136045679 BHEL Haridwar Block 3 Turbine Manufacturing Training Report (1)

A Training report On “TURBINE MANUFACTURING” At BHEL HARIDWAR Submitted in partial fulfillment of requirements for the degree of Bachelor of Technology In Mechanical Engineering Submitted By: ABHINAV BARTHWAL B.Tech. (Final Year) Submitted To: MOHD.YUNUS SHEIKH Sr. Lecturer Department of Mechanical Engineering GOVT. ENGINEERING COLLEGE, BIKANER RAJASTHA N TECHNICAL UNIVERSITY, KOTA 2012-13

ACKNOWLEDGEMENT “Inspiration and motivation have always played a key role in the success of any ve nture.” Success in such comprehensive report can’t be achieved single handed. It is the team effort that sail the ship to the coast. So I would like to express my s incere thanks to my mentor MR. A.K. KHUSHWAHA Sir. I am also grateful to the man agement 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 pleasur e to express my gratitude to the department of Mechanical Engineering for their prudent response in course of completing my training report. I am highly indebte d 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 dir ection, advice, discussion and constant encouragement given by them has been so help full in completing the work successfully [i]

INDEX S.R. NO. TOPIC INTRODUCTION PAGE NO. 1 1. BHEL 1.1.OVERVIEW 1.2.WORKING AREAS 1.2.1 POWER GENERATION 1.2.2 POWER TRANSMISS ION &DISTRIBUTION 1.2.3 INDUSTRIES 1.2.4 TRANSPORTATION 1.2.5 TELECOMMUNICATION 1.2.6 RENEWABLE ENERGY 1.2.7 INTERNATIONAL OPERATIONS 1.3 TECHNOLOGY UP GRADATIO N AND RESEARCH AND DEVELOPMENT 1.3.1HUMAN RESOURCE DEVELOPMENT INSTITUTE 1.4 HEA LTH, SAFETY AND ENVIRONMENT MANAGEMENT 1.4.1 ENVIRONMENTAL POLICY 1.4.2 OCCUPATI ONAL HEALTH AND SAFETY POLICY 1.4.3 PRINCIPLES OF THE "GLOBAL COMPACT" 1.5 BHEL UNITS 1.6 BHEL HARIDWAR 1.6.1LOCATION 1.6.2ADDRESS 1.6.3 AREA 1.6.4 UNITS 1.6.5 HEEP PRODUCT PROFILE 2 – 17 2 3 3 3 4 5 5 5 6 7 7 8 8 8 9 11 13 13 13 13 14 16 [ii]

2. STEAM TURBINE 2.1 INTRODUCTION 2.2 ADVANTAGES 2.3DISADVANTAGES 2.4 STEAM TURBINE S THE MAINSTAY OF BHEL 18-21 18 20 21 21 3. TYPES OF STEAM TURBINE 3.1 IMPULSE TURBINE 3.2 THE IMPULSE TURBINE PRINCIPLE 3.3 REACTION PRINCIPLE 3.4 IMPULSE TURBINE STAGING 22-23 22 22 23 23 4. TURBINE PARTS 4.1 TURBINE BLADES 4.2 TURBINE CASING 4.3 TURBINE ROTORS 24-25 24 24 25 5. CONSTRUCTIONAL FEATURES OF A BLADE 5.1 H.P. BLADE PROFILE 5.2 CLASSIFICATION OF PROFILES 5.3 H.P BLADE ROOTS 5.4 L.P BLADE PROFILE 5.5 L.P BLADE ROOTS 5.6 DYNAM ICS IN BLADE 5.7 BLADING MATERIALS 26-33 26 27 28 30 30 30 33 6. MANUFACTURING PROCESS 6.1 INTRODUCTION 6.2 CLASSIFICATION OF MANUFACTURING PROCE SS 6.2.1 PRIMARY SHAPING PROCESSES [iii] 34-37 34 34 35

