ATraining report

On

At BHEL HARIDWAR

Submitted in partial fulfillment of requirements for the degree of

Bachelor of Technology In

Mechanical Engineering

Submitted By: Submitted To:ABHINAV BARTHWAL MOHD.YUNUS SHEIKH

B.Tech. (Final Year) Sr. Lecturer

Department of Mechanical EngineeringGOVT. ENGINEERING COLLEGE, BIKANER

RAJASTHAN TECHNICAL UNIVERSITY, KOTA2012-13

“TURBINE MANUFACTURING”

[i]

ACKNOWLEDGEMENT

“Inspiration and motivation have always played a key role in the success of anyventure.”

Success in such comprehensive report can’t be achieved single handed. It is theteam effort that sail the ship to the coast. So I would like to express my sincere thanks tomy mentor MR. A.K. KHUSHWAHA Sir.

I am also grateful to the management of Bharat Heavy Electrical limited (BHEL),

Haridwar for permitting me to have training during June 2th to July 2th, 2012.

It gives me in immense pleasure to express my gratitude to the department of

Mechanical Engineering for their prudent response in course of completing my training

report. I am highly indebted to, MR. MOHD. YOUNIS SHEIKH, their guidance and

whole hearted inspiration; it has been of greatest help in bringing out the work in the

present shape. The direction, advice, discussion and constant encouragement given by

them has been so help full in completing the work successfully

[ii]

INDEX

S.R. NO. TOPIC PAGE NO.

INTRODUCTION 1

1. BHEL 2 – 17

1.1.OVERVIEW 2

1.2.WORKING AREAS 3

1.2.1 POWER GENERATION 3

1.2.2 POWER TRANSMISSION &DISTRIBUTION 3

1.2.3 INDUSTRIES 4

1.2.4 TRANSPORTATION 5

1.2.5 TELECOMMUNICATION 5

1.2.6 RENEWABLE ENERGY 5

1.2.7 INTERNATIONAL OPERATIONS 6

1.3 TECHNOLOGY UP GRADATION ANDRESEARCH AND DEVELOPMENT

7

1.3.1HUMAN RESOURCE DEVELOPMENT INSTITUTE 7

1.4 HEALTH, SAFETY AND ENVIRONMENTMANAGEMENT

8

1.4.1 ENVIRONMENTAL POLICY 8

1.4.2 OCCUPATIONAL HEALTH AND SAFETY POLICY 8

1.4.3 PRINCIPLES OF THE "GLOBAL COMPACT" 9

1.5 BHEL UNITS 11

1.6 BHEL HARIDWAR 13

1.6.1LOCATION 13

1.6.2ADDRESS 13

1.6.3 AREA 13

1.6.4 UNITS 14

1.6.5 HEEP PRODUCT PROFILE 16

[iii]

2. STEAM TURBINE 18-21

2.1 INTRODUCTION 18

2.2 ADVANTAGES 20

2.3DISADVANTAGES 21

2.4 STEAM TURBINES THE MAINSTAY OF BHEL 21

3. TYPES OF STEAM TURBINE 22-23

3.1 IMPULSE TURBINE 22

3.2 THE IMPULSE TURBINE PRINCIPLE 22

3.3 REACTION PRINCIPLE 23

3.4 IMPULSE TURBINE STAGING 23

4. TURBINE PARTS 24-25

4.1 TURBINE BLADES 24

4.2 TURBINE CASING 24

4.3 TURBINE ROTORS 25

5. CONSTRUCTIONAL FEATURES OF A BLADE 26-33

5.1 H.P. BLADE PROFILE 26

5.2 CLASSIFICATION OF PROFILES 27

5.3 H.P BLADE ROOTS 28

5.4 L.P BLADE PROFILE 30

5.5 L.P BLADE ROOTS 30

5.6 DYNAMICS IN BLADE 30

5.7 BLADING MATERIALS 33

6. MANUFACTURING PROCESS 34-37

6.1 INTRODUCTION 34

6.2 CLASSIFICATION OF MANUFACTURINGPROCESS

34

6.2.1 PRIMARY SHAPING PROCESSES 35

[iv]

6.2.2 SECONDAY OR MACHINING PROCESSES 36

7. BLOCK-3 LAY-OUT 38

8. CLASSIFICATION OF BLOCK-3 39-42

9. BLADE SHOP 43-45

9.1 TYPES OF BLADES 43

9.2 OPERATIONS PERFORMED ON BLADES 44

9.3 MACHINING OF BLADES 44

9.4 NEW BLADE SHOP 45

10. CONCLUSION 46

[v]

FIGURE INDEX

S.R.NO. TOPIC PAGE NO.

1. SECTIONAL VIEW OF A STEAM TURBINE 18

2. FLOW DIAGRAM OF A STEAM TURBINE 19

3. HIGH PRESSURE BLADE PROFILE 26

4. OVERSPEED AND VACCUM BALANCING TUNNEL 40

5. STEAM TURBINE CASING AND ROTORS IN ASSEMBLING

AREA

42

6. CNC ROTOR TURNING LATHE 42

7. TYPES OF BLADES 43

8. SCHEMATIC DIAGRAM OF A CNC MACHINE 44

9. CNC SHAPING MACHINE 45

[vi]

TABLE INDEX

S.R.NO. TOPIC PAGE NO.

1. BHEL UNITS 12

2. BLOCKS IN HEEP 14

3. SECTIONS IN CFFP 15

4. BLADE ROOTS 29

5. LAYOUT OF BLOCK-3 38

1

INTRODUCTION

BHEL is the largest engineering and manufacturing enterprise in India in the

energy related infrastructure sector today. BHEL was established more than 40 years ago

when its first plant was setup in Bhopal ushering in the indigenous Heavy Electrical

Equipment Industry in India a dream which has been more than realized with a well

recognized track record of performance it has been earning profits continuously since

1971-72.

BHEL caters to core sectors of the Indian Economy viz., Power Generation's &

Transmission, Industry, Transportation, Telecommunication, Renewable Energy,

Defense, etc. The wide network of BHEL's 14 manufacturing division, four power

Sector regional centers, over 150 project sites, eight service centers and 18 regional

offices, enables the Company to promptly serve its customers and provide them with

suitable products, systems and services – efficiently and at competitive prices. BHEL

has already attained ISO 9000 certification for quality management, and ISO 14001

certification for environment management.

The company’s inherent potential coupled with its strong performance make this

one of the “NAVRATNAS”, which is supported by the government in their endeavor to

become future global players.

2

1. BHEL

1.1. OVERVIEW

Bharat Heavy Electricals Limited (B.H.E.L.) is the largest engineering and

manufacturing enterprise in India. BHEL caters to core sectors of the Indian

Economy viz., Power Generation's & Transmission, Industry, Transportation,

Telecommunication, Renewable Energy, Defense and many more.

Established in 1960s under the Indo-Soviet Agreements of 1959 and 1960 in the

area of Scientific, Technical and Industrial Cooperation.

BHEL has its setup spread all over India namely New Delhi, Gurgaon, Haridwar,

Rudrapur, Jhansi, Bhopal, Hyderabad, Jagdishpur , Tiruchirapalli, Bangalore and

many more.

