o&m manual 500 mw turbogenerator

7/24/2019 O&M Manual 500 MW TurboGenerator

1/447

HARIDWAR

BHARAT HEAVY ELECTRICALS LIMITED

Heavy Electrical Equipment Plant

OPERATION & MAINTENANCE

MANUAL

FOR

500 MW TURBOGENERATOR

WITH

WATER COOLED STATOR WINDING &

DIRECT HYDROGEN COOLED ROTOR WINDING

Project :NCTPP Stage -2 DADRI-2 x490MW

Customer :NTPC

BHEL Order no : 10550A12901 DADRI UNIT 1

10554A12901 DADRI UNIT 2


2/447

BHEL,Haridwar

Turbogenerators

General

Table of Contents

2.0-0010-10550/1

0209E

Cover Sheet 0.0-0000

GENERAL

Table of Contents . . . . . . . . . . . . . . . . . . 2.0-0010

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0-0030

Notes on the Use of the Manual . . . . . . . . . 2.0-0040

Operation Beyond Contract Commitment . . 2.0-0050

Safe Disposal of Turbogenerator Items 2.0-0200

DESCRIPTION

Brief Description

Rating Plate Data . . . . . . . . . . . . . . . . . . . 2.1-1002Generator Cross Section . . . . . . . . . . . . 2.1-1050

Generator Outline Diagram . . . . . . . . . . 2.1-1056

Exciter Outline Diagram . . . . . . . . . . . . . 2.1-1058

Design and Cooling System . . . . . . . . . 2.1-1100

Generator Cooling Gas Circuit . . . . . . . 2.1-1150

Stator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-1210

Stator Winding . . . . . . . . . . . . . . . . . . . . . 2.1-1230

Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-1300

Hydrogen Cooler . . . . . . . . . . . . . . . . . . . 2.1-1440

Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-1450

Shaft Seals . . . . . . . . . . . . . . . . . . . . . . . . 2.1-1460

Oil Supply for Bearings and Shaft Seals . . 2.1-1510

Seal Oil System (Simplified Diagram) 2.1-1511

Gas System . . . . . . . . . . . . . . . . . . . . . . . 2.1-1520

Gas System (Simplified Diagram) . . . . 2.1-1521

Primary Water System . . . . . . . . . . . . . . 2.1-1530

Primary Water System (Simplified Diagram) . 2.1-1531

Technical Data

General and Electrical Data . . . . . . . . . 2.1-1810

Mechanical Data . . . . . . . . . . . . . . . . . . 2.1-1820

Seal Oil System . . . . . . . . . . . . . . . . . . . 2.1-1825

Gas System . . . . . . . . . . . . . . . . . . . . . . . 2.1-1826

Primary Water System . . . . . . . . . . . . . . 2.1-1827Waste Gas System . . . . . . . . . . . . . . . . 2.1-1828

Excitation System . . . . . . . . . . . . . . . . . . 2.1-1829

Cooler Data . . . . . . . . . . . . . . . . . . . . . . . 2.1-1830

Reactive Capability Curve . . . . . . . . . . . 2.1-1850

Load Characteristic of pilot exciter . . . 2.1-1860

Gas Specification . . . . . . . . . . . . . . . . . . 2.1-1883

Primary Water Specification . . . . . . . . . 2.1-1885

Specification for Ion Exchange Resins 2.1-1887

Additive Specification for Alkalizer Unit 2.1-1888

Stator

Stator Frame . . . . . . . . . . . . . . . . . . . . . . 2.1-2100

Stator End Shields . . . . . . . . . . . . . . . . . 2.1-2150

Generator Terminal Box . . . . . . . . . . . . 2.1-2170

Hydraulic Testing and Anchoring of Stator 2.1-2190Anchoring of Generator on Foundation 2.1-2191

Stator Core . . . . . . . . . . . . . . . . . . . . . . . . 2.1-2200

Mounting of Stator Core in Stator Frame 2.1-2201

Spring Support of Stator Core . . . . . . . . 2.1-2220

Stator Winding . . . . . . . . . . . . . . . . . . . . . 2.1-2300

Connection Diagram of Stator Winding 2.1-2301

Stator Slot . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-2303

Transposition of Stator Bars . . . . . . . . . 2.1-2305

Micalastic High Voltage Insulation . . . . 2.1-2320

Construction of High Voltage Insulation 2.1-2321

Corona Protection . . . . . . . . . . . . . . . . . . 2.1-2330

Coil and End Winding Support System 2.1-2340Stator End Winding. . . . . . . . . . . . . . . . . 2.1-2341

Electrical Connection of Bars, Water Supply

and Phase Connectors . . . 2.1-2350

Electrical Bar Connections and Water Supply 2.1-2351

Terminal Bushings. . . . . . . . . . . . . . . . . 2.1-2370

PW Connection for Terminal Bushings and

Phase Connectors . . . . . . . . . . 2.1-2371

Cooling of Terminal Bushings . . . . . . . 2.1-2372

Components for Water Cooling of Stator

Winding . . . . . . . . . . . . . . . . . . 2.1-2380

Grounding of Stator Cooling Water Manifold . . 2.1-2389

Rotor

Rotor Shaft . . . . . . . . . . . . . . . . . . . . . . . . 2.1-3000

Cooing of Rotor Winding . . . . . . . . . . . . 2.1-3100

Cooling Scheme of Rotor Winding . . . . 2.1-3101

Rotor Winding. . . . . . . . . . . . . . . . . . . . . . 2.1-3300

Rotor Slot . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-3301

Rotor End Winding . . . . . . . . . . . . . . . . . 2.1-3310

Rotor Retaining Ring . . . . . . . . . . . . . . . 2.1-3350

Rotor Field Connections . . . . . . . . . . . . 2.1-3370

Electrical and Mechanical Connection of EE

Coupling . . . . . . . . . . . . . . . . . 2.1-3373

Rotor Fan . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-3600

Cooler

Hydrogen Cooler (Description) . . . . . . . 2.1-4000

Hydrogen Cooler (Drawing) . . . . . . . . . 2.1-4001

Generator Bearings

Generator Bearing (Description) . . . . . 2.1-5000

Generator Bearing (Drawing) . . . . . . . . 2.1-5001

Measurement of Bearing Temperature 2.1-5003

Generator Bearing Insulation . . . . . . . . 2.1-5005


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2.0-0010-10550/2

0209E

Shaft Seal

Shaft Seal . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-6000

Shaft Seal (Drawing) . . . . . . . . . . . . . . . 2.1-6001

Seal Oil System

Seal Oil System . . . . . . . . . . . . . . . . . . . 2.1-7100

Differential pressure Valve A . . . . . . . . . 2.1-7101

Differential Pressure Valve C . . . . . . . . 2.1-7103

Pressure Equalizing Control Valve. . . 2.1-7104

Seal Oil System Schematic Diagram . 2.1-7111

List of Valves for Seal Oil System. . . . 2.1-7112

Bearing Vapour Exhauster. . . . . . . . . . . 2.1-7120

Seal Oil Pumps. . . . . . . . . . . . . . . . . . . . 2.1-7123

Seal Oil Cooler and Seal Oil Filter. . . . 2.1-7130

Seal oil Cooler (Drawing) . . . . . . . . . . . 2.1-7131

Seal Oil Filter (Drawing) . . . . . . . . . . . . 2.1-7132

Differential Pressure Meter Syste. . . . 2.1-7150

Gas System

Gas System. . . . . . . . . . . . . . . . . . . . . . . 2.1-7200

Gas System Schematic Diagram. . . . 2.1-7211

List of Valve for Gas System. . . . . . . . . 2.1-7212

CO2 Vaporiser. . . . . . . . . . . . . . . . . . . . 2.1-7230

Gas Dryer (Refrigeration type) . . . . . . 2.1-7270

Primary Water System

Primary Water System. . . . . . . . . . . . . . 2.1-7300

Primary Water System Schematic Diagram. . 2.1-7311List of Valves for Primary Water System 2.1-7312

Primary Water Pumps. . . . . . . . . . . . . . 2.1-7320

Primary Water Cooler. . . . . . . . . . . . . . . 2.1-7330

Primary Water Treatment System. . . . 2.1-7340

Alkalizer Unit for Primary Water Circuit 2.1-7341

Primary Water Filters. . . . . . . . . . . . . . . 2.1-7343

Primary Water Main Filter. . . . . . . . . . . . 2.1-7344

Primary Water Fine Filter. . . . . . . . . . . . 2.1-7345

Protective Screens at Primary Water Inlet

and Outlet. . . . . . . . . . . . . . . . . 2.1-7349

Automatic Controls

Coolant Temperature Control. . . . . . . . 2.1-8010

Protective Devices

Safety Equipment for Hydrogen Operation. . 2.1-8310

Waste Gas System. . . . . . . . . . . . . . . . . 2.1-8311

List of Valves for Waste Gas System . 2.1-8312

Generator Waste Fluid System . . . . . . 2.1-8315

Generator Mechanical Equipment Protection. 2.1-8320

Tripping Scheme for Generator Mechanical

Equipment Protection 2.1-8321

Generator Mechanical Equipment Protection . 2.1-8323

Generator Electrical Protection. . . . . . . 2.1-8330

Tripping Scheme for Generator Electrical

Protection . . . . . . . . . . . . . 2.1-8331

Rotor Grounding System . . . . . . . . . . . 2.1-8350

Arrangement of Brush Holders for Rotor

Grounding System. . . . . . . . . 2.1-8351

Measuring Devices and SupervisoryEquipment

Introduction. . . . . . . . . . . . . . . . . . . . . . . . 2.1-8400

Temperature Transducers. . . . . . . . . . . 2.1-8410

Supervision of Generator. . . . . . . . . . . . 2.1-8420

Generator measuring points. . . . . . . . . 2.1-8422

List of Valves for Generator System. . . . . 2.1-8423

Supervision of Bearings. . . . . . . . . . . . . 2.1-8440

Supervision of Seal Oil System. . . . . . 2.1-8450

Supervision of Gas System. . . . . . . . . 2.1-8460

Supervision of Primary Water System 2.1-8470

Supervision of Exciter. . . . . . . . . . . . . . 2.1-8490Exciter Measuring Points. . . . . . . . . . . 2.1-8491