6.2.2 SECONDAY OR MACHINING PROCESSES 36 7. BLOCK-3 LAY-OUT 38 8. CLASSIFICATION OF BLOCK-3 39-42 9. BLADE SHOP 9.1 TYPES OF BLADES 9.2 OPERATIONS PERFORMED ON BLADES 9.3 MACHINING OF BLADES 9.4 NEW BLADE SHOP 43-45 43 44 44 45 10. CONCLUSION 46 [iv]

FIGURE INDEX S.R.NO. 1. 2. 3. 4. 5. TOPIC SECTIONAL VIEW OF A STEAM TURBINE FLOW DIAGRAM OF A STEAM TURBINE HIGH PRE SSURE BLADE PROFILE OVERSPEED AND VACCUM BALANCING TUNNEL STEAM TURBINE CASING A ND ROTORS IN ASSEMBLING AREA PAGE NO. 18 19 26 40 42 6. 7. 8. 9. CNC ROTOR TURNING LATHE TYPES OF BLADES SCHEMATIC DIAGRAM OF A CNC MACHINE CNC S HAPING MACHINE 42 43 44 45 [v]

TABLE INDEX S.R.NO. 1. 2. 3. 4. 5. BHEL UNITS BLOCKS IN HEEP SECTIONS IN CFFP BLADE ROOTS LA YOUT OF BLOCK-3 TOPIC PAGE NO. 12 14 15 29 38 [vi]

INTRODUCTION BHEL is the largest engineering and manufacturing enterprise in India in the ene rgy 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 E lectrical 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 c ontinuously since 1971-72. BHEL caters to core sectors of the Indian Economy viz ., Power Generation s & Transmission, Industry, Transportation, Telecommunicatio n, Renewable Energy, Defense, etc. The wide network of BHEL s 14 manufacturing d ivision, four power Sector regional centers, over 150 project sites, eight servi ce centers and 18 regional offices, enables the Company to promptly serve its cu stomers and provide them with suitable products, systems and services – efficientl y and at competitive prices. BHEL has already attained ISO 9000 certification fo r quality management, and ISO 14001 certification for environment management. Th e company’s inherent potential coupled with its strong performance make this one o f the “NAVRATNAS”, which is supported by the government in their endeavor to become future global players. 1

1. BHEL 1.1. OVERVIEW Bharat Heavy Electricals Limited (B.H.E.L.) is the largest enginee ring and manufacturing enterprise in India. BHEL caters to core sectors of the I ndian Economy viz., Power Generation s & Transmission, Industry, Transportation, Telecommunication, Renewable Energy, Defense and many more. Established in 1960 s under the Indo-Soviet Agreements of 1959 and 1960 in the area of Scientific, T echnical and Industrial Cooperation. BHEL has its setup spread all over India na mely New Delhi, Gurgaon, Haridwar, Rudrapur, Jhansi, Bhopal, Hyderabad, Jagdishp ur , Tiruchirapalli, Bangalore and many more. Over 65% of power generated in Ind ia 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 corpo rate sector in India. Net Profit of the company in the year 2011-2012 was record ed as 6868 crore having a high of 21.2% in comparison to last year. BHEL has alr eady attained ISO 9000 certification for quality management, and ISO 14001 certi fication for environment management. It is one of India s nine largest Public Se ctor Undertakings or PSUs, known as the NAVRATNAS or the nine jewels The power plant equipment manufactured by BHEL is based on contemporary technology compar able to the best in the world The wide network of BHEL s 14 manufacturing divisi ons, four Power Sector regional centre, over 100 project sites, eight service ce ntre and 18 regional offices, enables the Company to promptly serve its customer s and provide them with suitable products, systems and services – efficiently 2