Over 65% of power generated in India comes from BHEL-supplied equipment.

Overall it has installed power equipment for over 90,000 MW.

BHEL's Investment in R&D is amongst the largest in the corporate sector in

India. Net Profit of the company in the year 2011-2012 was recorded as 6868

crore having a high of 21.2% in comparison to last year.

BHEL has already attained ISO 9000 certification for quality management, and

ISO 14001 certification for environment management.

It is one of India's nine largest Public Sector Undertakings or PSUs, known as the

NAVRATNAS or 'the nine jewels'

The power plant equipment manufactured by BHEL is based on contemporary

technology comparable to the best in the world

The wide network of BHEL's 14 manufacturing divisions, four Power Sector

regional centre, over 100 project sites, eight service centre and 18 regional

offices, enables the Company to promptly serve its customers and provide them

with suitable products, systems and services – efficiently

3

1.2. WORKING AREAS

1.2.1. POWER GENERATION

Power generation sector comprises thermal, gas, hydro and nuclear power plant

business as of 31.03.2001, BHEL supplied sets account for nearly 64737 MW or 65% of

the total installed capacity of 99,146 MW in the country, as against nil till 1969-70.

BHEL has proven turnkey capabilities for executing power projects from concept

to commissioning, it possesses the technology and capability to produce thermal sets with

super critical parameters up to 1000 MW unit rating and gas turbine generator sets of up

to 240 MW unit rating. Co-generation and combined-cycle plants have been introduced

to achieve higher plant efficiencies. to make efficient use of the high-ash-content coal

available in India, BHEL supplies circulating fluidized bed combustion boilers to both

thermal and combined cycle power plants.

The company manufactures 235 MW nuclear turbine generator sets and has

commenced production of 500 MW nuclear turbine generator sets.

Custom made hydro sets of Francis, Pelton and Kaplan types for different head

discharge combination are also engineering and manufactured by BHEL.

In all, orders for more than 700 utility sets of thermal, hydro, gas and nuclear have

been placed on the Company as on date. The power plant equipment manufactured by

BHEL is based on contemporary technology comparable to the best in the world and is

also internationally competitive.

The Company has proven expertise in Plant Performance Improvement through

renovation modernization and upgrading of a variety of power plant equipment besides

specialized know how of residual life assessment, health diagnostics and life extension of

plants.

1.2.2. POWER TRANSMISSION & DISTRIBUTION (T & D)

BHEL offer wide ranging products and systems for T & D applications. Products

manufactured include power transformers, instrument transformers, dry type

4

transformers, series – and stunt reactor, capacitor tanks, vacuum – and SF circuit breakers

gas insulated switch gears and insulators.

A strong engineering base enables the Company to undertake turnkey delivery of

electric substances up to 400 kV level series compensation systems (for increasing power

transfer capacity of transmission lines and improving system stability and voltage

regulation), shunt compensation systems (for power factor and voltage improvement) and

HVDC systems (for economic transfer of bulk power). BHEL has indigenously

developed the state-of-the-art controlled shunt reactor (for reactive power management

on long transmission lines). Presently a 400 kV Facts (Flexible AC Transmission System)

project under execution.

1.2.3. INDUSTRIES

BHEL is a major contributor of equipment and systems to industries. Cement,

sugar, fertilizer, refineries, petrochemicals, paper, oil and gas, metallurgical and other

process industries lines and improving system stability and voltage regulation, shunt

compensation systems (for power factor and voltage improvement) and HVDC systems

(for economic transfer of bulk power) BHEL has indigenously developed the state-of-the-

art controlled shunt reactor (for reactive power management on long transmission lines).

Presently a 400 kV FACTS (Flexible AC Transmission System) projects is under

execution. The range of system & equipment supplied includes: captive power plants, co-

generation plants DG power plants, industrial steam turbines, industrial boilers and

auxiliaries. Water heat recovery boilers, gas turbines, heat exchangers and pressure

vessels, centrifugal compressors, electrical machines, pumps, valves, seamless steel

tubes, electrostatic precipitators, fabric filters, reactors, fluidized bed combustion boilers,

chemical recovery boilers and process controls.

The Company is a major producer of large-size thruster devices. It also supplies

digital distributed control systems for process industries, and control & instrumentation

systems for power plant and industrial applications. BHEL is the only company in India

with the capability to make simulators for power plants, defense and other applications.

5

The Company has commenced manufacture of large desalination plants to help

augment the supply of drinking water to people.

1.2.4. TRANSPORTATION

BHEL is involved in the development design, engineering, marketing, production,

installation, maintenance and after-sales service of Rolling Stock and traction propulsion

systems. In the area of rolling stock, BHEL manufactures electric locomotives up to 5000

HP, diesel-electric locomotives from 350 HP to 3100 HP, both for mainline and shunting

duly applications. BHEL is also producing rolling stock for special applications viz.,

overhead equipment cars, Special well wagons, Rail-cum-road vehicle etc., Besides

traction propulsion systems for in-house use, BHEL manufactures traction propulsion

systems for other rolling stock producers of electric locomotives, diesel-electric

locomotives, electrical multiple units and metro cars. The electric and diesel traction

equipment on India Railways are largely powered by electrical propulsion systems

produced by BHEL. The company also undertakes retooling and overhauling of rolling

stock in the area of urban transportation systems. BHEL is geared up to turnkey

execution of electric trolley bus systems, light rail systems etc. BHEL is also diversifying

in the area of port handing equipment and pipelines transportation system.

1.2.5. TELECOMMUNICATION

BHEL also caters to Telecommunication sector by way of small, medium and

large switching systems.

1.2.6. RENEWABLE ENERGY

Technologies that can be offered by BHEL for exploiting non-conventional and

renewable sources of energy include: wind electric generators, solar photovoltaic

systems, solar lanterns and battery-powered road vehicles. The Company has taken up

R&D efforts for development of multi-junction amorphous silicon solar cells and fuel

based systems.

6

1.2.7. INTERNATIONAL OPERATIONS

BHEL has, over the years, established its references in around 60 countries of the

world, ranging for the United States in the west to New Zealand in the far east. these

references encompass almost the entire product range of BHEL, covering turnkey power

projects of thermal, hydro and gas-based types, substation projects, rehabilitation

projects, besides a wide variety of products, like transformers, insulators, switchgears,

heat exchangers, castings and forgings, valves, well-head equipment, centrifugal

compressors, photo-voltaic equipment etc. apart from over 1110mw of boiler capacity

contributed in Malaysia, and execution of four prestigious power projects in Oman, some

of the other major successes achieved by the company have been in Australia, Saudi

Arabia, Libya, Greece, Cyprus, Malta, Egypt, Bangladesh, Azerbaijan, Sri Lanka, Iraq

etc.

The company has been successful in meeting demanding customer's requirements

in terms of complexity of the works as well as technological, quality and other

requirements viz. extended warrantees, associated O&M, financing packages etc. BHEL

has proved its capability to undertake projects on fast-track basis. The company has been

successful in meeting varying needs of the industry, be it captive power plants, utility

power generation or for the oil sector requirements. Executing of overseas projects has

also provided BHEL the experience of working with world renowned consulting

organizations and inspection agencies.

