mav lube oil system

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NUCLEAR POWER CORPORATION OF INDIA LIMITED (A GOVERNMENT OF INDIA ENTERPRISE) KUDANKULAM NUCLEAR POWER PROJECT NUCLEAR TRAINING CENTRE T RAINING M ANUAL O N TURBINE LUBRICATION SYSTEM (MAV) Document No: Rev number: 0 Next rev due on Prepared by Vivek Rathi Checked by Abid Hussain Issued By Suresh Kumar Revised by Rev date

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Page 1: MAV Lube Oil System

NUCLEAR POWER CORPORATION OF INDIA LIMITED

(A GOVERNMENT OF INDIA ENTERPRISE)

KUDANKULAM NUCLEAR POWER PROJECT

NUCLEAR TRAINING CENTRE

TRA IN ING MANUAL ON

TURBINE LUBRICATION SYSTEM

(MAV)

Document No:

Rev number:

0 Next rev due on

Prepared by

Vivek Rathi Checked by Abid Hussain

Issued By Suresh Kumar

Revised by

Rev date

Page 2: MAV Lube Oil System

CONTENTS

Sl No: Index Page No:

1. Introduction 1

2. System Description 1

3. List of Equipment 2

4. Normal Operation of the System 2

5. Operation Under Abnormal Conditions 2

6. Backup System Requirements 3

7. Technical Data 4

8. Power Supplies 4

9. Instrumentation 4

10. Alarms And Actions 6

11. Trouble Shooting 7

12. Hazards And Precautions 7

13. Maintenance 7

14. References 7

Page 3: MAV Lube Oil System

1. INTRODUCTION :

The turbine generator lubrication system (MAV) is intended:

To provide lubrication oil for turbine, generator and exciter bearings;

For turbine generator emergency oil supply during failure of normal power supply;

To prevent oil vapour egress from the oil tank and the bearing casings into the turbine hall.

2. DESCRIPTION OF THE SYSTEM :

To supply oil to the turbine bearing lubrication system, two pumps driven by AC motors and one emergency pump driven by D.C. motor are installed.

At normal operation one AC pump is running, the second pump is a stand-by.

Oil is supplied by one pump from the oil tank through the oil coolers into the pressure header and from the header - to the bearings. Upstream of the discharge header there is a pressure regulating valve which maintains pressure at the level of the turbine axis as 0.12 MPa. Due to short-term operation (less than 1 hour) the emergency oil pump supplies oil to the oil pipeline downstream of the pressure regulating valve, i.e. downstream of the oil coolers, in order to reduce electric motor power consumption and capacity of the battery.

After the bearings, oil flows by gravity to the discharge header and then into the oil tank. Cooling water is supplied to the oil coolers from the intermediate cooling loop system. To maintain constant temperature of oil supplied for lubrication, a control valve with control from the electronic temperature regulator (controller) is mounted at cooling water discharge from the oil coolers.

Each oil cooler can be shut off from cooling water and oil supply lines for the purpose of cleaning and repair.

For fire safety the fire-resistant oil is used in the system.

Lube oil is purified by means of the following equipment:

Two fine filters with continuous pumping through the filter (the second filter may be out of operation for cleaning) of a part of flow from the operating oil pump; or with pumping through by a special filtration pump (if the oil system is off) or when filling the lube oil tank;

Two gauze rows mounted inside the lube oil tank;

To diminish oil sludging in the pipes, oil supply and discharge headers are designed as filled with oil (not emptied when the lube oil system is stopped). Discharge header remains full at oil system shutdown due to hydraulic gate. Emptying the supply header is prevented by non-return valves (by two in series) installed at pressure side of each lube oil pump.

For pump change-over (till the started pump reaches its full speed) and to prevent unfavourable consequences of the turbine running-down in case of total lube oil supply loss, each turbine set bearing is provided with an emergency reservoir with oil.

The element MAV50ВВ001 in the lube oil system diagram is a hydraulic gate in the header of oil discharge from the bearings which prevents emptying the header and the delivery piping at shutdown (to exclude corrosion of the pipelines).

To separate air dissolved in oil, an air separator is mounted in the tank.

