the resin layers in a stainless steel tower. A pipe is provided

for replacing and removing resin from the deionizer.

■ Make into 60• Žor less temperature of the cooling water which flowsto deionizer.

If temperature exceeds 60•Ž the performance will fall.

■ Do not freeze resin.

Effect will be lost once resin is frozen.

■ When not using deionizer, pure water is kept in the state of full of

water in a tub.

Dryness of resin reduces the performance.

CAUTION!

E K C 0 0 3 1 0 2 - a

18 of 38

The quantity of water flowing into the deionizer can be inspected by a flow meter, but it should

not exceed 15% of the flow running to the generator winding. When the amount of water flowing

into the deionizer reaches this flow rate, and the conductivity of the generator inlet cooling water

can not be held under 0.5ƒÊS/cm, it is necessary to replace the ion exchange resin.


151/806

5.2.7 Cooling Water Conductivity

Each of the three conductivity measurements are temperature compensated to 25• Ž, and the

conductivity is measured by a conductivity indicator at the three points (the generator cooling

water inlet, the generator outlet and the deionizer outlet) in the cooling water system.

The conductivity indicator will successively indicate and has two alarm contacts in case of high

conductivity. Conductivity measuring elements are attached to above three points, and are so

arranged that they can be removed without taking the plant out of service.

5.2.7.1 Make-up Water to System

ALL make-up water for cooling water system is sent through filters and deionizer.

Fl shing sho ld caref ll be applied to the filter piping if feed ater

CAUTION

E K C 0 0 3 0 2 - a

19 of 38

5.2.7.2 Operation without Stator Cooling Water Flow

During normal operation, it is expected that the conductivity will be less than 0.5ƒÊS/cm. One

alarm contact is set at this value to anticipate any subsequent increase in conductivity and to

i ki i


152/806

permit making necessary corrections.

■ The second alarm contact is set at 9.9ƒÊ

S/cm, which indicates the

maximum permissible conductivity.

If the conductivity has been reached this point, the generator should

be tripped.

5.2.8 Alarm and Reduction of Generator Output with Turbine Interlock

5.2.8.1 Alarm

Item Alarm setting value

Generator inlet cooling water

press.( x0MKF40CP104

at x0MKF30AA851 VALVE)

LowSet pressure valve at equivalent flow rate

880 /min at site.

ARNING!

E K C 0 0 3 1 0 2 - a

20 of 38

5.2.8.1 Trip

Item Alarm setting value

Generator outlet cooling water temperature

(x0MKF20CT001 CT002 CT003)High 95• Ž


153/806

(x0MKF20CT001, CT002, CT003)g

Generator inlet cooling water pressure.

(x0MKF40CP101, CP102, CP103)Reduced

Set pressure valve at equivalent flow rate

720 /min at site.

5.2.9 Stator Winding Cooling Water Controlling Equipment

This equipment consists of stator water tank, stator water pumps, stator water coolers, statorwater filter, regulating valves, deionizer, and related piping and valves which are perfectly

installed on the base.

Refer to outline stator cooling water unit : Drawing No.1KC003760.

E K C 0 0 3 0 2 - a

21 of 38

6. Operation

6.1 Introduction


154/806

In the procedures below, the terms Stator Water and Cooling Water are used to distinguish

between the treated and untreated water, respectively.

■ The Generator can be run without the Stator Water system in

operation but output is then limited to 185,000kVA at 0.85pf.

During normal (weekend) shutdown, the Stator Water system is kept running to maintain water

conductivity.

The Stator Water interlock should not be canceled before tripping the unit since shutdown offers

the opportunity to check that Stator Water pumps trip with the generator. Immediately aftertripping, however, the interlock should be canceled and the Stator Water pump restarted.

6.1.1 Charging the Stator Water System

ARNING!

E K C 0 0 3 1 0 2 - a

22 of 38

6.1.2 Coolers

Each Stator Water cooler is rated at 100%.

As being filled, the coolers are filled first with Cooling Water and then Stator Water. As being


155/806

shut down for an extended period, they are drained of cooling water.

Prior to a cold start, the Cooling Water flow is shut off to allow the Stator Water temperature to

increase (due to friction losses).

6.1.3 Deionizer

■ If Stator Water conductivity reaches the second alarm point of 9.9ƒÊ

S/cm, the generator should be tripped immediately.

Deionizer resin has a life of about one year. It is replaced if:

a. The pressure drop across the deionizer exceed 1bar.

b. Stator water conductivity at its outlet exceeds

0.5ƒÊS/cm (with the normal proportion of Stator Water by-passing the coolers).