In addition to demonstrated capability to undertake turnkey projects on its own,

BHEL possesses the requisite flexibility to interface and complement with international

companies for large projects by supplying complementary equipment and meeting their

production needs for intermediate as well as finished products.

The success in the area of rehabilitation and life extension of power projects has

established BHEL as a comparable alternative to the original equipment manufacturers

(OEM’S) for such plants.

7

1.3. TECHNOLOGY UPGRADATION AND RESEARCH & DEVELOPMENT

To remain competitive and meet customers' expectations, BHEL lays great

emphasis on the continuous up gradation of products and related technologies, and

development of new products. The Company has upgraded its products to contemporary

levels through continuous in house efforts as well as through acquisition of new

technologies from leading engineering organizations of the world.

The Corporate R&D Division at Hyderabad, spread over a 140 acre complex,

leads BHEL's research efforts in a number of areas of importance to BHEL's product

range. Research and product development centers at each of the manufacturing divisions

play a complementary role.

BHEL's Investment in R&D is amongst the largest in the corporate sector in

India. Products developed in-house during the last five years contributed about 8.6% to

the revenues in 2000-2001.

BHEL has introduced, in the recent past, several state-of-the-art products

developed in-house: low-NOx oil / gas burners, circulating fluidized bed combustion

boilers, high-efficiency Pelton hydro turbines, petroleum depot automation systems, 36

kV gas-insulated sub-stations, etc. The Company has also transferred a few technologies

developed in-house to other Indian companies for commercialization.

Some of the on-going development & demonstration projects include: Smart wall

blowing system for cleaning boiler soot deposits, and micro-controller based governor for

diesel-electric locomotives. The company is also engaged in research in futuristic areas,

such as application of super conducting materials in power generations and industry, and

fuel cells for distributed, environment-friendly power generation.

1.3.1 HUMAN RESOURCE DEVELOPMENT INSTITUTE

The most prized asset of BHEL is its employees. The Human Resource

Development Institute and other HRD centers of the Company help in not only keeping

their skills updated and finely honed but also in adding new skills, whenever required.

Continuous training and retraining, positive, a positive work culture and participative

8

style of management, have engendered development of a committed and motivated work

force leading to enhanced productivity and higher levels of quality.

1.4. HEALTH, SAFETY AND ENVIRONMENT MANAGEMENT

BHEL, as an integral part of business performance and in its endeavor of

becoming a world-class organization and sharing the growing global concern on issues

related to Environment. Occupational Health and Safety, is committed to protecting

Environment in and around its own establishment, and to providing safe and healthy

working environment to all its employees. For fulfilling these obligations, Corporate

Policies have been formulated as:

1.4.1. ENVIRONMENTAL POLICY

Compliance with applicable Environmental Legislation/Regulation;

Continual Improvement in Environment Management Systems to protect our

natural environment and Control Pollution;

Promotion of activities for conservation of resources by Environmental

Management;

Enhancement of Environmental awareness amongst employees, customers and

suppliers. BHEL will also assist and co-operate with the concerned Government

Agencies and Regulatory Bodies engaged in environmental activities, offering the

Company's capabilities is this field.

1.4.2. OCCUPATIONAL HEALTH AND SAFETY POLICY

Compliance with applicable Legislation and Regulations;

Setting objectives and targets to eliminate/control/minimize risks due to

Occupational and Safety Hazards;

Appropriate structured training of employees on Occupational Health and Safety

(OH&S) aspects;

9

Formulation and maintenance of OH&S Management programs for continual

improvement;

Periodic review of OH&S Management System to ensure its continuing

suitability, adequacy and effectiveness;

Communication of OH&S Policy to all employees and interested parties.

The major units of BHEL have already acquired ISO 14001 Environmental

Management System Certification, and other units are in advanced stages of acquiring the

same. Action plan has been prepared to acquire OHSAS 18001 Occupational Health and

Safety Management System certification for all BHEL units.

In pursuit of these Policy requirements, BHEL will continuously strive to improve

work particles in the light of advances made in technology and new understandings in

Occupational Health, Safety and Environmental Science. Participation in the "Global

Compact" of the United Nations.

The "Global Compact" is a partnership between the United Nations, the business

community, international labor and NGOs. It provides a forum for them to work together

and improve corporate practices through co-operation rather than confrontation.

BHEL has joined the "Global Compact" of United Nations and has committed to

support it and the set of core values enshrined in its nine principles:

1.4.3. PRINCIPLES OF THE "GLOBAL COMPACT"

HUMAN RIGHTS

1. Business should support and respect the protection of internationally proclaimed

human rights; and

2. Make sure they are not complicit in human rights abuses.

10

LABOUR STANDARDS

3. Business should uphold the freedom of association and the effective recognition

of the right to collective bargaining;

4. The elimination of all form of forces and compulsory labor.

5. The effective abolition of child labor, and

6. Eliminate discrimination.

ENVIRONMENT

7. Businesses should support a precautionary approach to environmental challenges;

8. Undertake initiatives to promote greater environmental responsibility and

9. Encourage the development and diffusion of environmentally friendly

technologies.

By joining the "Global Compact", BHEL would get a unique opportunity of networking

with corporate and sharing experience relating to social responsibility on global basis.

11

1.5. BHEL UNITS

UNIT TYPE PRODUCT

1. Bhopal Heavy Electrical Plant Steam turbines , Turbo generators , Hydro

sets , Switch gear controllers

2. Haridwar

HEEP

CFFP

Heavy Electrical

Equipment Plant

Central Foundry Forge

Plant

Hydro turbines , Steam turbines, Gas

turbine, Turbo generators, Heavy castings

and forging. Control panels, Light aircrafts,

Electrical machines

3.Hyderabad

HPEP Heavy Power Equipment

Plant

Industrial turbo – sets, Compressors Pumps

and heaters, Bow mills, Heat exchangers oil

rings, Gas turbines , Switch gears, Power

generating set

4.Tiruchi

HPBP

SSTP

High Pressure Boiling

Plant

Steam less steel tubes, Spiral fin welded

tubes.

5.Jhansi

TP Transformer PlantTransformers, Diesel shunt less AC locos

and AC EMU

12

6.Banglore

EDN

EPD

Control Equipment

Division

Electro Porcelain Division

Energy meters, Water meters , Control

equipment, Capacitors , Photovoltaic panels,

Simulator , Telecommunication system,

Other advanced micro processor based

control system. Insulator and bushing,

Ceramic liners.

7.Ranipet

BAP Boiler Auxiliaries PlantElectrostatic precipitator, Air pre-heater,

Fans, Wind electric generators, Desalination

plants.

8.Goindwal Industrial Valves Plant Industrial valves and Fabrication

9.Jagdishpur

IP Insulator Plant. High tension ceramic, Insulation Plates and

bushings

10.Rudrapur Component Fabrication

Plant

Windmill, Solar water heating system

11.Gurgoan Amorphous Silicon Solar

Cell Plant.