All equipment and piping, in which air may accumulate, have air release devices.

Page 1 of 7

Page 4: MAV Lube Oil System

The lines connecting the oil inlet header with the outlet header are just the small-diameter lines (NB 32), to which the transducers of the system of the lube oil standby pump automatic start-up and the transducers of turbine protection associated with lube oil pressure drop are connected. Closing the valve at oil inlet into this line and opening the outlet valve it is possible to decrease pressure to the transducers and to test the respective system by real pressure drop to make sure it is functioning properly.

Oil vapours are removed from the bearing casings and the oil tank by a exhauster.

Different to the other fire-resistant liquids used by other turbine manufacturers OMTI does not need regeneration during operation.

3. LIST OF EQUIPMENT

Oil tank MAV10BB001;

Oil pumps with AC motor MAV11AP001, MAV12AP001;

Oil pump with DC motor MAV13AP001 (emergency);

Oil pump for oil circulation and filtration MAV18AP001;

Exhauster MAQ10AN001;

Oil coolers MAV21AC001, MAV22AC001, MAV23AC001, MAV24AC001;

Fine filters MAV16AT001, MAV17AT001;

4. NORMAL OPERATIN OF THE SYSTEM

Lubrication oil system should be in operation from the beginning of the unit start-up to cooling-down of the turbine cylinders to 150C after the turbine trip (until the barring gear switch-off).

During operation of the lubrication system one AC lubrication pump is switched on and delivers oil to the bearings. The other pumps are in reserve, they are ready to start. Oil vapour evacuation exhauster is also in operation. Operation without oil vapour exhauster is permitted for a limited time period required for its repair. In this case oil vapours are evacuated at the expense of natural draft in the vertical exhaust pipe. During start-up and shut-down of the Unit oil is supplied to the suction of rotor jacking oil pumps. In case of temperature rise of oil to the bearings up to 40C, a cooling water is supplied through the oil coolers. Oil temperature will be maintained automatically at this level by means of a control valve at cooling water discharge.

At oil temperature in the tank of 60оС, as soon as water is lighter than OMTI, water will evaporate from the oil surface. In this connection short-duration water leakage in amount of 0.5 m3/h are permissible. However, for continuous operation it is not acceptable because ageing of oil will speed up. For continuous operation the leakage should not exceed 0.1 m3/h.

5. SYSTEM OPERATION UNDER ABNORMAL OPERATING CONDITIONS

Pressure Drop in Lubrication System

If oil pressure in the lubrication system drops down to the specified limit, a stand-by and an emergency lube oil pump come into operation automatically. If the reserve pump operates normally, the emergency pump is switched off by the operating personnel.

Oil Temperature Rise

In case of oil temperature rise above the specified limit, the temperature regulator is automatically disconnected from the control valve at cooling water line and the latter gets fully open.

Page 2 of 7

Page 5: MAV Lube Oil System

Oil Level Drop in the Oil Tank

If the level of the oil in the tank drops, the system should be checked for leaks, and after attending the leaks when there is no oil leakage from the system, lubrication oil should be added into the tank during unit operation so that normal level is maintained.

Clogging of Filter

In case of differential pressure rise in the fine filters or at the gauzes inside the oil tank, the respective filter should be cleaned.

Failure at Oil Pump Start-up

If the operating pump is switched off and the reserve pump fails to start, the Unit is shut down. Loss in power supply to the reserve pumps with the running emergency pump should not exceed the specified time (20 s) – in order to maintain capacity of the battery for turbine generator normal running-down. If the emergency pump also failed to start, automatic protection will trip the turbine with a time delay of 3s.

Break of Lube Oil Piping

Owing to usage of fire-resistant oil of OMTI type in the lubrication system, break of lube oil discharge piping does not result in intensive ignition and fire.

Due to individual emergency reservoirs located in bearing covers, oil wedge pressure in bearings will not fall during turbine rotor running-down.

Failure of Lubrication System Exhauster Start-up

Operation without the exhauster is permitted during the limited time period required for repair.

6. BACK UP SYSTEM REQUIREMENT

In case of failure of lube oil supply to bearings, emergency reservoirs located on the bearings supply oil to bearings.