Excitation System

Exciter . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-9100

Basic Arrangement of Brushless Excitation

System. . . . . . . . . . . . . . . 2.1-9101

Rectifier Wheels. . . . . . . . . . . . . . . . . . . 2.1-9102

Rectifier Wheels and Coupling. . . . . . 2.1-9103

Permanent-Magnet Pilot Exciter Rotor & Fan 2.1-9104

Exciter Cross Section. . . . . . . . . . . . . . 2.1-9110

Exciter Cooling Air Circuit. . . . . . . . . . . 2.1-9120

Stroboscope for Fuse Monitoring . . . . 2.1-9140Exciter Drying . . . . . . . . . . . . . . . . . . . . . 2.1-9150

Ground Fault Detection System for Exciter

Field Circuit. . . . . . . . . . . . . 2.1-9180

Arrangement of Bursh Holders for Ground

Fault Detection System . . 2.1-9181

Brush Holders for Ground Fault Detection

System. . . . . . . . . . . . . . 2.1-9182

Operation

Operating and Setting Values-General 2.3-4000

Gas Quantities. . . . . . . . . . . . . . . . . . . . 2.3-4010Measuring Point List of Generator . . . 2.3-4030

Running Routine-General. . . . . . . . . . 2.3-4100

Operating Log-Generator Supervision 2.3-4120

Operating Log-Seal Oil System . . . . . 2.3-4150

Operating Log-Gas System . . . . . . . . 2.3-4160

Operating Log-Primary Water System 2.3-4170

Operating Log-Exciter Supervision . . 2.3-4190

Start-up

Preparations for Starting-Introduction 2.3-5000

Hints for Cooler Operation. . . . . . . . . . 2.3-5003

Filling and Initial Operation of Air Side Seal


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BHEL,Haridwar

Turbogenerators

General

2.0-0010-10550/3

0209E

Oil Circuit. . . . . . . . . . . . . . . . . 2.3-5110

Filling and Initial Operation of Hydrogen

Side Seal Oil Circuit . . . 2.3-5120

Venting of Seal Oil Circuits. . . . . . . . . . 2.3-5130

Setting of Seal Oil Pressures. . . . . . . 2.3-5150

Setting of Operating Values for Seal Oil System2.3-5160

Measurement of Seal Oil Volume Flows 2.3-5163Functional Testing of Pumps and Exhausters 2.3-5180

Startup of Air Side Seal Oil Circuit . . . 2.3-5210

Startup of Hydrogen Side Seal Oil Circuit. . . . 2.3-5220

Venting of Seal Oil Circuits and Checking of

Seal Oil Pressures . . 2.3-5230

Checking Automatic Operation of Seal Oil

Pumps. . . . . . . . . . . . . . . . 2.3-5280

Positions of Multi-Way Valves in Gas System 2.3-6107

Scavenging the Electrical Gas Purity Meter

System . . . . . . . . . . . . . 2.3-6110

Setting Electrical Zero of Electrical Gas Purity

Meter System . . . . . . . . 2.3-6120

Purity Measurement During CO2 Filling 2.3-6130

Purity Measurement During H2 Filling 2.3-6140

Purity Measurement During H2 Operation 2.3-6150

Gas Filling-Replacing Air With CO2. . . . . . 2.3-6310

Gas Filling-Replacing CO2 With H2. . . . . . 2.3-6320

N2 Purging After Filling of Primary Water

System . . . . . . . . . . . . . . . . . . 2.3-6810

Filling and Initial Operation of Primary Water

System-

Preparatory Work . . . . . . . . . . . . . . . . . . 2.3-7100

Filling External Part of Primary Water Circuit 2.3-7110Filling the Water Treatment System . . 2.3-7120

Filling the Terminal Bushings and Phase

Connectors . . . . . . . . . . . . . 2.3-7150

Filling the Stator Winding . . . . . . . . . . . 2.3-7160

Filling Primary Water Coolers on Cooling

Water Side . . . . . . . . . . . . . 2.3-7180

Activating Primary Water System After a

Shutdown of Less Than 48 Hours 2.3-7210

Activating Primary Water System After a

Shutdown of More Than 48 Hours 2.3-7220

Activating the Primary Water Conductivity

Meter System . . . . . . 2.3-7530Activating the Primary Water Volume Flow

Meter System . . . . . . . . . . . . . 2.3-7540

Initial Operation of Primary Water System -

Checks Prior to Startup . . 2.3-7610

Turning Gear Operation and Runup of

Generator . . . . . . . . . . . . . . . . . . . . . 2.3-8010

Generator Startup Diagram . . . . . . . . . 2.3-8011

Permissible Synchronizing Criteria . . 2.3-8081

On-Load Running

Permissible Load Limits of Generator 2.3-8170

Permissible Loading at Rated PF During

Voltage and Frequency Deviations . . 2.3-8181

Generator Capability With Hydrogen Coolers

out of Service on Water Side 2.3-8184

Unbalanced Load-Time Curve . . . . . . 2.3-8187

Current Overload Capability . . . . . . . . . 2.3-8188

Runback for loss of stator coolant . . 2.3-8190

Unloading schedule for increased cooling water inlet temperature . . 2.3-8191

Shutdown

Shutdown of Generator . . . . . . . . . . . . . 2.3-8310

Generator Shutdown Diagram . . . . . . 2.3-8311

Supervision of Generator during Standstil l

General . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-8400

Coolers . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-8440

Seal Oil System . . . . . . . . . . . . . . . . . . . 2.3-8500

Shutdown of Seal Oil System . . . . . . . 2.3-8510

Draining the air Side Seal Oil Circuit 2.3-8520

Draining the Hydrogen Side Seal Oil Circuit 2.3-8521

Draining the Seal Oil Signal Lines and Seal

Ring Relief Piping . . . . . 2.3-8522

Gas System . . . . . . . . . . . . . . . . . . . . . . 2.3-8600

Gas Removal-Lowering Hydrogen Gas

Pressure in Generator . . . . . . . 2.3-8610

Gas Removal-Replacing H2 with CO2 2.3-8620

Gas Removal-Replacing CO2 With Air 2.3-8630

N2 Purging Before Draining of Primary

Water System . . . . . . . . . . 2.3-8650

Primary Water System . . . . . . . . . . . . . 2.3-8700Shutdown of Primary Water System for Less

Than 48 Hours . . . . . . . . 2.3-8720

Shutdown of Primary Water System for More

Than 48 Hours . . . . . . . . 2.3-8730

Draining the Primary Water System- PW

Coolers (Cooling Water Side) . . . . 2.3-8732

Draining the Primary Water System- Stator

Winding . . . . . . . . . . . . . . . . . 2.3-8734

Draining the PW System-Terminal Bushings

and Phase Connectors 2.3-8738

Draining the Primary Water System- Water

Treatment System . . . . . . . . 2.3-8746Draining the Primary Water System- External

Part of Primary Water Circuit 2.3-8748

Exciter . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-8900

Fault Tracing

General . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-9000

Stator and Generator Supervisory Equipment 2.3-9200

Coolant Temperature Control. . . . . . . 2.3-9280

Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-9310

Coolers . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-9440

Bearings . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-9450

Bearing Vapour Exhausters . . . . . . . . . 2.3-9521


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2.0-0010-10550/4

0209E

Seal Oil Pumps . . . . . . . . . . . . . . . . . . . 2.3-9523

Seal Oil Pressures and Temperatures 2.3-9531

Relief Valves in Seal Oil System 2.3-9551

Oil Level in Seal Oil System . . . . . . . . 2.3-9561

Gas Pressures . . . . . . . . . . . . . . . . . . . 2.3-9640

Gas Purity Meter System . . . . . . . . . . . 2.3-9680

Primary Water Pumps . . . . . . . . . . . . . . 2.3-9720Water Pressures and Temperatures in

Primary Water System . . . . . . . . 2.3-9730

Filters in Primary Water System . . . . . 2.3-9740

Water Level in Primary Water Tank . . . 2.3-9760

Conductivity in Primary Water System 2.3-9782

Volume Flow Rates in Primary Water System 2.3-9784

Alkalizer Unit for Primary Water System 2.3-9785

Fuses on Rectifier Wheels . . . . . . . . . 2.3-9901

Exciter Temperatures . . . . . . . . . . . . . . 2.3-9911

Exciter Cooler . . . . . . . . . . . . . . . . . . . . . 2.3-9914

Stroboscope . . . . . . . . . . . . . . . . . . . . . . 2.3-9941

Exciter Drying System . . . . . . . . . . . . . 2.3-9955

Ground Fault Detection System in Exciter

Field Circuit . . . . . . . . . . . . . 2.3-9980

Maintenance and supervision-

Introduction. . . . . . . . . . . . . . . . . . . . 2.4-4200

Stator. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4-4210Generator Coolers . . . . . . . . . . . . . . . . . 2.4-4240