Solar Photovoltaic Cells, Solar lanterns

chargers ,

Solar clocks

TABLE1

13

1.6. BHEL HARIDWAR

1.6.1. LOCATION

It is situated in the foot hills of Shivalik range in Haridwar. The main

administrative building is at a distance of about 8 km from Haridwar.

1.6.2. ADDRESS

Bharat Heavy Electrical Limited (BHEL)

Ranipur, Haridwar

PIN:- 249403

1.6.3. AREA

BHEL Haridwar consists of two manufacturing units, namely Heavy Electrical

Equipment Plant (HEEP) and Central Foundry Forge Plant (CFFP), having area

HEEP area:- 8.45 sq km

CFFP area:- 1.0 sq km

The Heavy Electricals Equipment Plant (HEEP) located in Haridwar, is one of the

major manufacturing plants of BHEL. The core business of HEEP includes design and

manufacture of large steam and gas turbines, turbo generators, hydro turbines and

generators, large AC/DC motors and so on.

Central Foundry Forge Plant (CFFP) is engaged in manufacture of Steel Castings:

Up to 50 Tons per Piece Wt & Steel Forgings: Up to 55 Tons per Piece Wt.

1.6.4. UNITS

There are two units in BHEL Haridwar as followed:

1) Heavy Electrical Equipment Plant (HEEP)

2) Central Foundry Forge Plant (CFFP).

14

THERE ARE 8 BLOCKS IN HEEP

BLOCKS WORK PERFORMED IN THE BLOCK

I. Electrical Machine Turbo generator, generator exciter , motor (ac and dc)

II. Fabrication Large size fabricated assemblies or components

III. Turbine & Auxiliary Steam ,hydro ,gas turbines, turbine blade , special tooling

IV. Feeder Winding of Turbo ,hydro generators ,insulation for ac & dc

motors

V. Fabrication Fabricated parts of steam turbine, water boxes, storage tank,

hydro turbine parts

VI. Fabrication

Stamping and die

manufacturing

Fabricated oil tanks, hollow guide blades, Rings, stator frames

and rotor spindle, all dies, stamping for generators and

motors

15

VII. Wood working Wooden packing, spacers.

VIII. Heaters & coolers LP heaters, ejectors, glands, steam and oil coolers,

Oil tank, bearing covers

TABLE 2

THERE ARE 3 SECTIONS IN CFFP

SECTIONS WORK PERFORMED IN THE SECTION

I. Foundry Casting of turbine rotor, casing and Francis runner

II. Forging Forging of small rotor parts

III. Machine shop Turning, boring, parting off, drilling etc.

TABLE 3

16

1.6.5. HEEP PRODUCT PROFILE

1. THERMAL SETS:

Steam turbines and generators up to 500 MW capacity for utility and combined

cycle applications

Capability to manufacture up to 1000 MW unit cycle.

2. GAS TURBINES:

Gas turbines for industry and utility application; range-3 to 200 MW (ISO).

Gas turbines based co-generation and combined cycle system .

3. HYDRO SETS:

Custom– built conventional hydro turbine of Kaplan, Francis and Pelton with

matching generators up to 250 MW unit size.

Pump turbines with matching motor-generators.

Mini / micro hydro sets.

Spherical butterfly and rotary valves and auxiliaries for hydro station.

4. EQUIPMENT FOR NUCLEAR POWER PLANTS:

Turbines and generators up to 500MW unit size.

Steam generator up to 500MW unit size.

Re-heaters / separators.

Heat exchangers and pressure vessels.

5. ELECTRICAL MACHINES:

DC general purpose and rolling mill machines from 100 to 19000KW suitable for

operation on voltage up to 1200V. These are provided with STDP, totally

enclosed and duct ventilated enclosures.

DC auxiliary mill motors.

17

6. CONTROL PANEL:

Control panel for voltage up to 400KW and control desks for generating stations

and EMV sub–stations.

7. CASTING AND FORGINGS:

Sophisticated heavy casting and forging of creep resistant alloy steels, stainless

steel and other grades of alloy meeting stringent international specifications.

8. DEFENCE:

Naval guns with collaboration of Italy.

18

2. STEAM TURBINE

2.1 INTRODUCTION

A turbine is a device that converts chemical energy into mechanical energy,

specifically when a rotor of multiple blades or vanes is driven by the movement of a fluid

or gas. In the case of a steam turbine, the pressure and flow of newly condensed steam

rapidly turns the rotor. This movement is possible because the water to steam conversion

results in a rapidly expanding gas. As the turbine’s rotor turns, the rotating shaft can work

to accomplish numerous applications, often electricity generation.

FIG.1 SECTIONAL VIEW OF A STEAM TURBINE

In a steam turbine, the steam’s energy is extracted through the turbine and the steam

leaves the turbine at a lower energy state. High pressure and temperature fluid at the inlet

of the turbine exit as lower pressure and temperature fluid. The difference is energy

converted by the turbine to mechanical rotational energy, less any aerodynamic and

mechanical inefficiencies incurred in the process. Since the fluid is at a lower pressure at

the exit of the turbine than at the inlet, it is common to say the fluid has been “expanded”

across the turbine. Because of the expanding flow, higher volumetric flow

19

occurs at the turbine exit (at least for compressible fluids) leading to the need for larger

turbine exit areas than at the inlet.

The generic symbol for a turbine used in a flow diagram is shown in Figure

below. The symbol diverges with a larger area at the exit than at the inlet. This is how

one can tell a turbine symbol from a compressor symbol. In Figure , the graphic is

colored to indicate the general trend of temperature drop through a turbine. In a turbine

with a high inlet pressure, the turbine blades convert this pressure energy into velocity or

kinetic energy, which causes the blades to rotate. Many green cycles use a turbine in this

fashion, although the inlet conditions may not be the same as for a conventional high

pressure and temperature steam turbine. Bottoming cycles, for instance, extract fluid

energy that is at a lower pressure and temperature than a turbine in a conventional power

plant. A bottoming cycle might be used to extract energy from the exhaust gases of a

large diesel engine, but the fluid in a bottoming cycle still has sufficient energy to be

extracted across a turbine, with the energy converted into rotational energy.

FIG.2 FLOW DIAGRAM OF A STEAM TURBINE

Turbines also extract energy in fluid flow where the pressure is not high but

where the fluid has sufficient fluid kinetic energy. The classic example is a wind turbine,

which converts the wind’s kinetic energy to rotational energy. This type of kinetic energy

conversion is common in green energy cycles for applications ranging from larger wind

turbines to smaller hydrokinetic turbines currently being designed for and demonstrated

in river and tidal applications. Turbines can be designed to work well in a variety of

fluids, including gases and liquids, where they are used not only to drive generators, but

also to drive compressors or pumps.

20

One common (and somewhat misleading) use of the word “turbine” is “gas

turbine,” as in a gas turbine engine. A gas turbine engine is more than just a turbine and

typically includes a compressor, combustor and turbine combined to be a self-contained

unit used to provide shaft or thrust power. The turbine component inside the gas turbine

still provides power, but a compressor and combustor are required to make a self-

contained system that needs only the fuel to burn in the combustor.