ARNING!

E K C 0 0 3 0 2 - a

23 of 38

6.1.4 Pump Testing on Load

Auto starting of the Stator Water standby pump is tested without stopping the duty pump.


156/806

6.2 Operating Procedure

6.2.1 Preparation for Starting

a. Set up the system as in the prestart valve status.

b. Check electrical supplies to motors.

c. Check alarm and protection supplies.

d. Check that air supply is available to proportioning valve.

e. Check that conductivity meters are in service.

f. Check that Stator Water pump bearing lubricating oil levels at the bearing oil gauge.

6.2.2 Charging and Starting the System

g. Start the duty pump, and set the standby pump to AUTO.

h. Trip the duty pump, confirm starting of standby pump automatically.

E K C 0 0 3 1 0 2 - a

24 of 38

q. Check that the pump discharge pressure returns to normal value(0.74MPa).

r. Set the standby pump to AUTO.

6 3 Operating Values and Limits


157/806

6.3 Operating Values and Limits

Item Unit Normal Alarm Trip

Stator water temperature

Generator inlet

Generator outlet

• Ž

• Ž

40 to 46

*76

48

10 above measured

outlet temp. at full

load

95

Storage tank level mm

Gauge glass

indication Normal• }

100

Stator water conductivity

Generator outlet

Generator inletƒÊS/cm less than 0.3

(1st) (2nd)

0.5 9.9 •

E K C 0 0 3 0 2 - a

25 of 38

6.4 Alarm Action

Alarm conditions Possible causes Action required

Stator

cooling water

LOW Failure of stator water

pump and motor

Check the stator water

pump and motor


158/806

cooling water

inlet pressure

pump and motor

Failure of press. switch

pump and motor.

Check the discharge

pressure gauge, standby

stator water pump will be

started.

Statorcooling water

inlet flow

LOW Failure of stator water pump and motor

Failure of press. Regulating

valve (x0MKF20AA103)

Leakage of water inlet line

Above action is required.

Check the pressure

regulating valve and

control sequence.

Check the leakage point.

Stator

cooling water

pump discharge

pressure

LOW Failure of stator water

pump and motor

Failure of press. switch

Check the failed pump and

motor.

Check the pressure gauge

and switches.

E K C 0 0 3 1 0 2 - a

26 of 38


Statorcooling water outlet

t t

HIGH Failure of regulating valve(x0MKF20AA101)

Check the generatorloading, stator water inlet

fl d


159/806

temperature flow and pressure.

Check the stator coil

temperatures with R.T.D

If necessary, detail check is

required with outlet water

temperature of each stator

coil.

Water level

in water storage

tank

HIGH

LOW

(Normal level• }100mm)

Failure of water level

switch

Leakage of storage tank

and piping

Check the water level

gauge with storage tank.

Normally, the water level is

decreased, because theevaporating steam of the

discharge water is vented

out through the vent

piping.

E K C 0 0 3 0 2 - a

27 of 38


Turbine interlock Without circulation

through the stator cooling

water system

The quality of the cooling

water will deteriorate and

conductivity will increase


160/806

Failure of both stator water

pump

Failure of regulating valves

Failure of stator water

coolers.

The rate of deterioration

may be influenced by

several factors and

following parameters have

been established by test.

Following reduction in

output to rated capability

without stator cooling

water circulation.

1) If the conductivity prior to

cessation of flow is more

than 0.5ƒÊS/cm within 3

minutes, reduce

voltage to zero and trip.

