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JSC ELECTROSILA

HYDROGEN COOLING SYSTEMOF TBB-200-2T3 TURBOGENERATOR

Operation Instruction Manual

0.467.489

Saint Petersburg2001

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CONTENTS

1. INTRODUCTION.............................................................................4

2. APPLICATION................................................................................4

3. SYSTEM COMPOSITION...............................................................4

4. SYSTEM ARRANGEMENT AND OPERATION...............................5

5. INSTRUMENTATION....................................................................11

6. ARRANGEMENT AND MOUNTING............................................. 12

7. INSPECTION OF THE COOLING SYSTEM COMPONENTS........15

8. SAFETY PRECAUTIONS..............................................................17

9. MAJOR OPERATING RULES........................................................21

10. PREPARATION FOR OPERATION...............................................18

POSSIBLE TROUBLES AND METHODS OFTHEIR ELIMINATION...................................................................22

12. STORAGE AND TRANSPORTATION RULES..............................24

Figure 1.

Turbogenerator shaft seals oil supply systemprinciple diagram..............................................................................25

Figure 2.

Turbogenerator -200-23 gas supply systemprinciple diagram..............................................................................26

Figure 3.

Turbogenerator -200-23 gas supply systemprinciple diagram..............................................................................27

Figure 4.

Electric pumping unit with AC motor.............................................28

Figure 5.

Electric pumping unit with DC motor.............................................29

Figure 6.

Oil cooler.............................................................................................30

0.467.489 Rev Sheet Docum Signature Date

DesignedHydrogen Cooling System

of turbogenerator -200-2T3

Operation instruction manual

Alt. Sheet Total

2 45

Inspector

Approved

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Figure 7.

Gauze filter.........................................................................................31

Figure 8.

Magnetic filter...................................................................................32

Figure 9.

Pressure regulator............................................................................33

Figure 10.

Balance tank......................................................................................34

Figure 11.

Hydraulic seal....................................................................................35

Figure 12.

Oil trap................................................................................................36

Figure 13.

Centrifugal fan...................................................................................37

Figure 14.

Oil control branch pipe.....................................................................38

Figure 15.

Sight branch pipe..............................................................................39

Figure 16.

Evaporator..........................................................................................40

Figure 17.

Gas control panel..............................................................................41

Figure 18.

Starting oil pump panel...................................................................42

Figure 19.

Position of valves of the gas supply system when operating

at transients and with the system filled with hydrogen............43

Appendix (reference).

List of components for Figure 1..............................................44

Appendix (reference).

List of components for Figure 2 and 3...................................45

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Rev. Sheet Docum Sign. Date

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1. INTRODUCTION

The present Operation Instruction Manual is intended for the attendantpersonnel to make familiar with the construction of hydrogen cooling systemfor turbogenerator of TBB-200-2T3 type as well as with the rules of itsoperation and maintenance.

2. APPLICATION

The turbogenerator hydrogen cooling system (hereinafter referred to asthe system) is designed to ensure the turbogenerator operation incompliance with its rated data (See the Turbogenerator Operation InstructionManual).

3. SYSTEM COMPOSITION

3.1. The turbogenerator hydrogen cooling system consists of thefollowing major units:

electric pumping units;

hydraulic seal;

oil coolers;

gauze and magnetic filters;

gas control panel;

centrifugal fans; refrigerating units;

evaporating devices (hereinafter referred to the evaporator);

balance tank;

pressure regulator;

oil trap;

instrumentation and piping valves.

3.2. Supplied together with the system are the spare parts listed in theList of spare parts, tools and accessories included into the set of servicedocuments.

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4. SYSTEM ARRANGEMENT AND OPERATION

The principle diagrams of hydrogen cooling system are shown in theFigures 1, 2 and 3.

4.1. The turbogenerator shaft seals oil supply system.

To prevent the hydrogen escape from the generator housing, the ring-type oil seals are used on the rotor shaft. The seal oil under the pressureexceeding the pressure of hydrogen in the generator housing enters theclearance between the seal bush and rotor shaft and forms the continuousfilm preventing hydrogen escape from the generator. The greater part of oil,which has passed through the seals, is drained to the air side and only thelesser part to the hydrogen side.

To supply oil to the seals from the turbine oil tank, the use in the systemis made of the oil pumps: P1 operating pump, P2 standby pump and P3

emergency pump. Pumps P1 and P2 are equipped with AC electric motors,while pump P3 with DC electric motor.