An additional use for turbines in industrial applications that may also be

applicable in some green energy systems is to cool a fluid. As previously mentioned,

when a turbine extracts energy from a fluid, the fluid temperature is reduced. Some

industries, such as the gas processing industry, use turbines as sources of refrigeration,

dropping the temperature of the gas going through the turbine. In other words, the

primary purpose of the turbine is to reduce the temperature of the working fluid as

opposed to providing power. Generally speaking, the higher the pressure ratio across a

turbine, the greater the expansion and the greater the temperature drop. Even where

turbines are used to cool fluids, the turbines still produce power and must be connected

to a power absorbing device that is part of an overall system.

Also note that turbines in high inlet-pressure applications are sometimes called

expanders. The terms “turbine” and “expander” can be used interchangeably for most

applications, but expander is not used when referring to kinetic energy applications, as

the fluid does not go through significant expansion.

2.2. ADVANTAGES:-

Ability to utilize high pressure and high temperature steam.

High efficiency.

High rotational speed.

High capacity/weight ratio.

Smooth, nearly vibration-free operation.

No internal lubrication.

Oil free exhausts steam.

21

2.3 DISADVANTAGES:-

For slow speed application reduction gears are required. The steam turbine cannot

be made reversible. The efficiency of small simple steam turbines is poor.

2.4 STEAM TURBINES THE MAINSTAY OF BHEL

BHEL has the capability to design, manufacture and commission steam turbines

of up to 1000 MW rating for steam parameters ranging from 30 bars to 300 bars

pressure and initial & reheat temperatures up to 600 ºC.

Turbines are built on the building block system, consisting of modules suitable

for a range of output and steam parameters.

For a desired output and steam parameters appropriate turbine blocks can be

selected.

22

3. TYPES OF STEAM TURBINE

There are complicated methods to properly harness steam power that give rise tothe two primary turbine designs: impulse and reaction turbines. These different designsengage the steam in a different method so as to turn the rotor

3.1 IMPULSE TURBINE

The principle of the impulse steam turbine consists of a casing containing

stationary steam nozzles and a rotor with moving or rotating buckets.

The steam passes through the stationary nozzles and is directed at high velocity against

rotor buckets causing the rotor to rotate at high speed.

The following events take place in the nozzles:

1. The steam pressure decreases.

2. The enthalpy of the steam decreases.

3. The steam velocity increases.

4. The volume of the steam increases.

5. There is a conversion of heat energy to kinetic energy as the heat energy from the

decrease in steam enthalpy is converted into kinetic energy by the increased

steam velocity.

3.2 THE IMPULSE PRINCIPLE

If steam at high pressure is allowed to expand through stationary nozzles, the

result will be a drop in the steam pressure and an increase in steam velocity. In fact, the

steam will issue from the nozzle in the form of a high-speed jet. If this high steam is

applied to a properly shaped turbine blade, it will change in direction due to the shape of

the blade. The effect of this change in direction of the steam flow will be to produce an

impulse force, on the blade causing it to move. If the blade is attached to the rotor of a

turbine, then the rotor will revolve. Force applied to the blade is developed by causing the

steam to change direction of flow (Newton’s 2nd Law – change of momentum). The

change of momentum produces the impulse force. The fact that the pressure does not

drop across the moving blades is the distinguishing feature of the impulse turbine. The

23

pressure at the inlet to the moving blades is the same as the pressure at the outlet from

the moving blades.

3.3 REACTION PRINCIPLE

A reaction turbine has rows of fixed blades alternating with rows of moving

blades. The steam expands first in the stationary or fixed blades where it gains some

velocity as it drops in pressure. It then enters the moving blades where its direction of

flow is changed thus producing an impulse force on the moving blades. In addition,

however, the steam upon passing through the moving blades again expands and further

drops in pressure giving a reaction force to the blades. This sequence is repeated as the

steam passes through additional rows of fixed and moving blades.

3.4 IMPULSE TURBINE STAGING

In order for the steam to give up all its kinetic energy to the moving blades in an

impulse turbine, it should leave the blades at zero absolute velocity. This condition will

exist if the blade velocity is equal to one half of the steam velocity. Therefore, for good

efficiency the blade velocity should be about one half of steam velocity.

In order to reduce steam velocity and blade velocity, the following methods may be used:

1. Pressure compounding.

2. Velocity compounding.

3. Pressure-velocity compounding.

4. Pressure Compounding

24

4. TURBINE PARTS

4.1 TURBINE BLADES

Cylindrical reaction blades for HP, IP and LP Turbines

3-DS blades, in initial stages of HP and IP Turbine, to reduce secondary losses.

Twisted blade with integral shroud, in last stages of HP, IP and initial stages of

LP turbines, to reduce profile and Tip leakage losses

o Free standing LP moving blades Tip sections with supersonic

design

o Fir-tree root

o Flame hardening of the leading edge

Banana type hollow guide blade

o Tapered and forward leaning for optimized mass flow distribution

o Suction slits for moisture removal

4.2 TURBINE CASING

Casings or cylinders are of the horizontal split type. This is not ideal, as the heavy

flanges of the joints are slow to follow the temperature changes of the cylinder walls.

However, for assembling and inspection purposes there is no other solution. The casing is

heavy in order to withstand the high pressures and temperatures. It is general practice to

let the thickness of walls and flanges decrease from inlet- to exhaust-end.

The casing joints are made steam tight, without the use of gaskets, by matching

the flange faces very exactly and very smoothly. The bolt holes in the flanges are drilled

for smoothly fitting bolts, but dowel pins are often added to secure exact alignment of the

flange joint. Double casings are used for very high steam pressures. The high pressure is

applied to the inner casing, which is open at the exhaust end, letting the turbine exhaust to

the outer casings.

25

4.3 TURBINE ROTORS

The design of a turbine rotor depends on the operating principle of the turbine. The

impulse turbine with pressure drop across the stationary blades must have seals between

stationary blades and the rotor. The smaller the sealing area, the smaller the leakage;

therefore the stationary blades are mounted in diaphragms with labyrinth seals around the

shaft. This construction requires a disc rotor. Basically there are two types of rotor:

DISC ROTORS

All larger disc rotors are now machined out of a solid forging of nickel steel;

this should give the strongest rotor and a fully balanced rotor. It is rather

expensive, as the weight of the final rotor is approximately 50% of the initial

forging. Older or smaller disc rotors have shaft and discs made in separate

pieces with the discs shrunk on the shaft. The bore of the discs is made 0.1%

smaller in diameter than the shaft. The discs are then heated until they easily

are slid along the shaft and located in the correct position on the shaft and

shaft key. A small clearance between the discs prevents thermal stress in the

shaft.

DRUM ROTORS

The first reaction turbines had solid forged drum rotors. They were strong,

generally well balanced as they were machined over the total surface. With the

increasing size of turbines the solid rotors got too heavy pieces. For good

balance the drum must be machined both outside and inside and the drum

must be open at one end. The second part of the rotor is the drum end cover

with shaft.