Bearings . . . . . . . . . . . . . . . . . . . . . . . . . 2.4-4250Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4-4310Seal Oil Pumps & Bearing Vapour Exhauster 2.4-4520Seal Oil Coolers . . . . . . . . . . . . . . . . . . . 2.4-4540

Seal Oil Filters . . . . . . . . . . . . . . . . . . . . 2.4-4550Gas Consumption . . . . . . . . . . . . . . . . . 2.4-4610Primary Water Pumps . . . . . . . . . . . . . . 2.4-4720Primary Water Filters . . . . . . . . . . . . . . . 2.4-4740Primary Water Coolers. . . . . . . . . . . . . 2.4-4750Water Level in Primary Water Tank . . . 2.4-4760Concutivity Meter System. . . . . . . . . . . . 2.4-4780Alkalizer Unit . . . . . . . . . . . . . . . . . . . . . . 2.4-4785Fuses on Rectifier Wheels. . . . . . . . . . 2.4-4910Exciter Dryer . . . . . . . . . . . . . . . . . . . . . . 2.4-4925Ventilation and Make-Up Air Filters 2.4-4930Exciter Coolers . . . . . . . . . . . . . . . . . . . . 2.4-4940Ground Fault Detection System. . . . . . 2.4-4990

Inspection

Introduction. . . . . . . . . . . . . . . . . . . . . . . . 2.5-0010Determination of Dewpoint Temperature 2.5-0019Packing,Transport, Storage of Gen Rotors 2.5-0030Preventive Measures for Transport and

Storage of Generator Rotors . 2.5-0031Checking Desiccant in Gen Rotor Packing 2.5-0032Insulation Resistance Measurements on

Rotor and Exciter Windings. . . . 2.5-0033Preparation of Machinery Parts . . . . . . 2.5-0200

Checking the Bearing and Seal Insulation . . 2.5-0300Test Norms During Overhaul . . . . . . . . 2.5-0305

Leakage Tests of Generator and Gas System 2.5-0310Flushing the Oil Piping . . . . . . . . . . . . . 2.5-0320Measures to Prevent Corrosion During

Inspecitons . . . . . . . . . . . . . 2.5-1003Preventive Measures to Avoid Stress

Corrosion . . . . . . . . . . . . . . . 2.5-1005

Inspection Schedule-Foreword . . . . . . 2.5-1010Inspection Schedule-Stator . . . . . . . . . 2.5-1020Inspection Schedule-Rotor . . . . . . . . . 2.5-1030Inspection Schedule-Coolers . . . . . . . 2.5-1040Inspection Schedule-Bearings . . . . . . 2.5-1050Inspection Schedule-Shaft Seals . . . . 2.5-1060Inspection Schedule-Seal Oil System 2.5-1071Inspection Schedule-Gas System . . . 2.5-1072Inspection Schedule-Primary Water System 2.5-1073Inspection Schedule-Generator Supervisory

Equipment. . . . . . . . . . 2.5-1080Inspection Schedule-Excitation System 2.5-1090Measures for Preservation of Generator

During Standstill. . . . . . . . . . . . . . . . . 2.5-1100Stator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5-2000Cementing the Joints of Profiled Gaskets. . 2.5-2120

Sealing Generator End Shield Joints . 2.5-2160IR Measurements on Stator Winding 2.5-2300Procedure for carrying out Tan delta test with

End Winding Vibration probes in position 2.5-2305Drying the Windings . . . . . . . . . . . . . . . 2.5-2310Test Instruction for Stator Slot Support System

With Top Ripple Springs . . 2.5-2340Stator Slot Support System-Radial Wedge

Movements-Test Record . . 2.5-2341

Test Equipment for Stator Slot Support System 2.5-2342Instructions for Checking the Stator Slot Support System. . . . . . . . . . . . . 2.5-2343

Rewedging of Stator Winding. . . . . . . . 2.5-2345Cementing Stator Slot End Wedges at Turbine

and Exciter Ends. . . . . . 2.5-2346Treatment of Bolted Contact Surfaces 2.5-2350Rotor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5-3000Insulation Resistance Measurements on Rotor

and Exciter Windings 2.5-3300Ultrasonic Examination of Rotor Retaining

Rings at Power Plant . . . 2.5-3357Hydrogen Coolers. . . . . . . . . . . . . . . . . . 2.5-4000

Insertion and Removal of Hydrogen Coolers 2.5-4100Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . 2.5-5000Shaft Seals. . . . . . . . . . . . . . . . . . . . . . . . 2.5-6000Seal Oil System. . . . . . . . . . . . . . . . . . . . 2.5-7100Seal Oil Pumps & Bearing Vapour Exhausters 2.5-7120Seal Oil Coolers. . . . . . . . . . . . . . . . . . . 2.5-7130Gas System. . . . . . . . . . . . . . . . . . . . . . . 2.5-7200Primary Water System. . . . . . . . . . . . . . 2.5-7300Primary Water Pump. . . . . . . . . . . . . . . . 2.5-7320Primary Water Coolers . . . . . . . . . . . . . 2.5-7330Treatment and Cleaning of Pipes in Primary

Water Circuit . . . . . . . . . 2.5-7381Flushing External Part of Primary Water Circuit2.5-7382

Leakage Test of External Primary Water Circuit2.5-7384Excitation System-Exciter . . . . . . . . . . . 2.5-9000Checking the Insulation Resistance of Heat

Sink Insulation . . . . . . . . . . 2.5-9010Checking the Insulation at Rectifier Wheels 2.5-9011


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Turbogenerators

General

Preface

2.0-0030-10550/1

0209E

This manual conta ins in format ion on

operation and maintenance of Turbogeneratorand its auxillary systems.

The information has been prepared on the

assumpt ion tha t the opera t ing and

maintenance personnel have a basic

knowledge of power plant engineering and

operation. It is an essential prerequisite for

satisfactory operation and maintenance of the

turbogenerator that the operat ing and

maintenance personnel are fully familiar with

the design of the turbogenerator plant andhave aquired thorough training in operation

and maintaining the unit.

The manual is subdevided into following

main sections

-General

-Description

-Operation

-Maintenance

-Inspection


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General

Notes on the Use of the Mannual

The turbogenerator instruction manual consists

of the following manual sections:

2.0 General

2. 1 Desc ri pti on

2.3 Operation

2.4 Maintenanceand Supervision

2.5 Inspection

Each sect ion contains a number of separate

instructions.

The manual contains a Table of Contents together

with a List of Effect ive Pages . Please check your

manual against this list and advise if there are any

omissions.

Identif icat ion Number

The identification number consists of the above

mentioned section number, supplemented by a four-

digit code number. It is indicated in the bottom most

line of the pages.

For the user of the manual, the identification

number is a suf f ic ient reference for locat ing aparticular instruction number must be indicated.

Instruct ion Number

The instruction number consists of the manual

section number, the identificati on number, the variant

number, the page number, and the date with the

language symbol.

2.0 - 0040 - 00009 / 1

1205 E

Manual section number

Identification number

Variant number

Page number

Language (English)

Date (mm yy)

2.0-0040-10550/1

0209E


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BHEL,Haridwar

Turbogenerators

General

Operation Beyond Contract

Commitment

The Turbogenerator set has been designed and

manufactured to meet the contract commitment asregards to the capability for the continuous operation

or variable load operation below maximum continuous

rating with an aim to achieve objective of securing

long life and trouble free operation.

Because of the margin provided in the design, it

may be possible to operate the turbogenerator at

overloads for the time specified in the manual.

However, such operations although possible for the

short time will encroach upon the design margin built

into the generator.

The Turbogenerator is designed to operate within

the temperature rise in accordance with EC standard.

Operating the generator in excess of the capability

curves which are part of this O & M Manual will cause

increase in Copper temperature, thermal expansion

and higher insulation stresses. Such operation is notpermitted by the manufacturer.

Continued operation of unit without recommended

scheduled maintenance will eventually result in

increased maintenance and reduction in the useful

life of the machine. BHEL cannot be responsible for

any malfunctioning occurring as a result of operation

beyond the contract limits and operation of machine

without carrying out scheduled maintainance/

inspection. Such operation if undertaken by the user

must be at his own risk.

BHEL reserves the right of changing the operation

and maintainance instructions based on experience

gained.

2.0-0050-10550/1

0209E


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General

In lin e with ISO 14001 requi rements HEEP-BHEL,

Haridwar has adopted an Environmental policy and

has pledged to fulfil its responsibi lity of protecting

and conserving the environment around itself.

The mater ials, which are scrapped dur ing

inspections and capital overhaul after consumption of

their useful life, are disposed in an environment friendly

manner to protect our natural resources and control

environment pollution.

Guidelines given in the following paragraphs can

go a long way in planning the activity of scrapping the

hazardous material effectively in an echo friendlymanner.

A proper system of waste disposal should also be

evolved and its compliance ensured and necessary

precautions as published from time to time adhered to

while disposing hazardous material.

Generator is manufactured mainly from three

types of items namely,

1. Metals :

Structured steel, Cast steel, Forged steel, brass,bronze etc.

2. Non Metals:

Rubber, insulation, plastics, glass etc.

3. Lubri cating oi l and Greases.

Dispos al of Generator wastes:

1. Metals :

May be disposed as scrap metal for recycling and

reuse.

2. Non- Metals:

a) Rubber:

Residue of fluoro-elastomer products, obtained by

exposure of fluoro-elastomers like O-rings, rubbers etc.

at very high temperature above 400 degree C, in extreme

case of fire etc, should be disposed with great care, such

as very high incineration.

b) Insulation:

Insulation material should be disposed by very high

incineration.

c) Plastics and glass:

May be disposed as scrap material for recycling and

reuse.