Page 3 of 7

Page 6: MAV Lube Oil System

TECHNICAL DATA

KKS codeName of

equipmentType, technical

dataQnty Material

Mass of one piece,

kg

MAV10BB001 Lube oil tank V=70 m3 1 Two-ply corrosion-resistant steel

16000

MAV11AP001MAV12AP001

Oil pump with AC electric motor

AMKB-500-35Q=500 m3/hH=34 m w.c.

2 Carbon steel, stainless steel, alloyed steel

1460

MAV13AP001 Oil pump with DC electric motor

AMKB-500-35бQ=430 m3/hH=20 m w.c.

1 Carbon steel, stainless steel, alloyed steel

1360

MAV18AP001 Oil filtration and circulation pump

Ш-40-4.1-19.5Q=19.5 m3/hH=40 m w.c.

1 Carbon steel, alloyed steel

220

MAQ10AN001 Exhauster B-Ц14-46-4Q=7000 m3/h

H=150 mm w.c.

1 Carbon steel, alloyed steel

90

MAV21AC001MAV22AC001MAV23AC001MAV24AC001

Oil cooler MП330-300-1F=440 m2

Qw=300 m3/hQoil=330 m3/h

4 Carbon steel (shell), stainless steel (tubes)

4500

MAV16AT001MAV17AT001

Fine filter F=3.5 m2

Qw=20 m3/h2 Carbon steel 350

7. POWER SUPPLIES

Electrically (AC) driven components of MAV system receive power from the normal operation power supply system under all design operating conditions.

In case of loss of normal operation power supply the lube oil pump AC motors (MAV11P001 and MAV12P001) get connected to the normal operation reliable (from the diesel-generator of the turbine hall) power supply system.

The electric motor of the emergency lubrication pump (MAV13P001) is powered from the battery.

8. INSTRUMENTATION

Control over motor-driven equipment and valves, supervision over position (status) of elements, monitoring process parameters, alarm and warning signalling as well as recording the parameters and events in the full scope for all operating modes are envisaged to be executed at Main Control Room.

Page 4 of 7

Page 7: MAV Lube Oil System

9. PROTECTIONS AND INTERLOCKS

EquipmentInterlock No.

Description of interlocks and protections

Lubrication pump MAV11AP001

MAV 1.1 Electric motor of the pump is powered from normal power supply with change-over to the diesel-generator in case of loss of normal power supply.

MAV 1.2 The pump is started automatically:

in case of pump MAV12AP001 trips either spontaneous or under action of motor protection, or in result of power supply loss.

if pressure of oil for lubrication MAV30CP002 falls to limit 1 and with this either pump MAV12AP001 is in operation and the preset time has passed from the moment of its switching on (no more than 60 s), or any of the conditions listed in MAV 1.3. is available.

MAV 1.3 BG motor is switched on;

or there is no signal about closure of more than one HP stop valve;

or the temperature of HPC outer surface at steam admission MAA10CT011 exceeds the preset value;

or turbine speed MAX51CS001 is not equal to zero.

MAV 1.4 From CCR it is possible to switch on the pump at any time and to switch it off if pump MAV12AP001 is in operation or if none of conditions of MAV 1.3. is available (i.e. at stand-still cold turbine).

MAV 1.5 At short loss of AC power supply (no more than 3 s) automatic restarting (self start-up) of operating lubrication pump should take place.

Lubrication pump MAV12AP001

MAV 2.1 Power supply and control conditions are absolutely similar to those of pump MAV11AP001. To realize an interlock associated with pressure drop in lubrication system down to limit 1, a signal from pressure relay MAV30CP003 is used.

Lubrication pump MVB13AP001

MAV 3.1 Electric motor of the pump is powered from battery.

MAV 3.2 The pump is started automatically if lube oil pressure falls to limit II MAV30CP004 and with this one of AC pumps (MAV11AP001 or MAV12AP001) is in operation or any of the conditions of MAV 1.3. is available.

MAV 3.3 From CCR it is possible to switch on the pump at any time or to switch it off if none of above mentioned conditions (MAV 1.3) is available. If any of conditions of MAV 1.3. is available, the pump is allowed to be switched off manually provided that any one of AC pumps is in operation.