26

5. CONSTRUCTIONAL FEATURES OF A BLADE

The blade can be divided into 3 parts:

The profile, which converts the thermal energy of steam into kinetic energy, with

a certain efficiency depending upon the profile shape.

The root, which fixes the blade to the turbine rotor, giving a proper anchor to the

blade, and transmitting the kinetic energy of the blade to the rotor.

The damping element, which reduces the vibrations which necessarily occur in

the blades due to the steam flowing through the blades. These damping elements

may be integral with blades, or they may be separate elements mounted between

the blades.

Each of these elements will be separately dealt with in the following sections.

5.1 H.P. BLADE PROFILES

In order to understand the further explanation, a familiarity of the terminology used is

required. The following terminology is used in the subsequent sections.

CAMBER LINE

C H O R D

BITANGENT LINE

FIG.3 HIGH PRESSURE BLADE PROFILE

27

If circles are drawn tangential to the suction side and pressure side profiles of a

blade, and their centers are joined by a curve, this curve is called the camber line. This

camber line intersects the profile at two points A and B. The line joining these points is

called chord, and the length of this line is called the chord length. A line which is

tangential to the inlet and outlet edges is called the bitangent line. The angle which this

line makes with the circumferential direction is called the setting angle. Pitch of a blade is

the circumferential distance between any point on the profile and an identical point on the

next blade.

5.2 CLASSIFICATION OF PROFILES

There are two basic types of profiles - Impulse and Reaction. In the impulse type

of profiles, the entire heat drop of the stage occurs only in the stationary blades. In the

reaction type of blades, the heat drop of the stage is distributed almost equally between

the guide and moving blades.

Though the theoretical impulse blades have zero pressure drop in the moving

blades, practically, for the flow to take place across the moving blades, there must be a

small pressure drop across the moving blades also. Therefore, the impulse stages in

practice have a small degree of reaction. These stages are therefore more accurately,

though less widely, described as low-reaction stages.

The presently used reaction profiles are more efficient than the impulse profiles at

part loads. This is because of the more rounded inlet edge for reaction profiles. Due to

this, even if the inlet angle of the steam is not tangential to the pressure-side profile of the

blade, the losses are low.

However, the impulse profiles have one advantage. The impulse profiles can take

a large heat drop across a single stage, and the same heat drop would require a greater

number of stages if reaction profiles are used, thereby increasing the turbine length.

28

The Steam turbines use the impulse profiles for the control stage (1st stage), and

the reaction profiles for subsequent stages. There are three reasons for using impulse

profile for the first stage.

a) Most of the turbines are partial arc admission turbines. If the first stage is a

reaction stage, the lower half of the moving blades do not have any inlet

steam, and would ventilate. Therefore, most of the stage heat drop should

occur in the guide blades.

b) The heat drop across the first stage should be high, so that the wheel chamber

of the outer casing is not exposed to the high inlet parameters. In case of -4

turbines, the inner casing parting plane strength becomes the limitation, and

therefore requires a large heat drop across the 1st stage.

c) Nozzle control gives better efficiency at part loads than throttle control.

d) The number of stages in the turbine should not be too high, as this will

increase the length of the turbine.

There are exceptions to the rule. Turbines used for CCPs, and BFP drive turbines

do not have a control stage. They are throttle-governed machines. Such designs are used

when the inlet pressure slides. Such machines only have reaction stages. However, the

inlet passages of such turbines must be so designed that the inlet steam to the first

reaction stage is properly mixed, and occupies the entire 360 degrees. There are also

cases of controlled extraction turbines where the L.P. control stage is an impulse stage.

This is either to reduce the number of stages to make the turbine short, or to increase the

part load efficiency by using nozzle control, which minimizes throttle losses.

5.3 H.P. BLADE ROOTS

The root is a part of the blade that fixes the blade to the rotor or stator. Its design

depends upon the centrifugal and steam bending forces of the blade. It should be

designed such that the material in the blade root as well as the rotor / stator claw and any

fixing element are in the safe limits to avoid failure. The roots are T-root and Fork-root.

The fork root has a higher load-carrying capacity than the T-root. It was found that

29

machining this T-root with side grip is more of a problem. It has to be machined by

broaching, and the broaching machine available could not handle the sizes of the root.

The typical roots used for the HP moving blades for various steam turbine applications

are shown in the following figure:

T-ROOT

T-ROOT WITH SIDE GRIP

FORK ROOT

TABLE 4 BLADE ROOTS

30

5.4 L.P. BLADE PROFILES

The LP blade profiles of moving blades are twisted and tapered. These blades are

used when blade height-to-mean stage diameter ratio (h/Dm) exceeds 0.2.

5.5 LP BLADE ROOTS

The roots of LP blades are as follows:

1) 2 blading :

The roots of both the LP stages in –2 type of LP blading are T-roots.

2) 3 blading:

The last stage LP blade of HK, SK and LK blades have a fork-root. SK blades have

4-fork roots for all sizes. HK blades have 4-fork roots up to 56 size, where modified

profiles are used. Beyond this size, HK blades have 3 fork roots. LK blades have 3-fork

roots for all sizes. The roots of the LP blades of preceding stages are of T-roots.

5.6 DYNAMICS IN BLADE

The excitation of any blade comes from different sources. They are:

a) Nozzle-passing excitation: As the blades pass the nozzles of the stage, they

encounter flow disturbances due to the pressure variations across the guide blade

passage. They also encounter disturbances due to the wakes and eddies in the flow

path. These are sufficient to cause excitation in the moving blades. The excitation

gets repeated at every pitch of the blade. This is called nozzle-passing frequency

excitation. The order of this frequency = no. of guide blades x speed of the

machine. Multiples of this frequency are considered for checking for resonance.

b) Excitation due to non-uniformities in guide-blades around the periphery. These

can occur due to manufacturing inaccuracies, like pitch errors, setting angle

variations, inlet and outlet edge variations, etc.

31

For HP blades, due to the thick and cylindrical cross-sections and short blade heights, the

natural frequencies are very high. Nozzle-passing frequencies are therefore necessarily

considered, since resonance with the lower natural frequencies occurs only with these

orders of excitation.

In LP blades, since the blades are thin and long, the natural frequencies are low.

The excitation frequencies to be considered are therefore the first few multiples of speed,

since the nozzle-passing frequencies only give resonance with very high modes, where

the vibration stresses are low.

The HP moving blades experience relatively low vibration amplitudes due to their

thicker sections and shorter heights. They also have integral shrouds. These shrouds of

adjacent blades butt against each other forming a continuous ring. This ring serves two

purposes – it acts as a steam seal, and it acts as a damper for the vibrations. When

vibrations occur, the vibration energy is dissipated as friction between shrouds of

adjacent blades.

For HP guide blades of Wesel design, the shroud is not integral, but a shroud band

is riveted to a number of guide blades together. The function of this shroud band is

mainly to seat the steam. In some designs HP guide blades may have integral shrouds like

moving blades. The primary function remains steam sealing.