3. Lubricatin g Oil and Grease:

These items can be disposed/recycled/ reused as

follows:

a) Lubricating Oil :

To be recycled after cleaning as far as possible. After

it has become unserviceable, it may be disposed as

follows:

Send the discarded oil to registered refiners who

have facilities to reclaim the oil by

- physio-chemical treatment for further use in

noncritical applications.

- send the used oil to parties who are licensed to

handle and dispose used lubricating oil.

- burn off the discarded oil in boiler furnace by

mixing with fuel oil.

b) Grease:

I t may be disposed for reuse as low-grade

lubrication.

2.0-0200-10550/1

0209E

Safe Disposal of Turbogenerator Items


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General

Rating Plate Data for Generator

Project name: NCTPP Stage-II DADRI Unit-1 10550A12901

Unit-2 10554A12901

IEC: 34

BHARAT HEAVY ELECTRICALS LTD

KW : 490,000

Gas Pressure : 3.5 Kg/cm2(g)

P.F. 0.85 Lag

R.P.M : 3000

Insulation : Class F

KVA : 577,000 Hz : 50

Type: THDF 115/59

StatorVolts 21000

Amps 16200

Phase 3

Conn. Y Y

Spec. IS: 5422

I I

RotorAmps 3973

Volts 334

DIV : HaridwarMADE IN INDIA

Coolant: Hydrogen & Water

2.1-1002-10550/1

0209E


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General


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General

General Outline Drawing

2.1-1056-10550/1

0209E


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BHEL,Haridwar

Turbogenerators

General

Weights:

Total Weight 39 300 kg

Rotor 7 550 kg

Coolers (without water) 1 860 kg

Exciter Outline Drawing

ELR 70/90-30/6-20ELR 50/42-30/16

2.1-1058-10550/1

0209 E


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Turbogenerators

General

General Design Features

Design and Cooling System

2.1-1100-10550/1

0209E

1. General

The two-pole generator uses direct water coolingfor the stator winding, phase connectors and bushings

and direct hydrogen cooling for the rotor winding. The

losses in the remaining generator components, such as

iron losses, windage losses and stray losses, are also

dissipated through hydrogen.

The generator frame is pressure-resistant and gas

tight and equipped with one stator end shield on each

side. The hydrogen coolers are arranged vertically inside

the turbine end stator end shield.

The generator consists of the following components :

Stator

Stator frame

End shields

Stator core

Stator winding

Hydrogen coolers

Rotor

Rotor shaft

Rotor winding

Rotor retaining rings

Field connections

BearingsShaft seals

The following additional auxiliaries are required for

generator operation :

Oil system

Gas system

Primary water system

Excitation system

2 Cooling System

The heat losses arising in the generator interior aredissipated to the secondary coolant (raw water,

condensate etc.) through hydrogen and primary water.

Direct cooling essentially eliminates hot spots and

differential temperatures between adjacent components

which could result in mechanical stresses, particularly

to the copper conductors, insulation, rotor body and

stator core.

3. Hydrogen Coo ling Ci rcu i t

The hydrogen is circulated in the generator interior

in a closed circuit by one multi-stage axial-flow fanarranged on the rotor at the turbine end. Hot gas is drawn

by the fan from the air gap and delivered to the coolers,

where it is re-cooled and then divided into three flow

paths after each cooler.

Flow path I is directed into the rotor at the turbine

end below the fan hub for cooling of the turbine end half

of the rotor.

Flow path II is directed from the coolers to the

individual frame compartments for cooling of the stator

core.

Flow path III is directed to the stator end winding

space at the excitor end through guide ducts in the frame

for cooling of the exciter end half of the rotor and of the

core end portions.

The three flows mix in the air gap. The gas is then

returned to the coolers via the axial-flow fan.

The cooling water flow through the hydrogen

coolers should be automatically controlled to maintain a

uniform generator temperature level for various loads

and cold water temperatures.

4. Coo li ng of Rot or

For direct cooling of the rotor winding, cold gas is

directed to the rotor end windings at the turbine and

excitor ends. The rotor winding is symmetrical relative

to the generator center line and pole axis. Each coilquarter is divided into two cooling zones. The first cooling

zone consists of the rotor end winding and the second

one of the winding portion between the rotor body end

and the mid-point of the rotor. Cold gas is directed to

each cooling zone through separate openings directly

before the rotor body end. The hydrogen flows through

each individual conductor in closed cooling ducts. The

heat removal capacity is selected such that

approximately identical temperatures are obtained for

all conductors. The gas of the first cooling zone is

discharged from the coils at the pole center into a

collecting compartment within the pole area below theend winding. From there the hot gas passes into the air

gap through pole face slots at the end of the rotor body.

The hot gas of the second cooling zone is discharged

into the air gap at mid-length of the rotor body through

radial openings in the hollow conductors and wedges.

5. Cool ing of St at or Co re

For cooling of the stator core, cold gas is admitted

to the individual frame compartments via separate

cooling gas ducts.

From these frame compartments the gas then flows

into the air gap through slots in the core where it absorbs


15/447

2.1-1100-10550/2

0209E

the heat from the core. To dissipate the higher losses in

the core ends, the cooling gas slots are closely spaced

in the core end sections to ensure effective cooling.

These ventilating ducts are supplied with cooling gas

directly from the end winding space. Another flow path

is directed from the stator end winding space past the

clamping fingers between the pressure plate and core

end section into the air gap. A further flow path passes

into the air gap along either side of the flux shield.

All the flows mix in the air gap and cool the rotor

body and stator bore surfaces. The gas is then returned

to the coolers via the axial-flow fan. To ensure that the

cold gas directed to the exciter end cannot be directly

discharged into the air gap, an air gap choke is arranged

within the range of the stator end winding cover and the

rotor retaining ring at the exciter end.

6. Primary Cool ing water Circui t in the Generator

The treated water used for cooling of the stator

winding phase connectors and bushings is designated

as primary water in order to distinguish it from the

secondary coolant (raw water, condensate, etc.). The

primary water is circulated in a closed circuit and

dissipates the absorbed heat to the secondary cooling

water in the primary water cooler. The pump is supplied

with hot primary water from the primary water tank and

delivers the water to the generator via the coolers. The

cooled water flow is divided into two flow paths as

described in the following paragraphs.

Flow path 1 cools the stator windings. This flow

path first passes to a water manifold on the excitor end

of the generator and from there to the stator bars via

insulated hoses. Each individual bar is connected to the

manifold by a separate hose. Inside the bars the cooling

water flows through hollow strands. At the turbine end,

the water is passed through similar hoses to another

water manifold and then returned to the primary water

tank. Since a single pass water flow through the stator

is used, only a minimum temperature rise is obtained for

both the coolant and the bars. Relative movements due

to different thermal expansions between the top and

bottom bars are thus minimized.

Flow path 2 cools the phase connectors and

bushings. The bushings and phase connectors consist

of thick-walled copper tubes through which the cooling

water is circulated. The six bushings and the phase

connectors arranged in a circle around the stator end

winding are hydraulically interconnected so that three

parallel flow paths are obtained. The primary water enters

three bushings and exits from the three remaining

bushings.

The secondary water flow through the primary water

cooler should be controlled automatically to maintain a

uniform generator temperature level for various loads

and cold water temperatures.


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Turbogenerators

General

Note: The cross section may not match with the generator described in this manual

Section A-B

Section E-F


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BHEL,Haridwar

Turbogenerators

General

1. Stat or Fr am e

The stator frame consists of a cylindrical section

body and two end shields which make the stator gas-

tight and pressure-resistant.

The stator end shields are joined and sealed to

the stator frame with an O-ring and bolted flange

connection. The stator frame accommodates the

electricity active parts of the stator, i.e., the stator core

and the stator windings. Both the gas ducts and a

large number of welded circular ribs provide for the

rigidity of the stator frame. Ring-shaped supports for

resilient core suspension are arranged between the

circular ribs. The generator cooler is subdivided intocooler sections arranged vertically in the turbine side

stator end shield. In addition, the stator end shields

contain the shaft seal and bearing components. Feet

are welded to the stator frame and end shields to

support the stator on the foundation. The stator is

firmly connected to the foundation with anchor bolts

through the feet.

2. Stator Core

The stator core is stacked f rom insulated

electrical sheet-steel laminations and mounted in

supporting rings over insulated dovetailed guide bars.

Ax ia l compression of the stator core is obtained by

clamping fingers, pressure plates, and non-magnetic

through-type clamping bolts, which are insulated from

the core. The supporting rings form part of an inner

frame cage. This cage is suspended in the outer frame

by a large number of separate flat springs distributed

over the entire core length. The flat springs are

tangentially arranged on the circumference in sets

with three springs each, i.e. two vertical supportingsprings on both sides of the core and one horizontal

stabilizing spring below the core. The springs are so

arranged and tuned that forced vibrations of the core

resulting from the magnetic field will not be transmitted

to the frame and foundation.

The pressure plates and end portions of the

stator core are effectively shielded against stray

magnetic fields. The flux shields are cooled by flow

of hydrogen gas directly over the assembly.

2.1-1210-10550/1

0209E


Stator


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BHEL,Haridwar

Turbogenerators

General

as pressur iz ing med ium (VPI p rocess) . The

impregnated bars are formed to the required shape

in molds and cured in an oven at high temperature.

The high-voltage insulation obtained is nearly void-

free and is characterized by its excellent electrical,

mechanical and thermal properties in addition to being

fully waterproof and oil-resistant. To minimize corona

discharges between the insulation and the slot wall,

a final coat of semiconducting varnish is applied to

the surfaces of all bars within the slot range. In

addition, all bars are provided with an end corona

protection, to control the electric field at the transition

from the slot to the end winding and to prevent the

formation of creepage spark concentrations.