The suction piping of the oil pumps are connected with the cleancompartment of the turbine oil tank. One of the oil pumps is continuously inoperation. The automatic starting up of the standby and emergency oilpumps is accomplished on a pulse from the pressure transducers PS1 andPS2 installed on the pressure piping downstream the oil filters.

When the electric motor of the operating pump P1 is out of operation orwhen the pressure in the pressure piping dropped by 0.15 MPa of the rated

pressure specified during the system adjustment, the standby oil pump P2comes into operation on a pulse from the first pressure transducer PS1.When the oil pressure drops by 0.25 MPa of the rated value or when both oilpumps are out of operation, the emergency oil pump P3 comes intooperation on a pulse from the second pressure transducer PS2. Theinterruption in the electric pumping units power supply shall not exceed 20 s.

From the oil pumps the oil is delivered to the oil coolers OC1 (OC2).Either one of the oil coolers or both oil coolers connected betweenthemselves in series or in parallel may be in operation.

After the oil coolers, mechanical cleaning filter F1 (F2), magnetic filterF the oil under the specified pressure the value of which is maintained withthe help of pressure regulator PR, via the balance tank DT enters the annularclearance between the generator shaft and seal bushes.

Provision is made in the diagram for the installation of the balance tank.When changing-over from one oil pump to the other and during the short-term malfunctions in the oil supply system due to the cessation of oil supplyfrom the oil pumps, the oil from the balance tank is supplied to the generatorshaft seals. The pressure of oil, which is in this case is supplied to the shaft

seals, is specified by both the height of the balance tank installation and thepressure of gas in the generator housing.

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To control visually the oil pressure for each pump, the circuit providesfor the pressure gauges PG6PG8 at the pressure mains as well as thecompound pressure-vacuum gauges VPG1VPG3 at the suction mains.

Furthermore, installed in the oil supply system are the pressure gaugesfor measuring the oil at the PG4 inlet and PG3 outlet from the pressureregulators as well as the pressure gauges PG1 and PG5 on the shaft seals.

To control the oil-to-hydrogen pressure drop value with the emergencydrop signal output to the unit control board, the Designer shall provide forthe installation of the pressure drop transducer.

When passing through the seals, the oil comes in contact with the airand hydrogen and is capable of absorbing these gases as well as to evolvethem when flowing along the pipings. The large cross section of the drainpipings and oil header contribute to the hydrogen and air to evolve from theoil.

The gas volumes of the drain oil header and drain oil pipings areventilated by means of centrifugal fan CF1. The exhaust piping of this fan iscut into the exhaust pipe DN150 brought out to the roof of the TPSpowerhouse. The check valve CV1 preventing the possibility of gascirculation from the exhaust pipe DN150 to the drain header is mounted onthe exhaust pipe. The gas volume of the turbine oil tank is vented by meansof fan CF2. To avoid the accumulation of explosive mixture in any of theabove mentioned gas volumes, the fans shall be continuously in operation.

Upstream the fan CF1 installed is the oil trap OT, which is the tank

inside which the lateral tapered partitions are fitted. The oil vapours settle onthe partitions, the oil accumulates in the lower part of the oil trap and isdrained outwards via the drainage cock.

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temperature detectors RTD1 and RTD2 for gas temperature control in orderto regulate the hydrogen flow rate through the evaporator and to choose theoptimum duty of the installation operation are placed at the hydrogen inletto and outlet from the evaporator. The hydrogen flow rate through theevaporator is controlled by the valve, while the refrigerating unit operationduty is chosen by adjusting the thermoregulating valve TRV. Thetemperature of hydrogen leaving the evaporator shall be within 0 to +10 0C.The water is drained from the evaporator once 24 hours.

When the temperature of hydrogen leaving the evaporator is higherthan +10 0C, the refrigerating unit shall be disconnected from the system,having shutoff the valves at the inlet and outlet, for the evaporator thawing.

To drain the liquid (water or oil) in case of its penetration into thegenerator housing and terminal box, provision is made in the circuit for thedrainage pipelines, one of which is connected to the lower point of thecarbon dioxide header, while two other pipelines are brought out of the

stator outer shields. The level detectors giving the relevant signal about theliquid penetration into the generator housing to the unit control board areinstalled in the lower points of the above mentioned pipelines. To visuallycontrol the presence of liquid in the drainage pipelines, the sight branchpipes are installed in the drainage pipelines.

The hydrogen purity in the turbogenerator housing is controlled bymeans of the automatic gas analyzer mounted on the gas control panel.