In industrial turbines, in LP blades, the resonant vibrations have high amplitudes

due to the thin sections of the blades, and the large lengths. It may also not always be

possible to avoid resonance at all operating conditions. This is because of two reasons.

Firstly, the LP blades are standardized for certain ranges of speeds, and turbines may be

selected to operate anywhere in the speed range. The entire design range of operating

speed of the LP blades cannot be outside the resonance range. It is, of course, possible to

design a new LP blade for each application, but this involves a lot of design efforts and

manufacturing cycle time. However, with the present-day computer packages and

manufacturing methods, it has become feasible to do so. Secondly, the driven machine

may be a variable speed machine like a compressor or a boiler-feed-pump. In this case

32

also, it is not possible to avoid resonance. In such cases, where it is not possible to avoid

resonance, a damping element is to be used in the LP blades to reduce the dynamic

stresses, so that the blades can operate continuously under resonance also. There may be

blades which are not adequately damped due to manufacturing inaccuracies. The need for

a damping element is therefore eliminated. In case the frequencies of the blades tend

towards resonance due to manufacturing inaccuracies, tuning is to be done on the blades

to correct the frequency. This tuning is done by grinding off material at the tip (which

reduces the inertia more than the stiffness) to increase the frequency, and by grinding off

material at the base of the profile (which reduces the stiffness more than the inertia) to

reduce the natural frequency.

The damping in any blade can be of any of the following types:

a) Material damping: This type of damping is because of the inherent damping

properties of the material which makes up the component.

b) Aerodynamic damping: This is due to the damping of the fluid which

surrounds the component in operation.

c) Friction damping: This is due to the rubbing friction between the component

under consideration with any other object.

Out of these damping mechanisms, the material and aerodynamic types of

damping are very small in magnitude. Friction damping is enormous as compared to the

other two types of damping. Because of this reason, the damping elements in blades

generally incorporate a feature by which the vibrational energy is dissipated as frictional

heat. The frictional damping has a particular characteristic. When the frictional force

between the rubbing surfaces is very small as compared to the excitation force, the

surfaces slip, resulting in friction damping. However, when the excitation force is small

when compared to the frictional force, the surfaces do not slip, resulting in locking of the

surfaces.

This condition gives zero friction damping, and only the material and

aerodynamic damping exists. In a periodically varying excitation force, it may frequently

happen that the force is less than the friction force. During this phase, the damping is very

33

less. At the same time, due to the locking of the rubbing surfaces, the overall stiffness

increases and the natural frequency shifts drastically away from the individual value. The

response therefore also changes in the locked condition. The resonant response of a

system therefore depends upon the amount of damping in the system (which is

determined by the relative duration of slip and stick in the system, i.e., the relative

magnitude of excitation and friction forces) and the natural frequency of the system

(which alters between the individual values and the locked condition value, depending

upon the slip or stick condition).

5.7 BLADING MATERIALS

Among the different materials typically used for blading are 403 stainless steel,

422 stainless steel, A-286, and Haynes Stellite Alloy Number 31 and titanium alloy. The

403 stainless steel is essentially the industry’s standard blade material and, on impulse

steam turbines, it is probably found on over 90 percent of all the stages. It is used because

of its high yield strength, endurance limit, ductility, toughness, erosion and corrosion

resistance, and damping. It is used within a Brinell hardness range of 207 to 248 to

maximize its damping and corrosion resistance. The 422 stainless steel material is applied

only on high temperature stages (between 700 and 900°F or 371 and 482°C), where its

higher yield, endurance, creep and rupture strengths are needed.

The A-286 material is a nickel-based super alloy that is generally used in hot gas

expanders with stage temperatures between 900 and 1150°F (482 and 621°C). The

Haynes Stellite Alloy Number 31 is a cobalt-based super alloy and is used on jet

expanders when precision cast blades are needed. The Haynes Stellite Number 31 is used

at stage temperatures between 900 and 1200°F (482 and 649°C). Another blade material

is titanium. Its high strength, low density, and good erosion resistance make it a good

candidate for high speed or long-last stage blading.

34

6. MANUFACTURING PROCESS

6.1 INTRODUCTION

Manufacturing process is that part of the production process which is directly

concerned with the change of form or dimensions of the part being produced. It does not

include the transportation, handling or storage of parts, as they are not directly concerned

with the changes into the form or dimensions of the part produced.

Manufacturing is the backbone of any industrialized nation. Manufacturing and

technical staff in industry must know the various manufacturing processes, materials

being processed, tools and equipments for manufacturing different components or

products with optimal process plan using proper precautions and specified safety rules to

avoid accidents. Beside above, all kinds of the future engineers must know the basic

requirements of workshop activities in term of man, machine, material, methods, money

and other infrastructure facilities needed to be positioned properly for optimal shop

layouts or plant layout and other support services effectively adjusted or located in the

industry or plant within a well planned manufacturing organization.

Today’s competitive manufacturing era of high industrial development and

research, is being called the age of mechanization, automation and computer integrated

manufacturing. Due to new researches in the manufacturing field, the advancement has

come to this extent that every different aspect of this technology has become a full-

fledged fundamental and advanced study in itself. This has led to introduction of

optimized design and manufacturing of new products. New developments in

manufacturing areas are deciding to transfer more skill to the machines for considerably

reduction of manual labor.

6.2 CLASSIFICATION OF MANUFACTURING PROCESSES

For producing of products materials are needed. It is therefore important to know

the characteristics of the available engineering materials. Raw materials used

manufacturing of products, tools, machines and equipments in factories or industries are

for providing commercial castings, called ingots. Such ingots are then processed in

35

rolling mills to obtain market form of material supply in form of bloom, billets, slabs and

rods.

These forms of material supply are further subjected to various manufacturing processes

for getting usable metal products of different shapes and sizes in various manufacturing

shops. All these processes used in manufacturing concern for changing the ingots into

usable products may be classified into six major groups as

Primary shaping processes

Secondary machining processes

Metal forming processes

Joining processes

Surface finishing processes and

Processes effecting change in properties

6.2.1 PRIMARY SHAPING PROCESSES

Primary shaping processes are manufacturing of a product from an amorphous

material. Some processes produces finish products or articles into its usual form whereas

others do not, and require further working to finish component to the desired shape and

size. The parts produced through these processes may or may not require to undergo

further operations. Some of the important primary shaping processes are:

(1) Casting

(2) Powder metallurgy

(3) Plastic technology

(4) Gas cutting

(5) Bending and

(6) Forging.

36

6.2.2 SECONDARY OR MACHINING PROCESSES

As large number of components require further processing after the primary

processes. These components are subjected to one or more number of machining

operations in machine shops, to obtain the desired shape and dimensional accuracy on flat

and cylindrical jobs. Thus, the jobs undergoing these operations are the roughly finished

products received through primary shaping processes. The process of removing the

undesired or unwanted material from the work-piece or job or component to produce a

required shape using a cutting tool is known as machining. This can be done by a manual

process or by using a machine called machine tool (traditional machines namely lathe,

milling machine, drilling, shaper, planner, slotter). In many cases these operations are

performed on rods, bars and flat surfaces in machine shops.