3. B ar Su pp or t Sy st em

To protect the stator winding against the effects

of magnet ic forces due to load and to ensure

permanent firm seating of the bars in the slots duri ng

operation, the bars are inserted with a top ripple spring

located beneath the slot wedge. The gaps between

the bars in the stator end windings are completely

filled with insulating material which in turn is fully

supported by the frame. Hot-curing conforming fillers

arranged between the stator bars and the support ringensure a firm support of each individual bar against

the support ring. The bars are clamped to the support

ring with pressure plates held by clamping bolts made

from a high-strength insulating material. The support

ring is free to move axially within the stator frame so

that movements of the winding due to thermal

expansions are not restricted.

The stator winding connections are brought out

to six bushings located in a compartment of welded

non-magnetic steel below the generator at the exci ter

end. Current transformers for metering and relaying

purposes can be mounted on the bushings.


Stator Winding

1. Construct ion

Stator bars, phase connectors and bushings are

designed for direct water cooling. In order to minimize

the stray losses, the bars are composed of separately

insulated strands which are transposed by 540 in the

slot portion and bending, the end turns are likewise

bonded together with baked synthetic resin fillers.

The bars consist of hollow and solid strands

distributed over the entire bar cross-section so that

good heat dissipation is ensured. At the bar ends, all

the solid strands are jointly brazed into a connecting

sleeve and the hollow strands into a water box from

which the cooling water enters and exits via tefloninsulating connection between top and bottom bars

is made by a bolted connection at the connecting

sleeve.

The water manifolds are insulated from the stator

frame, permitting the insulation resistance of the

water-filled winding to be measured. During operation,

the water manifolds are grounded.

2. Micalastic High-Voltage Insulation

High-voltage insulation is provided according to

the proven Micalastic system. With this insulatingsystem, several half-overlapped continuous layers of

mica tape are applied to the bars. The mica tape is

built up from large area mica splittings which are

sandwiched between two polyester backed fabric

layers with epoxy as an adhesive. The number of

layers, i.e., the thickness of the insulation depends

on the machine voltage. The bars are dried under

vacuum and impregnated with epoxy resin which has

very good penetrat ion propert ies due to i ts low

viscosity. After impregnation under vacuum, the bars

are subjected to pressure, with nitrogen being used

2.1-1230-10550/1

0209 E


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BHEL,Haridwar

Turbogenerators

General

1. Rotor Shaft

The rotor shaft is a single-piece solid forging

manufactured from a vacuum casting. Slots for insertion

of the field winding are milled into the rotor body. The

longitudinal slots poles are obtained. The rotor poles are

designed with transverse slots to reduce twice system

frequency rotor vibrations caused by deflections in the

direction of the pole and neutral axis.

To ensure that only high-quality forging is used,

strength tests, material analysis and ultrasonic tests are

performed during manufacture of the rotor.

After complet ion, the rotor is balanced in various

planes at different speeds and then subjected to anoverspeed test at 120% of rated for two minutes.

2. Ro tor Wi ndi ng

The rotor winding consists of several coils which

are inserted into the slots and series connected such

that two coil groups form one pole. Each coil consists of

several series connected turns, each of which consists

of two half turns which are connected by brazing in the

end section.

The rotor winding consists of si lver-bearing

deoxidized copper hollow conductors with two lateralcooling ducts. L-shaped strips of laminated epoxy glass

fiber fabric with Nomexfiller are used for slot insulation.

The slot wedges are made of high-conductivity material

and extend below the shrunk seat of the retaining ring.

The seat of the retaining ring is silver-plated to ensure a

good electrical contact between the slot wedges and

rotor retaining rings. This system has long proved to be

a good damper winding.

3. Retai ni ng Ri ng s

The centrifugal forces of the rotor end windings are

contained by single-piece rotor retaining rings. The

retaining rings are made of non-magnetic high-strength

steel in order to reduce stray losses. Each retaining ring

with its shrink-fitted insert ring is shrunk onto the rotorbody in an overhung position. The retaining ring is

secured in the axial position by a snap ring.

4. Fi el d Co nn ec ti on s

The field current is supplied to the rotor winding

through radial terminal bolts and two semicircular

conductors located in the hollow bores of the exciter and

rotor shafts. The field current leads are connected to

the exciter leads at the exciter coupling with

mul t i con t ac t plug- in contact which al low for

unobstructed thermal expansion of the field currentleads.

2.1-1300-10550/1

0209E


Rotor


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BHEL,Haridwar

Turbogenerators

General

1 Cooler

2 Stator end shield

Fig.1 Arrangement of Hydrogen Cooler

1 2

2.1-1440-10550/1

0209E

The hydrogen cooler is a shell and tube type heat

exchanger which cools the hydrogen gas in the

generator. The heat removed from the hydrogen is

dissipated through the cooling water. The cooling water

flows through the tubes, while the hydrogen is passed

around the finned tubes.

The hydrogen cooler is subdivided into identical

sections which are vertically mounted in the turbine-end

stator end shield. The cooler sections are solidly bolted

to the upper half stator end shield, while the attachment

at the lower water channel permits them to move freely

to allow for expansion.

The cooler sections are parallel-connected on their

water sides. Shut-off valves are installed in the linesbefore and after the cooler sections. The required cooling

water flow depends on the generator output and it is

adjusted by control valves on the hot water side.

Controlling the cooling water flow on the outlet side

ensures an uninterrupted water flow through the cooler

sections so that proper cooler performance will not-be

impaired.


Hydrogen Cooler


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BHEL,Haridwar

Turbogenerators

General

1 Connection for shaft lift oil

2 Thermocouple

3 Bearing sleeve

Fig.1 Bearing

The sleeve bearings are provided with hydraulic

shaft lift oil during start-up and turning gear operation.

To eliminate shaft currents, all bearings are insulated

from the stator and base plate, respectively. The

temperature of the bear ings is moni tored wi th

thermocouples embedded in the lower bearing sleeve

so that the measuring points are located directly below

the babbit t. Measurement and any required recording

of the temperatures are performed in conjunction with

the turbine supervision. The bearings have provisions

for f i t t ing v ibrat ion p ickups to moni tor bear ing

vibrations.

1 2 3


Bearings

2.1-1450-10550/1

0209 E


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BHEL,Haridwar

Turbogenerators

General

The points where the rotor shaft passes through

the stator casing are provided with a radial seal ring.

The seal ring is guided in the seal ring carrier which isbolted to the seal ring carrier flange and insulated to

prevent the flow of shaft currents. The seal ring is lined

with babbitt on the shaft journal side. The gap between

the seal ring and the shaft is sealed withseal oil on

hydrogen side and air side. The hydrogen side seal oil

is supplied to the seal ring via an annular groove in the

seal guide. This seal oil is fed to the hydrogen side

annular groove in the seal ring and from there to the

sealing gap via several bores uniformly distributed on

the circumference. The air side seal oil is supplied to

13 Annular groove for air side seal oil

14 Babbit

15 Seal ring

16 Annular groove for pressure oil

17 Oil wiper ring (air side)

18 Seal oil groove

the sealing gap from the seal ring chamber via radial

bores and the air side annular groove in the seal ring.

To ensure effective sealing, the seal oil pressures in theannular gap are maintained at a higher level than the

gas pressures within the generator casing. The air side

seal oil pressure is set at slightly higher than the

hydrogen side seal oil pressure. The hydrogen side seal

oil is returned to the seal oil system through ducts below

the bearing compartments. The oil drained on the air

side is returned to the seal oil storage tank together with

the bearing oil.

On the air side, pressure oil is supplied laterally to

the seal ring via an annular groove. This ensures free

movement of the seal ring in the radial direction.

Fig.1 Shaft Seal

1 Seal ring carrier flange

2 Seal

3 Insulation

4 Seal ring chamber

5 Inner labyrinth ring

6 Seal strip

7 Rotor shaft

8 Oil wiper ring (H2side)

9 Seal ring carrier

10 Annular groove for hydrogen side seal oil

11 Seal oil inlet bore (H2side)

12 Annular groove for hydrogen side seal oil

2.1-1460-10550/1

0209 E


Shaft Seals


23/447

BHEL,Haridwar

Turbogenerators

General

1 Beari ng Oi l Sy stem

The generator and exciter bearings are connected

to the turbine lube oil supply.

2 Seal Oil System

2.1 Const ruc tion

The shaft seals are supplied with seal oil from two

seal oil circuits which consist of the following principal

components.

Hydrogen Side Seal Oil Circuit :

Seal oil tank Seal oil pump

Oil cooler 1

Oil cooler 2

Seal oil filter

Differential pressure valve C

Pressure equalizing valve TE

Pressure equalizing valve EE.

Air Side Seal Oil Circuit :

Seal oil storage tank

Seal oil pump 1 Seal oil pump 2

Standby seal oil pump

Oil cooler 1

Oil cooler 2

Seal oil filter

Differential pressure valve A1

Differential pressure valve A2

2.2 Hydrogen Side Seal Oil Circuit

The seal oil drained towards the hydrogen side is

collected in the seal oil tank. The associated seal oil

pump returns the oil to the shaft seals via a cooler and

filter. The hydrogen side seal oil pressure required

downstream of the pump is controlled by differential

pressure valve C according to the preset reference value,

i.e. the preset difference between air side and hydrogen

side seal oil pressures.


Oil supply for Bearings and Shaft Seals

2.1-1510-10550/1

0209E

The hydrogen side seal oil pressure required at the

seals is controlled separately for each shaft seals by

respective pressure equalizing valves, according to the

preset pressure difference between the hydrogen side

and air side seal oil.