MAV 3.4 If more than 20 sec have been passed from the moment of the pump switching on and any HP stop valve is not closed, the alarm at the CCR appears

Exhauster of lubrication systemMAVQ10AN001

MAV 4.1 Electric motor of the exhauster is powered from power lines of normal power supplies

MAV 4.2 Exhauster is switched on when switching on any of lubrication pumps and is switched off with a lag time of 15 min after all lubrication pumps have switched off (it is possible to take into account only AC oil pumps). Automatic commands for switching on/off are of pulse type, they do not prevent switching the pump on/off manually.

MAV 4.3 If interlock of MAV 4.2.is enabled, operator's control over the exhauster from CCR is not provided. If control from CCR is provided, it should be possible to switch off/on the exhauster at any time.

Pump to fill and empty the oil tankMAV18AP001

MAV 5.1 Electric motor of the exhauster is fed from normal power supplies

MAV 5.2 At turbine operation the pump is used for periodical pumping of oil through the filter. Does not have control from CCR.

Page 5 of 7

Page 8: MAV Lube Oil System

10. ALARMS AND ACTIONS

Parameter name Marking

Value and measur. unit

INFORMATION

Oper. Max Indicat. Signalling.Min. Place

(SCR, MCR, etc)

Mode (ind.,

ICS, call)

Mode (ind., light

annum. or ICS)

Preset value & directio

n

DР at oil tank gauze

MAV10CP001 200 mm 400 mm CCR ICS ICS 400 mm raise0 mm

Р of oil at lube oil pump discharge

MAV11CP501MAV12CP501MAV13CP501

0.4 MPa 0.44 MPa Local - -0 MPa

Р of oil ahead of oil cooler

MAV20CP501 0.4 MPa 0.44 MPa Local - - -0 MPa

Р of oil for lubrication

MAV30CP001 0.12 MPa

0.13 MPa CCR ICS - -0 MPa

P of oil for lubrication

MAV30CP051 0.12 MPa

0.13 MPa - - Ind. light (com.)

0.07 MPa fall0 MPa

P of oil for lubrication

MAV30CP002 MAV30CP003 MAV30CP004

0.12 MPa

0.13 MPa - - Emerg. 0.03 MPa fall0 MPa

Р of oil for lubrication

MAV30CP502 0.12 MPa

0.13 MPa Local - -0 MPa

Р of oil in lines to pressure relays

MAV30CP503 MAV30CP504 MAV30CP504

0.12 MPa

0.13 MPa Local - -0 MPa

Р of oil ahead of reduction valve

MAV30CP501 0.4 MPa 0.44 MPa Local - -0 MPa

Р of oil ahead of fine filter

MAV17CP501 MAV18CP501

0.4 MPa 0.44 MPa Local - -0 MPa

P of cooling water PGB10CP501 0.5 MPa 0.55 MPa Local - -0 MPa

H of cooling water control valve

PGB20CG201 70% 100% CCR Call - -0%

Т of oil ahead of oil coolers

MAV20CT001 60С 75С CCR ICS - -15С

Т of oil after oil coolere

MAV21CT001 MAV22CT001 MAV23CT001 MAV24CT001

40С 55С CCR ICS ICS 45С raise15С

Т of oil for lubrication

MAV30CT001 40С 50С CCR ICS ICS 45С raise20С

T of cooling water ahead of oil coolers

PGB10CT001 35С 39С CCR ICS - -20С

T of cooling water after of oil coolers

PGB11CT001 PGB12CT001 PGB13CT001 PGB14CT001

39С 45С CCR ICS - -

20С

L of oil in oil tank MAV10CL001 300 mm 1000 mm CCR ICS ICS 900 mm raise 100 mm fall

0 mm

L of oil in oil tank MAV10CL501 200 mm 1000 mm Local - - -0 mm

11. TROUBLE SHOOTING :

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Page 9: MAV Lube Oil System

12. HAZARDS AND PRECAUTIONS :

13. MAINTENANCE :

14. REFERENCE : DPR\3_1.10

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