From the generator housing the analyzed gas mixture, passing alongthe piping via the pressure reducer PR, fine-adjustment valve PRV and flow

rate indicator FRI, enters the gas analyzer GA1, and having passed throughthe gas analyzer is vented to the atmosphere. The discharge to theatmosphere of the spent hydrogen sample as well as of the gas from thegenerator housing during transients shall be accomplished into the specialvent duct separated from the housing common ventilation.

During the generator operation and short-term shutdowns the puritycontrol of hydrogen inside the turbogenerator housing may be accomplishedby means of chemical analysis.

The leaks of hydrogen in the current leads enclosure, in the neutral-terminal box, in drain chambers of the shaft seals from the air side, in thenoise-protection enclosure as well as in the stator winding water coolingsystem are performed with the help of stationary gas analyzers. The gasanalyzers are installed in the vicinity of the generator. Each gas analyzerautomatically samples the gas mixture for analysis alternatively from fourpoints.

The separators are mounted to catch the oil vapours from the gassampled for analysis from the drain chambers of the shaft seals on the airside.

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4.3. Signalling.

To signal the failures in the generator hydrogen cooling system, theprovision shall be made on the unit control board (UCB) by the Designorganization for the operation of the following light-audible signals receivedfrom the signalling instruments and devices:

abnormal oil-to-hydrogen pressure drop;

low oil level in the balance tank;

emergency oil level in the balance tank;

low pressure of cooling water;

abnormal hydrogen pressure;

high oil level in the hydraulic seal;

low oil level in the hydraulic seal; low hydrogen purity;

high content of hydrogen in the air;

liquid in the generator housing;

centrifugal fan emergency shutdown;

gas coolers pumps emergency shutdown;

oil pump emergency shutdown;

automatic starting up of the standby pumps of gas coolers;

automatic starting up of the standby oil pumps.

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5. INSTRUMENTATION

5.1. The pressure gauges control the pressure of oil in the shaft seal oilsupply system. The oil pressure at the suction pipings of the oil pumps iscontrolled by the compound pressure and vacuum gauges.

5.2. The pressure of gas in the generator housing both duringoperation and at transients is controlled by the pressure gauges mounted atthe gas control panel.

5.3. The pressure of hydrogen in the generator housing isautomatically controlled by the pressure transducer PS.

5.4. The purity of hydrogen inside the generator housing, with theannunciation of the parameter limit value, is automatically controlled by thegas analyzer installed at the gas control panel.

5.5. The annunciation about the limit levels of oil in the hydraulic sealand balance tank as well as about the presence of liquid in the generatorhousing is performed by the level transducers-relays the primary sensor ofwhich is installed at the pipings or components, while the transmittingtransducer at the unit control board panel.

5.6. The content of hydrogen in the enclosures of the shielded currentleads, in the shaft seal sumps on the generator air side, in the neutral-terminal box, in the noise-protection enclosure, in the stator winding watercooling system is controlled by means of stationary gas analyzers.

5.7. The temperature of oil leaving the oil coolers and at the oil inlet tothe seals is controlled with the aid of the resistance temperature detectors.

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6. ARRANGEMENT AND MOUNTING

6.1. The generator hydrogen cooling system components are arrangedin conformity with the Design organization technical documents worked outaccording to the requirements described in the present Operation InstructionManual.

6.2. The gas pipings and oil pipings shall be mounted in full conformitywith the factory drawings.

6.3. An easy access for the mounted gas piping examination andrepair shall be provided for.

6.4. All the piping of the gas system as well as of the turbogeneratorshaft seal oil supply system shall be made of the steel seamless pipes andshall be reliably fastened.

6.5. During mounting the connection of the gas piping shall beperformed by welding; where possible, the flange connections shall beexcluded. The number of flange connections in the generator shaft seal oilsupply system shall be minimum and shall be defined from the possibility ofcontrolling the pipes inner surface cleanness as well as of conducting theinspection and repair on the equipment mounted on these piping. Thebosses and pipe unions for the instruments shall be cut into the previouslyassembled oil piping. The welded joints of the previously cleaned pipes shallbe made with the argon-arc welding without backing rings. No cuttings-inand welding-in on the assembled piping are allowed to be performed.

6.6. After the preliminary assembly the oil piping shall bedisassembled, cleaned and handed over to the chemical shop, with theflanges plugged.

6.7. All the portions of the drain piping shall have no loop configurationand shall be sloped by 20 as minimum in the direction of drain.