Oil drained from the hydrogen side is returned to

the seal oil tank via the generator pre-chambers. Two

float-operated valves keep the oi l level at a

predetermined level, thus preventing gas from entering

the suction pipe of the seal oil pump (hydrogen side).

The low level float-operated valve compensates for the

low oil level in the tank by admitting oil from the air side

seal oil circuit. The high level float-operated valve drains

excess oil into the seal oil storage tank. The hydrogenentrapped in the seal oil comes out of the oil in the seal

oil storage tank and is extracted by the bearing vapor

exhauster for being vented to the atmosphere above the

power house roof. During normal operation, the high level

float-operated drain valve is usually open to return the

excess air side seal oil, which flowed to the hydrogen

side via the annular gaps of the shaft seals, to the air

side seal oil circuit.

2.3 Air Side Seal Oil Circuit

The air side seal oil is drawn from the seal oil

storage tank and delivered to the seals via a cooler andfilter by seal oil pump 1. In the event of its failure, seal

oil pump 2 automatically takes over the seal oil supply.

Upon failure of seal oil pump 2, the standby seal oil pump

is automatically started and takes over the seal oil supply

to the shaft seals. In the event of a failure of the seal oil

pump of the hydrogen side seal oil circuit, the seal oil is

taken from the air side seal oil circuit.

The air side seal oil pressure required at the seals

is controlled by differential pressures valve A1 according

to the preset value, i.e. the required pressure difference

between seal oil pressure and hydrogen pressure. In the

event of a failure, i.e. when the seal oil for the seals is

obtained from the standby seal oil pump, differential

pressure valve A2 takes over this automatic control

function.

The seal oil drained from the air side of the shaft

seals is directly returned to the seal oil storage tank.


24/447

BHEL,Haridwar

Turbogenerators

General

Seal Oil System

(Simplified Diagram)

2.1-1511-10550/1

0209 E

Hydrogen side seal oil

Air side seal oil

Pressure oil for seal ring relief

Hydrogen

Hydrogen side seal oil circuit

7 Generator Prechamber

8 Pressure equalizing control valve

9 Seal oil tank

10 Seal oil filter

11 C valve

12 Seal oil cooler

13 Seal oil pump

Air side seal oil circuit

1 Seal ring

2 Seal oil storage tank

3 Seal oil pump

4 A valve

5 Seal oil cooler

6 Seal oil filter


25/447

BHEL,Haridwar

Turbogenerators

General

1 General

The gas sys tem conta ins a l l equ ipment

necessary for filling the generator with CO2, hydrogen

or air and removal of these media, and for operation

of the generator filled with hydrogen. In addition, the

gas system includes a nitrogen (N2) supply. The gas

system consists of :

H2supply CO2supply N2supply Pressure reducers

Pressure gauges Miscellaneous shutoff valves Purity metering equipment Gas dryer CO2flash evaporator Flowmeters

2 Hydrogen (H2) Supply

2 .1 Genera to r Casing

The heat losses arising in the generator are

dissipated through hydrogen. The heat dissipating

capacity of hydrogen is eight times higher than thatof air. For more effective cooling, the hyd rogen in the

generator is pressurized.

2.2 Pr imary Water Tank

A nit rogen envi ronment is maintained above the

pr imary water in the pr imary water tank for the


Gas System

2.1-1520-10550/1

0209E

following reasons.

To prevent the formation of a vacuum due todifferent thermal expansions of the primary water& tank.

To ensure that the primary water in the pumpsuction line is at a pressure above atmospheric

pressure so as to avoid pump cavitation.

To ensure that the primary water circuit is at apressure above atmospheric pressure so as to

avoid the ingress of air on occurrence of a leak.

3 Car bo n Di ox id e (CO2) Supply

As a precaution against explosive hydrogen air

mixtures, the generator must be filled with an inert

gas (CO2) prior to H

2filling and H

2 removal.

The generator must be filled with CO2until it is

positively ensured that no explosive mixture will form

during the subsequent filling or emptying procedures.

4 Co mp res sed Ai r Su pp ly

To remove CO2from the generator, compressed

air is to be admitted into the generator.

The compressed air must be clean and dry. For

this reason, a compressed air filter is installed in the

filter line.

5 Nit rogen (N2) Supply

Nitrogen is required for removing the hydrogen

or air dur ing pr imary water f i l l ing and emptying

procedures.


26/447

BHEL,Haridwar

Turbogenerators

General

Gas System

Simplified Diagram

2.1-1521-10550/1

0209 E

1 H2bottle

2 H2pressure reducer

3 N2

bottle

4 N2pressure reducer

5 Primary water tank

6 Pressure controller

7 Upper generator gas header

8 Lower generator gas header

9 Gas drier heater

10 Gas drier fan

11 Gas drier chamber

12 CO2

/H2

purity transmitter

13 Dehydrating filter for measuring gas

14 Pressure reducer for measuring gas

15 Compressed air hose

16 Compressed air filter

17 CO2flash evaporator

18 CO2bottle


27/447

BHEL,Haridwar

Turbogenerators

General

1 General

The pr imary water requ i red fo r coo l ing is

circulated in a closed circuit by a separate pump. To

ensure uninterrupted generator operation, two full-

capacity pumps are provided. In the event of a failure

of one pump, the standby pump is immediately ready

for service and cuts in automatically. Each pump is

driven by a separate motor.

Al l va lves , pipes and inst ruments coming in to

contact with the primary water are made from stainless

steel material.

The pr imary water system consists of the

following principal components :

Primary water tank Primary water pumps Cooler Primary water filter Fine filter Ion exchanger Alkalyser unit

As i l lustra ted in th e diagra m, the pri mar y wate r

admitted to the pump from the tank is first passed via

the cooler and fine filter to the water manifold in thegenerator interior and then to the bushings. After

having performed its cooling function, the water is



2.1-1530-10550/1

0209E

returned to the primary water tank. The gas pressure

above the water level in the primary water tank is

maintained constant by a pressure regulator.

2 Pri mary Wat er Tan k

The primary water tank is located on top of the

stator frame on an elastic support, thus forming the

highest point of the entire primary water circuit in

terms of static head.

3 Pr imar y Wat er Tr ea tmen t Sys t em

The direct contact between the primary water andthe high-voltage windings calls for a low conductivity

of the primary water. During operation, the electrical

conductivity should be maintained below a value of

approximately 1 mho/cm. In order to maintain such

a low conductivity i t is necessary to provide for

continuous water treatment. During operation, a small

quantity of the primary water flow should therefore

be continuously passed through the ion exchanger

located in the bypass of the main cooling circuit. The

ion exchanger resin material required replacement

during operation of the generator, since with the water

treatment system out of service, the conductivity will

rise very slowly.


28/447

BHEL,Haridwar

Turbogenerators

General

Primary water circuit, general

Coolant flow : stator winding

Coolant flow : main bushings and phase connectors

Water treatment

Waste gasHydrogen

7 Bypass line

8 Cooling water for stator winding

9 Ion exchanger

10 Cooling water for main bushings and phase connectors

11 Teflon hose

12 Cooling water manifold

13 Alkaliser unit

1 Primary water tank

2 Pressure regulator

3 Waste gas to atmosphere

4 Pump

5 Cooler

6 Filter


(Simplified Diagram)

2.1-153110550/1

0209 E


29/447

BHEL,Haridwar

Turbogenerators

Description

Technical Data

General and Electrical Data

2.1-1810-10550/1

0209E

General

Project name NCTPP DADRI Stage II unit I &2

Generator Type THDF 115/59

Main Exciter Type ELR 70/90-30/6-20

Pilot exciter Type ELP 50/42-30/16

Year of manufacture 2008-09

Rated Data and Outputs Turbogenerator Main Exciter Pilot Excitor

Apparent power 577MVA - 65 kVA

Active power 490MW 3780 kW -

Current 15.85 kA 6300 A 195 A

Voltage 21 kV + 1.05 kV 600 V 220 V + 22 V

Speed 50s-1 50s-1 50 s-1

Frequency 50 Hz - 400 Hz

Power factor 0.85 (lag) - -

Inner connection of stator winding YY - -

H2pressure 3.5 bar (g) - -

Cont. perm. unbalanced Load 8% - -

Rated field current for rated output 3973 A - -

Rated field voltage 334 V - -

The machines are designed in conformity with IEC-34 and should be operated according to these specifications.

The field current is no criterion of the load carrying capacity of the turbogenerator.

Resistance in Ohms at 20C Turbogenerator Main Excitor Pilot Excitor

U-X 0.001445 ohms U-0 0.002518 ohms

Stator Winding V-Y 0.001445 ohms F1-F2 0.592 ohms V-0 0.002538 ohms

W-Z 0.001445 ohms W-0 0.002529 ohms

U-V 0.00046 ohms

Rotor Winding F1-F2 0.06700 ohms U-W 0.00046 ohms

V-W 0.00046 ohms

Rectifier Wheel

Number of fuses 30

per rectifier wheel (800 V, 800 A)

-

Fuse, resistance approx. 150 ohms -

Number of diodes

per rectifier wheel 60-

Action Required:

Number of fuses blown per 2 fuses Switch off field forcing

bridge arm and rectifier wheel 3 fuses Shutdown turbine-generator, replace

fuses and diodes.