1.2. WORKING AREAS 1.2.1. POWER GENERATION Power generation sector comprises the rmal, gas, hydro and nuclear power plant business as of 31.03.2001, BHEL supplie d 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 capa bilities for executing power projects from concept to commissioning, it possesse s the technology and capability to produce thermal sets with super critical para meters 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 ach ieve higher plant efficiencies. to make efficient use of the high-ash-content co al available in India, BHEL supplies circulating fluidized bed combustion boiler s 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 ty pes for different head discharge combination are also engineering and manufactur ed 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 equipme nt manufactured by BHEL is based on contemporary technology comparable to the be st 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 transformer s, instrument transformers, dry type 3

transformers, series – and stunt reactor, capacitor tanks, vacuum – and SF circuit b reakers gas insulated switch gears and insulators. A strong engineering base ena bles 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 system s (for economic transfer of bulk power). BHEL has indigenously developed the sta te-of-the-art controlled shunt reactor (for reactive power management on long tr ansmission lines). Presently a 400 kV Facts (Flexible AC Transmission System) pr oject under execution. 1.2.3. INDUSTRIES BHEL is a major contributor of equipmen t and systems to industries. Cement, sugar, fertilizer, refineries, petrochemica ls, paper, oil and gas, metallurgical and other process industries lines and imp roving 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-theart controlled shun t reactor (for reactive power management on long transmission lines). Presently a 400 kV FACTS (Flexible AC Transmission System) projects is under execution. Th e range of system & equipment supplied includes: captive power plants, cogenerat ion plants DG power plants, industrial steam turbines, industrial boilers and au xiliaries. Water heat recovery boilers, gas turbines, heat exchangers and pressu re vessels, centrifugal compressors, electrical machines, pumps, valves, seamles s steel tubes, electrostatic precipitators, fabric filters, reactors, fluidized bed combustion boilers, chemical recovery boilers and process controls. The Comp any is a major producer of large-size thruster devices. It also supplies digital distributed control systems for process industries, and control & instrumentati on 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 o ther applications. 4

The Company has commenced manufacture of large desalination plants to help augme nt the supply of drinking water to people. 1.2.4. TRANSPORTATION BHEL is involve d in the development design, engineering, marketing, production, installation, m aintenance and after-sales service of Rolling Stock and traction propulsion syst ems. 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 a nd shunting duly applications. BHEL is also producing rolling stock for special applications viz., overhead equipment cars, Special well wagons, Rail-cum-road v ehicle etc., Besides traction propulsion systems for in-house use, BHEL manufact ures traction propulsion systems for other rolling stock producers of electric l ocomotives, diesel-electric locomotives, electrical multiple units and metro car s. The electric and diesel traction equipment on India Railways are largely powe red by electrical propulsion systems produced by BHEL. The company also undertak es retooling and overhauling of rolling stock in the area of urban transportatio n systems. BHEL is geared up to turnkey execution of electric trolley bus system s, light rail systems etc. BHEL is also diversifying in the area of port handing equipment and pipelines transportation system. 1.2.5. TELECOMMUNICATION BHEL al so caters to Telecommunication sector by way of small, medium and large switchin g systems. 1.2.6. RENEWABLE ENERGY Technologies that can be offered by BHEL for exploiting non-conventional and renewable sources of energy include: wind electr ic generators, solar photovoltaic systems, solar lanterns and battery-powered ro ad vehicles. The Company has taken up R&D efforts for development of multi-junct ion amorphous silicon solar cells and fuel based systems. 5

1.2.7. INTERNATIONAL OPERATIONS BHEL has, over the years, established its refere nces in around 60 countries of the world, ranging for the United States in the w est 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 ga s-based types, substation projects, rehabilitation projects, besides a wide variety of products, like transformers, insulators, swi tchgears, heat exchangers, castings and forgings, valves, well-head equipment, c entrifugal compressors, photo-voltaic equipment etc. apart from over 1110mw of b oiler 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, Banglades h, Azerbaijan, Sri Lanka, Iraq etc. The company has been successful in meeting d emanding customer s requirements in terms of complexity of the works as well as technological, quality and other requirements viz. extended warrantees, associat ed O&M, financing packages etc. BHEL has proved its capability to undertake proj ects on fast-track basis. The company has been successful in meeting varying nee ds of the industry, be it captive power plants, utility power generation or for the oil sector requirements. Executing of overseas projects has also provided BH EL the experience of working with world renowned consulting organizations and in spection agencies. In addition to demonstrated capability to undertake turnkey p rojects on its own, BHEL possesses the requisite flexibility to interface and co mplement with international companies for large projects by supplying complement ary equipment and meeting their production needs for intermediate as well as fin ished 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. 6