6.8. When the oil supply system operates with the use of turbine oil,the flange connections on the pressure piping shall be packed with the oil-and benzine-resistant rubber gaskets 2.0 mm in thickness, while on the drain

piping with the oil- and benzine-resistant rubber gaskets 2 mm to 3 mm inthickness.

6.9. When cleaned and accepted by the chemical shop, the pressurepiping shall be assembled and tested with turbine oil at a pressure of1.6MPa applied for 30 minutes. The level transducers-relays shall bedisconnected. Initially test the drain oil piping of the shaft seals oil supplysystem for leakproofness with a pressure of0.8 MPa applied for 30 minutes.There shall be no leaks in the oil piping.

6.10.Prior to assembly clean all the gas piping by purging them with

steam or dry compressed air.

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6.11.The flange connections of the gas piping are packed with a oil-and benzine-resistant rubber 2 mm to 3 mm in thickness.

6.12.All the portions of the gas system shall have no loop configurationand shall be sloped by 2 as minimum to provide the drain of liquid whichmay be condensed in the pipes via the drain valves installed in the lowestpoints of the gas piping. If you cant avoid the loop configuration of thepiping (as for example, when laying the pipes to the gas control panel), thedrain valves shall be placed on these piping loops and shall be arranged inthe places with an easy access for maintenance.

6.13.Prior to installing, all the valves of the gas system are tested forleakproofness with an air pressure of0.8 MPa, being submerged into water.If there is no air leak, the valves are considered to be gas-tight. The housing,the sump and the sealing surface of the valve shall be subjected to the test.All the valves shall be mounted in the places accessible for maintenance andinspection during operation.

6.14.When the mounting of the gas system is over, the system istested for leakproofness with an air pressure of0.8 MPa; in doing so, thegenerator housing with the carbon dioxide header as well as the pulse tubesof the instruments are disconnected and the hydrogen and carbon dioxidelines, the drain piping and evaporating devices shall be joined by means oftemporary jumpers. In this case the leaks are located with the help of soapsolution or haloid leak detector. The gas system is considered to be leak-proof if at an air pressure of0.8 MPa the pressure drop in the system duringone (1) hour does not exceed 0.66 kPa.

6.15.Perform the gas leakage test of the instrument pulse tubesseparately from the gas system. The requirements for the gas tightness ofthe above mentioned tubes are the same as for the rest of the gas-systemgas piping. The gas leakage test of the carbon dioxide header is conductedduring the stator casing pressure test or in the course of the final leakagetest on the whole generator together with the gas-oil system.

6.16. Install the oil pressure drop regulators strictly vertically at thegenerator elevation in order to exclude slide valve friction in the box.

6.17.Cut the pipe DN20, connecting the piping DN25 of the regulatorsPR gas feedback with the seal oil drain piping DN65 at the exciter end, intothe upper part of the piping DN65 horizontal portion in the vicinity of thegenerator shaft seal.

6.18.Mount the balance tank along row A opposite the generator. Thepiping running between the balance tank and the generator shaft seals shallbe as short as possible. The platform for maintenance shall be done near thebalance tank.

6.19.Set the primary transducers of the level detectors LS2, LS4 so that

the level of the detectors operation is 60 mm to 70 mm lower than the upperedge of the balance tank housing.

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6.20.For ease of operation, arrange the valves V5, V13, V21, V29, V30and pressure gauges PG3, PG4 in the immediate vicinity of the pressureregulator.

6.21.Place the pressure gauges PG1, PG2 on the pressure piping at alength of no more than 1 m from the seal body after the insulating branchpipe.

6.22.Mount the oil pumps in the immediate vicinity of the oil tank. Thesuction piping shall be as short as possible and shall have minor number ofelbow pipes. The abrupt changes in cross sections as well as the sharp elbowpipes are not admitted.

6.23.Connect the suction pipes of the oil pumps to the cleancompartment of the oil tank.

6.24.Drain the oil from the hydraulic seal of the oil pump gland into theturbine oil tank using the pipe of at least DN20.

6.25.Valves V3 and V4 are used to purge the gas volume of the shaftseals.

6.26. Install the pipes DN80 running from the fans CF1 and CF2 in theexhaust pipes DN150 so that the axis of the pipe DN80 end part and the axisof the exhaust pipe DN150 are in coincidence.

6.27. Install the oil filters in the immediate vicinity of the pressure

regulator.

6.28. Install the oil control branch pipes at the generator elevation. Forease of inspection, the branch pipes shall be fitted out with the electricillumination made with the use of lamps of explosion-proof design.

6.29.Weld the flanges of the level detector-relay primary transducerseparately from the housing of the transducers, having ensured thedeviation from their alignment to be no more than 1 mm.