2) If the conductivity prior to

cessation of flow is less than

0.5ƒÊS/cm within 60

E K C 0 0 3 1 0 2 - a

28 of 38

6.5 Prestart Valve Status

NOTE

1. O: Open C: Close T: Throttle A: Automatic S: Select


161/806

VALVE

NUM-

BER

VALVE NAMEPLATE INSCRIPTION

VALVE

POSI-

TION

CHECK

REM-

ARKS

x0MKF20AA001 SCWP(A) SUCTION ISOL VALVE O

x0MKF20AA003 SCWP(B) SUCTION ISOL VALVE O

x0MKF20AA851 SCWP(A) DRAIN VALVE C

x0MKF20AA852 SCWP(B) DRAIN VALVE C

x0MKF20AA801 SCWP(A) AIR VENT VALVE C

x0MKF20AA802 SCWP(B) AIR VENT VALVE C

x0MKF20AA701 SCWP(A) DISHC. NON RETURN VALVE O

x0MKF20AA702 SCWP(B) DISHC. NON RETURN VALVE O

0MKF20AA002 SCWP(A) DISHC GATE VALVE O

E K C 0 0 3 0 2 - a

29 of 38

VALVE

NUM-

BER


VALVE

POSI-

TION

CHECK

REM-

ARKS

0MKF20AA856


162/806

x0MKF20AA856

(For cooler B)COOLER (B) DRAIN VALVE C

x0MKF20AA101 TCV TEMP. CONTROL VALVE A

x0MKF20AA009 FILTER INLET ISOL VALVE O

x0MKF20AA013 FILTER OUTLET ISOL VALVE O

x0MKF20AA807 FILTER AIR VENT VALVE C

x0MKF20AA910 FILTER ISOL VALVE FOR PDI O

x0MKF20AA912 FILTER ISOL VALVE FOR PDI O

x0MKF20AA911 FILTER EQUALIZE VALVE FOR PDI C

x0MKF20AA867 FILTER DRAIN VAVLE C

E K C 0 0 3 1 0 2 - a

30 of 38

VALVE

NUM-

BER


VALVE

POSI-

TION

CHECK

REM-

ARKSx0MKF30AA851 GEN/STAT CLG WTR GAUGE VALVE C


163/806

x0MKF30AA903 GEN/STAT CLG WTR GAUGE VALVE O

x0MKF50AA001 GEN/SCW INL HDR BLOW VALVE C

x0MKF50AA002 GEN/SCW OTL HDR BLOW VALVE C

x0MKF20AA868 GEN OUT SAMPLING VALVE C

x0MKF20AA929 GEN OUT CDTY CELL ISOL VALVE O

x0MKF20AA926 STORAGE TANK LS ISOL VALVE O

x0MKF20AA927 STORAGE TANK LS ISOL VALVE O

x0MKF20AA866 STORAGE TANK LS DRAIN VALVE C

E K C 0 0 3 0 2 - a

31 of 38

VALVE

NUM-

BER


VALVE

POSI-

TION

CHECK

REM-

ARKSx0MKF20AA015 DEIONIZER INLET ISOL VALVE T


164/806

x0MKF20AA703 DEIONIZER INLET NON RETURN VALVE O

x0MKF20AA916 DEIONIZER INL PRESS ISOL VALVE O

x0MKF20AA018 DEIONIZER OTL ISOL VALVE O

x0MKF20AA808 DEIONIZER AIR VENT VALVE C

x0MKF20AA860 DEIONIZER INLET PRESS DRAIN VALVE C

x0MKF20AA861 DEIONIZER RESIN DRAIN VALVE C

x0MKF20AA917 DEIONIZER OTL PRESS ISOL VALVE O

x0MKF20AA862 DEIONIZER RESIN WASH VALVE C

x0MKF20AA919 DEIONIZER CDTY CELL ISOL VALVE O

x0MKF20AA867 STRAGE TANK DRAIN ISOL VALVE C

E K C 0 0 3 1 0 2 - a

32 of 38

VALVE

NUM-

BER


VALVE

POSI-

TION

CHECK

REM-

ARKSGEN. INLET STATOR COOLING WATER PRESS

x0MKF40CP104 ISOL VALVEO


165/806

x0MKF40CP104 ISOL VALVEx0MKF40AA004

GEN. INLET STATOR COOLING WATER PRESS

x0MKF40CP104 TEST VALVEC

GEN. INLET STATOR COOLING WATER PRESS.

x0MKF40CP101 PS ISOL VALVEO

x0MKF40AA001 GEN. INLET STATOR COOLING WATER PRESS.x0MKF40CP101 TEST VALVE

C


x0MKF40CP102 ISOL VALVEO

x0MKF40AA002 GEN. INLET STATOR COOLING WATER PRESS.



x0MKF40CP103 ISOL VALVE O

x0MKF40AA003 GEN. INLET STATOR COOLING WATER PRESS.


GEN. INLET STATOR COOLING WATER PRESS.O

E K C 0 0 3 0 2 - a

33 of 38

VALVE

NUM-

BER


VALVE

POSI-

TION

CHECK

REM-

ARKSGEN. INLET STATOR COOLING WATER FLOW

x0MKF40CF001 ISOL(L) VALVEO


166/806

( )

GEN. INLET STATOR COOLING WATER FLOW

x0MKF40CF001TEST VALVEC

x0MKF40AA009 GEN. INLET STATOR COOLING WATER