These secondary processes are mainly required for achieving dimensional

accuracy and a very high degree of surface finish. The secondary processes require the

use of one or more machine tools, various single or multi-point cutting tools (cutters), job

holding devices, marking and measuring instruments, testing devices and gauges etc. for

getting desired dimensional control and required degree of surface finish on the work-

pieces. The example of parts produced by machining processes includes hand tools

machine tools instruments, automobile parts, nuts, bolts and gears etc. Lot of material is

wasted as scrap in the secondary or machining process. Some of the common secondary

or machining processes are:

Turning

Threading

Knurling

Milling

Drilling

Boring

Planning

Shaping

Slotting

Sawing

37

Broaching

Hobbing

Grinding

Gear Cutting

Thread cutting and

Unconventional machining processes namely machining with Numerical

control (NC) machines tools or Computer Numerical Control(CNC)

machine tool using ECM, LBM, AJM, USM setups.

38

7. BLOCK 3 LAY-OUT

TABLE5 LAYOUT OF BLOCK-3

39

8. CLASSIFICATION OF BLOCK 3BAY-1 IS FURTHER DIVIDED INTO THREE PARTS

1. HMS -

In this shop heavy machine work is done with the help of different NC &

CNC machines such as center lathes, vertical and horizontal boring &

milling machines. Asia’s largest vertical boring machine is installed here

and CNC horizontal boring milling machines from Skoda of

Czechoslovakia.

2. Assembly Section (of hydro turbines) –

In this section assembly of hydro turbines are done. Blades of turbine are

1st assemble on the rotor & after it this rotor is transported to balancing

tunnel where the balancing is done. After balancing the rotor, rotor &

casings both internal & external are transported to the customer. Total

assembly of turbine is done in the company which purchased it by

B.H.E.L.

3. OSBT (over speed balancing tunnel)-

In this section, rotors of all type of turbines like LP(low pressure),

HP(high pressure)& IP(Intermediate pressure) rotors of Steam turbine ,

rotors of Gas & Hydro turbine are balanced .In a large tunnel, Vacuum of

2 torr is created with the help of pumps & after that rotor is placed on

pedestal and rotted with speed of 2500-4500 rpm. After it in a computer

control room the axis of rotation of rotor is seen with help of computer &

then balance the rotor by inserting the small balancing weight in the

grooves cut on rotor.

40

FIG.4 OVERSPEED AND VACCUM BALANCING TUNNEL

For balancing and over speed testing of rotors up to 320 tons in weight,

1800 mm in length and 6900 mm diameter under vacuum conditions of 1

Torr

BAY –2 IS DIVIDED IN TO 2 PARTS:

1. HMS– In this shop several components of steam turbine like LP, HP & IP

rotors, Internal & external casing are manufactured with the help of different

operations carried out through different NC & CNC machines like grinding,

drilling, vertical & horizontal milling and boring machines, center lathes,

planer, Kopp milling machine.

2 .Assembly section– In this section assembly of steam turbines up to 1000 MW

Is assembled. 1st moving blades are inserted in the grooves cut on

circumferences of rotor, then rotor is balanced in balancing tunnel in bay-1.

After is done in which guide blades are assembled inside the internal casing &

41

then rotor is fitted inside this casing. After it this internal casing with rotor is

inserted into the external.

BAY 3 IS DIVIDED INTO 3 PARTS:

1. Bearing section – In this section Journal bearings are manufactured which are

used in turbines to overcome the vibration & rolling friction by providing the

proper lubrication.

2. Turning section – In this section small lathe machines, milling & boring

machines, grinding machines & drilling machines are installed. In this section

small jobs are manufactured like rings, studs, disks etc.

3. Governing section – In this section governors are manufactured. These

governors are used in turbines for controlling the speed of rotor within the

certain limits. 1st all components of governor are made by different operations

then these all parts are treated in heat treatment shop for providing the

hardness. Then these all components are assembled into casing. There are more

than 1000 components of Governor.

BAY-4 IS DIVIDED INTO 3 PARTS:

1. TBM (turbine blade manufacturing) shop- In this shop solid blade of both

steam & gas turbine are manufactured. Several CNC & NC machines are

installed here such as Copying machine, Grinding machine, Rhomboid milling

machine, Duplex milling machine, T- root machine center, Horizontal tooling

center, Vertical & horizontal boring machine etc.

42

FIG.5 STEAM TURBINE CASING AND ROTORS IN ASSEMBLY AREA

2. Turning section- Same as the turning section in Bay-3, there are several small

Machine like lathes machines, milling, boring, grinding machines etc.

FIG.6 CNC ROTOR TURNING LATHE

Heat treatment shop-

In this section there are several tests performed for checking the hardness of

different components. Tests performed are Sterelliting, Nitriding, DP test.

43

9. BLADE SHOP

Blade shop is an important shop of Block 3. Blades of all the stages of turbine are

made in this shop only. They have a variety of centre lathe and CNC machines to perform

the complete operation of blades. The designs of the blades are sent to the shop and the

Respective job is distributed to the operators. Operators perform their job in a fixed

interval of time.

9.1 TYPES OF BLADES

Basically the design of blades is classified according to the stages of turbine. The

size of LP TURBINE BLADES is generally greater than that of HP TURBINE BLADES.

At the first T1, T2, T3 & T4 kinds of blades were used, these were 2nd generation blades.

Then it was replaced by TX, BDS (for HP TURBINE) & F shaped blades. The most

modern blades are F & Z shaped blades.

FIG.7 TYPES OF BLADES

44

9.2 OPERATIONS PERFORMED ON BLADES

Some of the important operations performed on blade manufacturing are:-

Milling

Blank Cutting

Grinding of both the surfaces

Cutting

Root milling

9.3 MACHINING OF BLADES

Machining of blades is done with the help of Lathe & CNC machines. Some of the

machines are:-

Centre lathe machine

Vertical Boring machine

Vertical Milling machine

CNC lathe machine

FIG.8 SCHEMATIC DIAGRAM OF A CNC MACHINE

45

9.4 NEW BLADE SHOP

A new blade shop is being in operation, mostly 500mw turbine blades are

manufactured in this shop. This is a highly hi tech shop where complete manufacturing of

blades is done using single advanced CNC machines. Complete blades are finished using

modernized CNC machines. Some of the machines are:-

Pama CNC ram boring machine

Wotum horizontal machine with 6 axis CNC control

CNC shaping machine

FIG.9 CNC SHAPING MACHINE

46

10. CONCLUSION

Gone through rigorous one month training under the guidance of capable engineers

and workers of BHEL Haridwar in Block-3 “TURBINE MANUFACTURING” headed by

Senior Engineer of department Mr. A.K. KHUSHWAHA situated in Ranipur, Haridwar,

Uttarakhand.

The training was specified under the Turbine Manufacturing Department. Working

under the department I came to know about the basic grinding, scaling and machining

processes which was shown on heavy to medium machines. Duty lathes were planted in the

same line where the specified work was undertaken.

The training brought to my knowledge the various machining and fabrication

processes went not only in the manufacturing of blades but other parts of the turbine.