6.30.Perform the gas sampling for the chemical analysis as well as formeasuring the humidity through the valves V8, V9, V33, V34 (see Figure 2,3).

6.31.When performing the filling-in and during the system operationwith the use of hydrogen, the visible break (air gap) on the air supply line inthe gas control panel shall be made by withdrawing the removable jumper.

6.32.Arrange the refrigerating units in the immediate vicinity of thegenerator (at a distance of no more than 6 m) in the place not subject tovibration. Using the thermal insulation, insulate the evaporating devices and

the parts of hydrogen pipes connected to it at a length of1 m.

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7. INSPECTION OF THE COOLING SYSTEM COMPONENTS

When mounting or during the overhaul the following components of thecooling system shall be subject to inspection:

electric pumping units;

shutoff valves; balance tank;

float-type hydraulic seal;

oil and magnetic filters;

pressure regulator;

oil coolers.

7.1. The electric pumping units are inspected in compliance withmanufacturing-plant Instruction Manual.

7.2. The shutoff valves of the oil piping shall be inspected in thefollowing order:

unscrew the bolts and remove the valve cover;

check the connection of the slide valve with the valve stem; the slidevalve shall be reliably connected with the valve stem;

remove the dirt, rust and foreign matter from the valve housing;

assemble the valves and install them vertically, and then in positionClosed fill them with kerosine from the inlet side.

Note. The valve is considered to be fit for operation if the kerosine does

not penetrate into valve cavity from the outlet side.

7.3. When inspecting the balance tank, it is necessary:

to remove the covers on the access (inspection) hatches arranged onthe end parts of the tank bottom;

to check for the absence of foreign matter and dirt inside the tankhousing;

to install the covers into their places.

7.4. The inspection of the float-type hydraulic seal shall be conductedin the following sequence:

remove the float-type level regulator;

check the inside of the tank housing for the absence of rust andforeign matter;

withdraw the lock screw installed for the period of the hydraulic sealtransportation from the level regulator;

check manually the stroke (movement) of the lever with the floatfrom the extreme lower position to the upper position as well as fromthe upper position to the lower one, in doing so, the lever shall movefreely without binds.

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Note: Check the hydraulic seal for leakproofness when pressurizationthe generator.

7.5. The inspection of the oil filter shall be conducted in the followingsequence:

remove the cover, unlock the washers, unscrew the bolts andwithdraw the unit of filter elements;

disassemble the unit of filter elements for the separate filterelements;

wash the inner cavity of the housing, the cover and filter elementswith a washing solution of the following composition (per 1 l of water):50 g of caustic soda, 30 g of soda ash, 50 g of trisodium phosphate,50 g of water glass at a temperature of80 to 90 0C. Wash the filterelements using the hair brush. When the housing is washed with awashing solution, wash the cover and filter elements with hot water(80 to 90 0C) and purge them with dry compressed air;

assemble the unit of filter elements, check the tightening of the nutsin the unit of filter elements for tight fitting of the filter elements toeach other. The 0.02 mm feeler gauge shall not pass through in theplace where the inner casings of the filter elements fit each otheralong the whole circumference;

check the condition of the gaskets and fasteners;

assemble the filter as follows: install the unit of filter elements, placethe disc, screw up the bolts, lock them with washers, close the cover.

7.6. The inspection of the magnetic filter shall be conducted in thefollowing sequence:

remove the cover;

screw the eye-bolt into the tapped hole of the magnet-unit grid andwithdraw the magnet unit from the housing and then place it onto theclean nonmagnetoconductive surface (for example, onto the woodenboards);

screw out the eye-bolts, install the magnet unit with its magnetsupwards;

clean the surface of the magnets from the adhered ferromagneticparticles. It is necessary to bear in mind that the magnets in the

magnet unit are assembled so that each row of magnets has theunlike polarity;

install the cleaned magnet unit into the filter housing, install the filtercover.

7.7. Inspect the pressure regulators and oil coolers in compliance withthe Operation Instruction Manuals for the corresponding devices, includedinto the set of service documents.

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8. SAFETY PRECAUTIONS

8.1. At the electric power stations equipped with the hydrogen-cooledgenerators one should be guided by safety regulation applicable to thepower engineering.

8.2. The hazard of the explosive mixture formation may occur:

In the generator housing:

when there is no hydrogen purity control and at the severecontamination of hydrogen with air released from the oil;

when the generator is not completely purged with carbondioxide prior to its filling with hydrogen;

when hydrogen penetrates the generator filled with air (due tothe leaky valves at the gas control panel and when there is no visiblebreak in the hydrogen piping).