1.3. TECHNOLOGY UPGRADATION AND RESEARCH & DEVELOPMENT To remain competitive and meet customers expectations, BHEL lays great emphasis on the continuous up gra dation of products and related technologies, and development of new products. Th e Company has upgraded its products to contemporary levels through continuous in house efforts as well as through acquisition of new technologies from leading e ngineering 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 are as of importance to BHEL s product range. Research and product development cente rs at each of the manufacturing divisions play a complementary role. BHEL s Inve stment 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 reve nues 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 fluidiz ed bed combustion boilers, high-efficiency Pelton hydro turbines, petroleum depo t automation systems, 36 kV gas-insulated sub-stations, etc. The Company has als o transferred a few technologies developed in-house to other Indian companies fo r commercialization. Some of the on-going development & demonstration projects i nclude: Smart wall blowing system for cleaning boiler soot deposits, and micro-c ontroller based governor for diesel-electric locomotives. The company is also en gaged in research in futuristic areas, such as application of super conducting m aterials in power generations and industry, and fuel cells for distributed, envi ronment-friendly power generation. 1.3.1 HUMAN RESOURCE DEVELOPMENT INSTITUTE Th e most prized asset of BHEL is its employees. The Human Resource Development Ins titute and other HRD centers of the Company help in not only keeping their skill s updated and finely honed but also in adding new skills, whenever required. Con tinuous training and retraining, positive, a positive work culture and participa tive 7

style of management, have engendered development of a committed and motivated wo rk force leading to enhanced productivity and higher levels of quality. 1.4. HEA LTH, SAFETY AND ENVIRONMENT MANAGEMENT BHEL, as an integral part of business per formance 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 establ ishment, and to providing safe and healthy working environment to all its employ ees. For fulfilling these obligations, Corporate Policies have been formulated a s: 1.4.1. ENVIRONMENTAL POLICY Compliance with applicable Environmental Legislat ion/Regulation; Continual Improvement in Environment Management Systems to prote ct our natural environment and Control Pollution; Promotion of activities for co nservation of resources by Environmental Management; Enhancement of Environmenta l awareness amongst employees, customers and suppliers. BHEL will also assist an d co-operate with the concerned Government Agencies and Regulatory Bodies engage d in environmental activities, offering the Company s capabilities is this field . 1.4.2. OCCUPATIONAL HEALTH AND SAFETY POLICY Compliance with applicable Legisl ation and Regulations; Setting objectives and targets to eliminate/control/minim ize risks due to Occupational and Safety Hazards; Appropriate structured trainin g of employees on Occupational Health and Safety (OH&S) aspects; 8

Formulation and maintenance of OH&S Management programs for continual improvemen t; Periodic review of OH&S Management System to ensure its continuing suitabilit y, adequacy and effectiveness; Communication of OH&S Policy to all employees and interested parties. The major units of BHEL have already acquired ISO 14001 Env ironmental Management System Certification, and other units are in advanced stag es of acquiring the same. Action plan has been prepared to acquire OHSAS 18001 O ccupational Health and Safety Management System certification for all BHEL units . In pursuit of these Policy requirements, BHEL will continuously strive to impr ove work particles in the light of advances made in technology and new understan dings in Occupational Health, Safety and Environmental Science. Participation in the "Global Compact" of the United Nations. The "Global Compact" is a partnersh ip between the United Nations, the business community, international labor and N GOs. It provides a forum for them to work together and improve corporate practic es through co-operation rather than confrontation. BHEL has joined the "Global C ompact" of United Nations and has committed to support it and the set of core va lues enshrined in its nine principles: 1.4.3. PRINCIPLES OF THE "GLOBAL COMPACT" HUMAN RIGHTS 1. Business should support and respect the protection of internati onally proclaimed human rights; and 2. Make sure they are not complicit in human rights abuses. 9

LABOUR STANDARDS 3. Business should uphold the freedom of association and the ef fective recognition of the right to collective bargaining; 4. The elimination of all form of forces and compulsory labor. 5. The effective abolition of child la bor, 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 t echnologies. By joining the "Global Compact", BHEL would get a unique opportunit y of networking with corporate and sharing experience relating to social respons ibility on global basis. and diffusion of environmentally friendly 10