30/447

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Mechanical Data

2.1-1820-10550/1

0209 E

Torques, Cri t ical Speed etc. Torques and Units

Speeds

Maximum short-circuit torque of stator at

line-to-line single-phase short-circuit 14585 knm

Moment of inertia of generator rotor shaft 10000 kgm2

hhhhh1 864

Critical speed (calculated) hhhhh

2 2388 RPM

(Generator + Exciter coupled) hhhhh3 4680

Generator Volume and Fi l l ing Quant i t ies Volume Units

Generator volume (gas volume) 80 m3

CO2filling quantity*** 160 m3(s.t.p.)*

H2filling quantity (to 3.5 bar)** 480 m3(s.t.p.)*

Weights Weight units

Stator with end shields and coolers 360000 kg

Shipping weight of stator 265000 kg

Stator end shield, upper part TE 22066 kg

Stator end shield, upper part EE 6665 kg

Stator end shield, lower part, TE 24200 kg

Stator end shield, lower part, EE 9950 kg

Rotor 68000 kg

H2cooler section, including water channels 1770 kg

Gas dryer 950 kg

One seal oil cooler (air side) 320 kg

One seal oil cooler (H2side) 250 kg

One primary water cooler 90 kg

Exciter rotor 7550 kg

Component Material Component Material

Rotor shaft 26NiCrMoV145 Electrical sheet-steel 1.5 W/Kg at 1 Tesla 0.5 mm TK

Rotor copper CuAg0.1PF25 Stator copper E-Cu58F20

Rotor wedges CuCoBeZr Bearing babbitt Babbitt V 738

Retaining rings X8CrMnN1818K Seal rings babbitt Babbitt V 738

Damper wedges CuAg0.1F25

* s.t.p. = Standard temperature and pressure, 0oC and 1.013 bar to DIN 1343

** Volume required with unit at standstill. With the unit on the turning gear, the volume will be higher.

*** CO2 quantity kept on stock must always be sufficient for removal of the existing hydrogen filling.

All values are approximate.


31/447

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Seal Oil System

2.1-1825-10550/1

0209E

Seal oil pumps -1,2 (Air Side) MKW 11 AP 001 andMKW 21 AP 001

Kind of pump

Type

Capacity

Discharge pressure

Pump motor

Rating

Voltage/ frequency

Current

Speed

Type of enclosure

Nos.

Seal oil pump -3 ( Air side) MKW 31 AP 001

Kind of pump

Type

Capacity

Discharge pressure

Pump motor

Rating

Voltage

Current Armature

Speed

Type of enclosure

Nos.

Seal oil pump (H2side) MKW 13 AP 001

Kind of pump

Type

Capacity

Discharge pressure

Pump motor

Rating

Voltage/ frequency

Current

Speed

Type of enclosureNos.

Seal oil filters MKW 51 BT 001, MKW 51 BT 002,

MKW 53 BT 001 & MKW 53 BT 002

Kind of filter

Type

Volumetric flow rate

Degree of filtration

Pressure drop across filter

Nos. for air side

Nos. for H2side

Three Screw pump

T3S - 52/54

258 LPM

12Kg/Cm2

CGL, ND132M

7.5 KW

415V, 3 Ph AC 50Hz

13.6 A

1455 RPM

TEFC, IP55

2x100% capacity

Three Screw pump

T3S - 52/54

258 LPM

12 Kg/cm2

CGL, AFS 225L

8.5 KW

220 V DC

67 A

1450 RPM

TEFC , IP551x100% capacity

Three Screw pump

T3S - 52/46

130 LPM

12 kg/cm2

CGL, ND 132M

4 KW

415V, 3 Ph AC 50Hz

9.3 A

945 RPM

TEFC, IP55

1x100% capacity

Strainer-type filter

2.32.9 Ma (M/s Boll & Kirch)

4.16 dm3/s

100 microns

0.3 bar with clean filter *

2x100% capacity

2x100% capacity

* 1.2 bar with 100% blockage

Design Data


32/447

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Gas System

2.1-1826-10550/1

0209 E

CO2vapou riser MKG 51 AH 001

Rating

Voltage

Heat transfer liquid

Volume of heat transfer liquid

Hole in orifice

Relief valve on high-pressure side

Relief valve on low-pressure side

Nos.

Refrigeratio n type gas drier

Rating and parameters

Compr essed air fi lter MGK 25 BT 001

Volume of activated carbon

Service hours

Throughput

Nos.

18 kW

415V, 3 Ph AC 50Hz

HYTHERM 500 (M/s HPCL)

25 dm3

2.8 mm

175 bar

8 bar

2x100% capacity

As per sub-supplier s manual

3 dm3

approx. 1500 h to 2000 h

80 m3/hr at 8 bar

1x100% capacity

Design Data


33/447

BHEL,Haridwar

Turbogenerators

Description

Technical Data


2.1-1827-10550/1

0209 E

Design Data

Primary water pumps MKF12AP001 and MKF22AP001

Kind of pump Centrifugal pump

Type CZ 65-250 (M/s Sulzer Pumps)

Speed 2950 RPM

Capacity 70 m3/Hr

Discharge head 80 m

Pump motor ND200 L (M/s Crompton Greaves Ltd)

Rating 37KW

Voltage 415V, 3 Ph AC 50Hz

Frequency 50 Hz

Speed 2950 RPMType of enclosure TEFC

Nos. 2x100% capacity

Main fi lters MKF 52 BT 001 and MKF 52 BT 002

Kind of filter Strainer-type filter with magnet bars

Type 1.53.1 (M/s Boll & Kirch)

Volumetric flow rate 25 dm3/s max.

Degree of filtration 150 mm

Pressure drop across filter 0.1 bar with clean filter

1.2 bar with 100% fouling


Fine fil ter MKF 60 BT 001

Kind of filter 1 plug. 1 cartridge

Type 1.55.1 (M/s Boll & Kirch)

Volumetric flow rate 0.42 dm3/s max.

Pressure drop across filter 0.15 bar with clean filter

1.2 bar with 100% fouling


Ion exchanger MKF 60 BT 001

Volume 83 litres

Resin Lewatit

Resin volume 56 litres (45 kg)



34/447


35/447

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Excitation System

2.1-1829-10550/1

0209 E

A-wheel (negat ive polarity )

No./Type of diodes

No./Type of fuses

Resistance/voltage/current per fuse

No. of RC networks

B-wheel (positive polarity)

No./Type of diodes

No./Type of fuses

Resistance/voltage/current per fuseNo. of RC networks

Stroboscope

Type

Voltage

Frequency

No. of stroboscope

Exciter air dryer

Type

Rating

Voltage

Frequency

Adsorption air flow rate

Regeneration air flow rate

No. of dryer

60 Nos./BHdL 1220 (BHEL EDN,Bangalore make)

30 Nos./3NC 9 538

approx. 150 , 800 V, 800 A

6 Nos.

60 Nos./BHdL 1320(BHEL EDN,Bangalore make)

30 Nos./3NC 9 538

approx. 150 , 800 V, 800 A6 Nos.

LX5-30/36-2

240 V

50/60 Hz

1 No.

BA-1.5 A (M/S BRYAIR MAKE)

4,6 kW

230 V

50 Hz

120 m3/h

35 m3/h

1 No.

Design Data


36/447

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Cooler Data

Note:The specified cooler data refer to max. cooling water inlet temperatures. During operation the operatingvalues of the coolers may deviate from above design data.

Materials and PressuresUnits

Design Data for One Seal Oil Cooler (H2Side)

Drg. No. 0-165-03-70005 C (1 x100% )Materials and PressuresUnits

3.5 Bar (g)

33 m3/s

4640 kW

45 C

72 C

700 Pa

540 m3/hr

38 C

45.4 C3.0 MWC

Design Data for the H2Cooler,

Drg. No. 0-166-01-70006C(4 x 25% each)

Materials

Fins Copper

Tubes 90/10 Cu-Ni

Tubesheets Carbon steel

Water channels Carbon steel

Pressures (Tube Side)

Design pressure 10 kg/cm2

Test pressure 15 kg/cm2

Hydrogen pressure

Gas flow (Total)

Heat dissipating capacity (Rated)

Cold gas temperature

Hot gas temperature (max.)

Gas pressure drop (approx.)

Cooling water flow (Total for 4 sections)

Cooling water inlet temperature (design)

Water outlet temperatureWater pressure drop

Design Data for One Seal Oil Cooler (Air Side)

Drg. No. 0-165-03-70006 C(1 x 100% )Units Mater ials and Pressures

Oil flow


Oil inlet temperature

Oil Outlet temperature

Oil pressure drop (approximate)

Cooling water flow


Water outlet temperature

Water pressure drop (approximate)*

15 m3/hr

140 kW

70 C

50 C

0.833 Bar

35 m3/hr

38 C

41.4 C

6.8 mWC

Materials

Tubes Admiralty Brass



Cooling water Pressures



Oil Side Pressures

design pressure 16 kg/cm2


Oil flow


Oil inlet temperature

Oil outlet temperature

Oil pressure drop (approximate)

Cooling water flow


Water outlet temperature

Water pressure drop (approximate)*

7.8 m3/hr

90 kW

70 C

50 C

0.85 Bar

22 m3/hr

38 C

41.5 C

7.1 mWC

Materials

Tubes Admiralty Brass



Cooling Water Pressures



Oil Side Pressures



2.1-1830-10550/1

0209 E


37/447


65 m3/hr

1715 kW

71.7 C

49 C

1160 mBar

250 m3/hr

38 C

43.9 C

2.0 mWC

Design Data for the Primary Water

Cooler, Drg. No. 0-165-41-70013 C

(2x 100% )

Materials

Shell SS

Tubes SS

Tubesheets SS

Water channels Carbon Steel

Primary Water Side Pressures



Cooling Water Side Pressures



Primary water flow


Primary water inlet temperature

Primary water outlet temperature

Primary water pressure drop

Cooling water flow

Maximum cooling water inlet temperature

Cooling water outlet temperature

Water pressure drop*

* Flange-to-flange of equipment only


1 Bar (g)

15.5 m3/s

500 kW

45 C

74 C

700 Pa

200 m3/hr

38 C40.2 C

3.0 mWC

Design Data for the Exciter Ai r Cooler,Drg. No. 0-166-05-70003C

(2 x 50% each)

Materials

Fins Copper

Tubes 90/10 Cu-Ni



Pressures (Tube Side)



Air pressure

Air flow (Total)


Cold air temperature

Hot air temperature (max.)