In the oil system equipment and pipes:

when hydrogen is contaminated with air released from the oil inthe hydraulic seal at the high flow rate of the seal oil to the hydrogenside, and when there are no purgings;

when air is contaminated with hydrogen released from the oil inthe drain oil pipes of the shaft seals, with no required ventilationavailable.

8.3. To avoid the formation of the explosive mixtures, one shouldstrictly observe the regulations on the generator gas-oil system operation.

8.4. During the generator operation check the content of hydrogen inthe generator shaft seal sumps at least once 24 hours. When hydrogen in thequantity of more than 1 % is detected to be present in these sumps, purgethem with carbon dioxide and eliminate the causes of the hydrogenpenetration.

8.5. The information on the other measurable quantity control is givenin the Generator Operation Instruction Manual.

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9. PREPARATION FOR OPERATION

9.1. Oil pumping in the oil supply system.

When the mounting or overhaul of the oil supply system is over, the oilpipes shall be pumped using the turbine oil. Prior to performing the pumping,it is necessary:

to disconnect the pipes from the generator shaft seals, balancetank, oil pressure regulator, oil coolers and hydraulic seal;

to install the temporary jumpers onto the disconnected ends ofthe pipes. In doing so, connect the pipes of the oil supply to thegenerator shaft seals with the drain pipes using the jumpers.

The requirements for the jumper inner surface cleanness are the sameas for the manufacture of the basic oil pipes. The pumping shall beperformed by alternately using all the pumps of the shaft seals oil supply

system. The oil temperature shall be at least 40 0C. The duration of the oilsystem pumping is at least 48 hours. The pressure of oil in the system duringpumping is at least 0.9 MPa.

The system is considered to be washed if the oil pressure drop acrossthe filters remains practically constant.

9.2. Prior to starting the generator it is necessary:

a) to test-operate the oil pumps;b) to test the reliable automatic starting up of the standby oil pumps;

Check the circuit of the automatic starting up of the generator shaftseals standby oil pumps for reliable operation in the following way:

stop the oil supply from the operating oil pump; in this case, thestandby oil pump comes into operation on a current signal from thepressure transducer;

by partially closing the valve on the pressure piping of theoperating pump reduce the pressure in the system up to a value ofthe operate current setting of the second pressure transducer; indoing so, the emergency oil pump comes into operation;

disconnect the power supply of the standby oil pump electric

motor, in doing so, the emergency oil pump comes into operation.

c) to check the operation of the whole signalling system;

To check the operation of the whole annunciation system:

check the signal High oil level in the hydraulic seal and signalLow oil level in the hydraulic seal by filling the oil into and drainingthe oil from the hydraulic seal;

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check the signal Liquid in the generator housing by filling thedrain piping with the level detector-relay mounted on it with turbineoil;

check the signals about the change of oil levels in the balancetank by emptying the tanks;

check the signal Oil pump emergency shutdown when

conducting the test operation of the circuit of automatic starting upof the standby oil pumps; check the signal Low purity of hydrogen in compliance withthe technical documents for the gas analyzer.

d) to adjust all the instruments of the system in compliance with theInstructions attached;

e) to adjust the oil pressure regulator.

Adjust the pressure regulator without sealing bearings, for whichpurpose it is necessary:

to disconnect the pressure oil piping portion running after thefeedback line of the regulator under adjustment and to install at thisportion the temporary jumper (flexible hose or steel pipeline) withthe valve and pressure gauge and to connect this jumper with thedrain oil piping; to place the temporary plugs with the gaskets on the pressure oilpiping at the exciter end, on the branch pipes of oil drain from theshaft seals to the hydraulic seal. Then the adjustment shall beperformed in compliance with the requirements of PressureRegulator Operation Instruction Manual included into the set ofservice documents.

9.3. Generator transfer to the hydrogen cooling and hydrogendisplacement.

The generator shall be transferred to the hydrogen cooling only whenthe generator together with the gas-oil system is tested for leakproofness.

The transfer to the hydrogen cooling shall be accomplished at thegenerator stopped or at the generator operating without excitation at no-load.

The hydrogen discharge under emergency shall be begun during thegenerator rundown.

The transients (the process of the generator transfer to the hydrogencooling or air) shall be performed at a pressure of gas inside the generatorwithin 0.015 to 0.02 .

Prior to beginning the transfer, provide the oil supply from the shaft sealvia the oil pressure regulator.