Air pressure drop (approx.)

Cooling water flow

Cooling water inlet temperature (design)Water outlet temperature

Water pressure drop*

2.1-1830-10550/2

0209 E


38/447

BHEL,Haridwar

Turbogenerators

Description

2.1-1850-10550/1

0209E

t TECHNICAL DATA

Reactive Capability Curve


39/447

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Load Characteristic of Pilot Exciter

2.1-1860-10550/1

0209 E

PMG Pilot Exciter Characteristic

2 0 0

2 0 5

2 1 0

2 1 5

2 2 0

2 2 5

2 3 0

2 3 5

2 4 0

0 5 0 1 0 0 1 5 0 2 0 0 2 5 0

PMG field current (amps)

PMGVoltage(volts)


40/447

BHEL,Haridwar

Turbogenerators

DescriptionGas Specification

1. Comp res sed Ai r

The compressed air shall be free of-

corrosive contaminants and

hazardous gases, flammable or toxic.

The maximum total oil or hydrocarbon content,

exclusive of non-condensables, shall be as close

to zero (0) w/w or v/v as possible, and under no

circumstances shall it exceed one (1) ppm w/w or

v/v under normal operating conditions.

The compressed air shall be practically free of dust.

The maximum particle size in the air stream shall be

five (5) micrometers.

The oxygen content of the expanded air shall be

between 20 and 21% v/v.

The dew point at line pressure shall be at least 15 K

below the minimum possible generator temperature.

In no case should the dew point at line pressure

exceed 10 C.

The compressed air shall be available at a gauge

pressure between 6 and 9 bar.

Volumetric flow rate: 144 to 216 m3/h.

2. Car bon Diox ide (CO2)

Carbon dioxide shall be made available with a purity

99.9 % v/v. The remaining 0.1 % v/v shall be free of

corrosive contaminants: traces of ammonia (NH3) and

sulphur dioxide (SO2) shall not be detectable by

analysis.

If obtained from a central bulk supply, the gas shall be

made available at the following conditions:

Gauge pressure : 1 to 2.5 bar

Temperature : 20 to 30 0C

Volumetric flow rate : 144 to 216 m3/h.

3 Hydrogen (H2)

The hydrogen gas shall be made available with a purity

99.9% v/v. The remaining 0.1 % v/v shall be free of

corrosive contaminants: traces of ammonia (NH3) and

sulphur dioxide (SO2) shall not be detectable byanalysis.

If obtained from a central bulk supply, the hydrogen

gas shall be made available at the following conditions:

Gauge pressure : 8 to 9 bar

Volumetric flow rate : 144 to 216 m3/h.

4 Nitrogen (N2)

The nitrogen gas shall be made available with a purity

of 99.99 % v/v.

Contaminants (O2, H

2O): not applicable

The remaining 0.01% v/v shall be free of corrosive

contaminants; traces of ammonia (NH3) and sulphur

dioxide (SO2) shall not be detectable by analysis.

1)s.t.p. = standard temperature and pressure. 00C and 1.013 bar to DIN 1343.

The gauge pressures and temperatures indicated are those at the inlets of the generator gas supply units.

2.1-1883-10550/1

0209E


41/447


42/447

BHEL,Haridwar

Turbogenerators

Description Specification for

Ion Exchange Resins

1. General

The primary water must have a low condictivity since it

comes into direct contact with the high-voltage winding.

To maintain a low conductivity the primary water requires

continuous treatment. This is achieved by continuously

passing a small primary water volume flow through a mixed

bed ion exchanger arranged in the bypass of the main

cooling circuit. The ion exchange resins must be replaced

at certain intervals. The resins may be replaced while the

generator is in operation, since with the water treatment

system out of service the conductivity will continue to rise

only very slowly.

2. Res in Sp ec if ic at io n

The resins should contain no impurities or soluble

substances having a detrimental effect on the materials

used in the primary water circuit and thus on the availability

of the generator.

Our recommendation to use Lewatit ion exchange

resins is based on many years of service experience and

the close cooperation between the resin supplier and many

power plant operators as well as the high quality standard

of the resins.

The initial charge of the mixed-bed ion exchanger

consists of the following types of resins.

Lewatit S 100 KR/H/chloride-free

Lewatit M 500 KR/OH/chloride-free

When replacing the resins, use either the above types

or resins available from other manufacturers which must

comply with the specification below.

Cation exchanger Anion exchanger

(Lewatit S100KR/H/chlori de-free) (Lewatit M500 KR/OH/chlorid e-free)

Functional group Strongly acidic Very strongly basic

Grain shape Beads Beads

Particle size (0.3 - 1.25) mm (0.3 - 1.25) mm

Bulk density of swollen resin (800 - 900) g/dm3 (670 - 750) g/dm3

Resin form H-ions OH-ions

Specific load up to 40 dm3/h dm3 40 dm3/h dm3

Total capacity of swollen resin (1.9 - 2.2) mol/dm3 (1.1 - 1.6) mol/dm3

Useful capacity min. 50 gCaO/dm3 16 gCaO/dm3

Chloride content up to 50 mg/dm3 50 mg/dm3

Thermal stability up to 1200C 700C

Stability in pH range Unlimited Unlimited

Shelf life min.

(in original packing 5 years 3 yearsat temperatures of +1oC to +40oC

2.1-1887-10550/1

0209 E


43/447

BHEL,Haridwar

Turbogenerators

Description

A lso ref er to the fo l lowing in fo rmat ion

[1] 2.1-7341 Alkalizer Unit for Primary Water Circuit

[2] 2.1-1885 Primary Water Specification

Despite the use of oxygen-poor water, corrosion of

copper in the primary water circuits of water-cooled

windings, cannot be completely avoided, and in isolated

cases the corrosion products can reduce the cross-

sectional flow area of the water distribution system.

The sever ity of the corrosion attack can be

substantially reduced by alkalizing the oxygen-poor water.

In addition, the system becomes less susceptible to

disturbances resulting from air in-leakage.

Operating the generator with alkal ine water at pH 8 to

9 will improve the reliability and availability of the turbine

generator.

For operation of the alkalizer unit [1 ] , dilute sodium

hydroxide for continuous injection into the primary water

circuit and lime are required.

1 Sod ium Hydrox ide So lut ion

The sodium hydroxide solution should have a

concentration of 10 to 20 g of NaOH per dm3.

Sodium hydroxide solution should be prepared from :

Caustic Soda [NaOH] of P.A. quality, containing.

NaOH : > 98%

Carbonates [Na2CO

3] : < 1%

Water in conformity with the primary water

specification[2] .

2 L ime

A lime filter to be provided in the NaOH tank vent serves

to bind the carbon dioxide (CO2) contained in the inlet air in

order to prevent the formation of carbonates in the sodium

hydroxide solution.

The lime filter consists of equal parts of sodium

hydroxide (NaOH) and calcium hydroxide (Ca(OH)2). This

mixture is commercially available and known as soda lime.

Addi t ive Spec i f icai ton

for Al kal izer Unit

2.1-1888-10550/1

0209 E


44/447

BHEL,Haridwar

Turbogenerators

Description

2.1-2100-10550/1

0209 E

Stator Frame

To facilitate manufacture, erection and transport, the

stator consists of the following main components:

Stator frame

End shields

Bushing compartment

The stator frame with flexible core suspension

components, core, and stator winding is the heaviest

component of the entire generator. A rigid frame is

required due to the forces and torques arising during

operation. In addition, the use of hydrogen for the

generator cooling requires the frame to be pressure-

resistant up to an internal pressure of approximately 10

bar (130 psi g).The welded stator frame consists of the cylindrical

frame housing, two flanged rings and axial and radial

ribs. Housing and ribs within the range of the phase

connectors of the stator winding are made of non-

magnetic steel to prevent eddy current losses, while the

remaining frame parts are fabricated from structural

steel.

1 2 3 4

1 Stator End shield 2 Bushing compartment

3 Frame housing 4 Stator foot

Fig:1 Stator frame

The arrangement and dimensionally of the ribs are

determined by the cooling gas passages and the required

mechanical strength and stiffness. Diminishing is also

dictated by vibrational considerations, resulting partly in

greater wall thickness then required, from the point of

view of mechanical strength. The natural frequency of

the frame does not correspond to any exciting frequency.

Two lateral supports for flexible core suspension in

the frame are located directly adjacent to the points

where the frame is supported on the foundation. Due to

the rigid design of the supports and foot portion, the

forces due to weight and short-circuits will not result in

any over-stressing of the frame.

Manifolds are arranged inside the stator frame at the

bottom and top for filling the generator with CO2and H

2

. The connections of the manifolds are located side by

side in the lower part of the frame housing.

Addi tional openings in the housing, which are sealed

gastight by pressure-resistant covers, afford access to

the core clamping flanges of the flexible core suspension

system and permit the lower portion of the core to be

inspected. Access to the end winding compa

o&m manual 500 mw turbogenerator

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