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a) Displacement of air from the system with carbon dioxide.

The system is filled with carbon dioxide from the central piping of thestation gas supply mains via the gas control panel. The pressure measuredby the pressure gauge mounted on the carbon dioxide header shall be nomore than 0.3 MPa. The air shall be vented to the atmosphere. Prior tosupplying the carbon dioxide to the generator, the compressed air supplypiping shall be disconnected, having thus made the visible break (air gap) inthis piping. The visible break in the piping of the hydrogen supply from thereceiver to the gas control panel shall be also made.

When performing the filling with carbon dioxide, the samples for thecarbon dioxide content shall be taken from the valve V8 mounted on thehydrogen header of the gas control panel. When taking the gas samplesfrom valve V8, valve V4 shall be closed.

The generator filling with carbon dioxide is considered to be completed

if the sample contains at least 85% of carbon dioxide.

b) Displacement of carbon dioxide from the system and filling thesystem with hydrogen.

The system is filled with hydrogen from the central piping of the stationmains, in doing so, the pressure upstream the valves at the inlet to the gascontrol panel shall not exceed 1.0 MPa measured by the pressure gaugemounted on the hydrogen header of the gas control panel.

From the beginning and till the end of the generator filling with

hydrogen the samples of gas shall be taken for chemical analysis in order todetermine its percentage from the valve V9 on the gas control panel, havingpreviously closed valve V5.

The displacement of carbon dioxide with hydrogen is considered to becompleted if the hydrogen percentage in the sample amounts to at least98%, whereupon the pressure of hydrogen in the generator housing shall beincreased to the rated one.

When the generator is filled with hydrogen, purge the gas volumes of

the float-type hydraulic seal, pulse lines of all pressure gauges, detectorsand gas analyzers.

The gas analyzer used to control the purity of hydrogen in the generatorhousing shall be switched on and the readings of this analyzer shall bechecked against the data of the sample taken for chemical analysis.

The position of the valves at transients is shown in Figure 19.

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10. MAJOR OPERATING RULES

10.1.The position of the valves during the generator operation with thesystem filled with hydrogen is shown in Figure 19.

10.2.The hydrogen inside the generator housing shall have the purityand humidity specified in the Generator Operation Instruction Manual.

10.3. If the purity of hydrogen inside the generator housing decreasedbelow 98%, the generator shall be purged with pure hydrogen. The purgingis accomplished manually by opening the valves on the line of hydrogensupply and on the line of gas discharge from the carbon dioxide supplyheader of the gas control panel.

10.4.Maintain the pressure of hydrogen inside the generator housingand the pressure of oil at the shaft seals in compliance with therequirements of Generator Operation Instruction Manual.

10.5.When the generator filled with hydrogen is in operation, make avisible break in the air supply piping.

When there is air inside the generator housing, the visible break shall bemade in the hydrogen supply line.

To meet these requirements, provision is made in the gas control panelfor the corresponding removable branch pipe.

10.6.Generator transfer from the hydrogen cooling to air.

At the generator scheduled stopping or at the failures requiring thegenerator stopping and opening, remove hydrogen from the generatorhousing and fill the housing with air. Perform this operation in the followingsequence:

a) When transferring the generator from the hydrogen cooling to air,displace hydrogen with carbon dioxide. In doing so, decrease the hydrogengauge pressure from the rated value to 0.0150.02 MPa. The rate of thegauge pressure decrease is no more than 0.1 MPa per hour, except for in an

emergency.

b) The process of hydrogen displacement with carbon dioxide shall besimilar to the process of air displacement described in it. 9.3.a. Thedisplacement is considered to be completed if the generator contains at least98% of carbon dioxide.

c) The carbon dioxide displacement shall be accomplished by thesupply of pure dry compressed air (with air relative humidity of no more than40%) to the generator. Take the samples for chemical analysis from thevalve V9 in the gas control panel (in doing so, valve V5 shall be closed). The

gas displacement is considered to be completed if the chemical analysisshows the total absence of carbon dioxide.

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11. POSSIBLE TROUBLES AND METHODSOF THEIR ELIMINATION

Table 11-1

Trouble Possible causeMethods of elimination

(remedy)

Decrease of hydrogen purity inthe generatorhousing.

Increased flow rate of oil inthe shaft seals to thehydrogen side.

Air inflow to the oil piping atthe pump suction line.

Purge the generator with freshhydrogen until the hydrogen purityis at least 98 %.

Eliminate the leaky places in the oilpiping at the pump suction line.

Drop of hydrogenpressure in thegenerator housing.

Failure of the gas systemleakproofness.

When in position Closed,the oil level regulator in thehydraulic seal is leaky.

Locate the gas leakage and tightenthe leaky place.

Close the valve V18 (Figure 1). Fillthe tank of the hydraulic seal withoil to the middle of the sight glassafter which half-open the valve V17,adjust the flow rate through thisvalve so that the oil level in thetank of the hydraulic seal remainedconstant. During the next shutdownof generator remove hydrogen,open the hydraulic seal andeliminate the trouble.

Emergency drop ofoil pressure in theseals, which resultsin the oil film break,in the bush babbittmelting out; lowlevel of oil in thebalance tank.

Failure in the shaft seal unitoperation.

Switch off the turbine overspeedgovernor, decrease immediatelythe hydrogen pressure and, notwaiting for the turbogenerator setto come to a full stop, begin thedisplacement of hydrogen from thegenerator housing. When thegenerator is transferred to air, openthe seal body and eliminate thetrouble.

Oil pumps failure.

When the generator is transferred

to air, find out and eliminate thecause of the oil pumps failure.

Liquid in thegenerator housing.

Failure in the shaft seal unitoperation (oil haspenetrated into thegenerator housing). See the method of the trouble

elimination in the TurbogeneratorOperation Instruction Manual.Failure of the leakproofness

of the gas cooler tubes(water has penetrated intothe generator housing).

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Table 11-1 (continued)

Trouble Possible causeMethods of elimination

(remedy)

Increase of oil level in

the hydraulic seal.

Failure of the level

regulator.

Put the standby hydraulic seal intooperation.

At the nearest possibility find andeliminate the hydraulic seal trouble.

The centrifugal fan isout of operation.

The electric motor powersupply circuit is open.

Eliminate the failure in the powersupply circuit of the faulty fanelectric motor.

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12. STORAGE AND TRANSPORTATION RULES

The storage, preservation, depreservation and transportation rules forthe system equipment are specified in the Instruction for Transportation andStorage of Electrical Machines and Equipment .458.000 included into aset of service documents.

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Appendix (reference)

List of components for Figure 1

Name Designation Q-ty Note

DTPS1, PS2HSV1V6V7V10V11V15V16V22V23V25V26V43

V44V46CCV1CV2CV5SV1PG1, PG2PG3PG4PG8VPG1VPG3

OC1, OC2OTP1, P2

P3

OCBP1, OCBP2SBP1SBP5PRLS1LS4RTD1RTD3OF1, OF2MF

CF1, CF2

Damper tankPressure sensor 0-1.6 Hydraulic sealBellows-sealed valve DN15Stop valve DN25Bellows-sealed valve DN25Stop valve DN50Bellows-sealed valve DN50Stop valve DN80

Stop valve DN150Pressure gauge cockCheck valveCheck valve DN80Special valvePressure gauge scale 0-600 Pressure gauge scale 0-1.0 Pressure gauge scale 0-1.6 Vacuum pressure gaugescale 100-0-300 Oil CoolerOil trapElectric pump unitwith AC motorElectric pump unitwith DC motorOil control branch pipeSight branch pipePressure regulatorLevel sensorResistance temperature detectorOil filterMagnetic filter

Centrifugal fan

1216457318

3131412153

212

1

2514321

2

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Appendix B(reference)

List of components for Figure 2 and 3

Name Designation Q-ty Note

SCU1SCU7PRVGA1

GA2,GA4

PS

E1, E2FRIV1, V2, V25,V45V47V3V6, V22V24,V26,V28V30V32, V37V48V51, V44V7V21, V27V33V36, V29V38V43CT1CT3

SVPG1, PG3PG2, PG4SD1SD3SBP1SBP3GD1GD3PRLS1LS3S1, S2

TV1, TV2RTD1RTD4RU1, RU2

Sample conditioning unitPrecise regulation valveGas analyzer

Gas analyzer

Pressure sensor 0-0.63

EvaporatorFlow rate indicatorBellows-sealed valve DN25

Bellows-sealed valve DN50

Bellows-sealed valve DN15

Condensate-tapper

Safety valvePressure gauge scale 0-1.0 Pressure gauge scale 0-1.6 Sample drierSight branch pipeGas distributorPressure regulatorLevel sensorSeparator

Thermoregulating valveResistance temperature detectorRefrigerating unit

711

3

1

216

18

27

3

122333132242

scale90-100% 2in airscale0-3%2 in air

H2 Cooling

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