1.5. BHEL UNITS UNIT 1. Bhopal TYPE Heavy Electrical Plant PRODUCT Steam turbine s , Turbo generators , Hydro sets , Switch gear controllers 2. Haridwar HEEP CFF P Heavy Electrical Equipment Plant Central Foundry Forge Plant 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 gener ating set 4.Tiruchi HPBP SSTP High Pressure Boiling Plant Steam less steel tubes , Spiral fin welded tubes. Hydro turbines , Steam turbines, Gas turbine, Turbo g enerators, Heavy castings and forging. Control panels, Light aircrafts, Electric al machines 5.Jhansi TP Transformer Plant Transformers, Diesel shunt less AC locos and AC EM U 11

6.Banglore EDN EPD Control Equipment Division Electro Porcelain Division Energy meters, Water meters , Control equipment, Capacitors , Photovoltaic panel s, Simulator , Telecommunication system, Other advanced micro processor based co ntrol system. Insulator and bushing, Ceramic liners. 7.Ranipet BAP Boiler Auxiliaries Plant Electrostatic precipitator, Air pre-heate r, Fans, Wind electric generators, Desalination plants. 8.Goindwal 9.Jagdishpur IP Insulator Plant. High tension ceramic, Insulation Plates and bushings 10.Rudr apur Component Fabrication Plant 11.Gurgoan Amorphous Silicon Solar Cell Plant. Solar Photovoltaic Cells, Solar lanterns chargers , Solar clocks Windmill, Solar water heating system Industrial Valves Plant Industrial valves and Fabrication TABLE1 12

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 u nits, namely Heavy Electrical Equipment Plant (HEEP) and Central Foundry Forge P lant (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 manu facturing plants of BHEL. The core business of HEEP includes design and manufact ure of large steam and gas turbines, turbo generators, hydro turbines and genera tors, large AC/DC motors and so on. Central Foundry Forge Plant (CFFP) is engage d 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 a s followed: 1) Heavy Electrical Equipment Plant (HEEP) 2) Central Foundry Forge Plant (CFFP). 13

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 part s VI. Fabrication Stamping and die manufacturing Fabricated oil tanks, hollow guide blades, Rings, stator frames and rotor spindl e, all dies, stamping for generators motors and 14

VII. Wood working VIII. Heaters & coolers Wooden packing, spacers. LP heaters, ejectors, glands, steam and oil coolers, Oi l 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 15

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 cy cle. 2. GAS TURBINES: Gas turbines for industry and utility application; range-3 to 2 00 MW (ISO). Gas turbines based co-generation and combined cycle system . 3. HYDRO SETS: Custom– built conventional hydro turbine of Kaplan, Francis and Pel ton with matching generators up to 250 MW unit size. Pump turbines with matching motor-generators. Mini / micro hydro sets. Spherical butterfly and rotary valve s 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 excha ngers 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. 16

6. CONTROL PANEL: Control panel for voltage up to 400KW and control desks for ge nerating stations and EMV sub–stations. 7. CASTING AND FORGINGS: Sophisticated heavy casting and forging of creep resist ant alloy steels, stainless steel and other grades of alloy meeting stringent in ternational specifications. 8. DEFENCE: Naval guns with collaboration of Italy. 17

2. STEAM TURBINE 2.1 INTRODUCTION A turbine is a device that converts chemical energy into mechan ical 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 possibl e because the water to steam conversion results in a rapidly expanding gas. As t he turbine’s rotor turns, the rotating shaft can work to accomplish numerous appli cations, 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 ine fficiencies incurred in the process. Since the fluid is at a lower pressure at t he 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 flo w 18

occurs at the turbine exit (at least for compressible fluids) leading to the nee d for larger turbine exit areas than at the inlet. The generic symbol for a turb ine 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 sy mbol from a compressor symbol. In Figure , the graphic is colored to indicate th e 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 turb ine 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 extr act energy from the exhaust gases of a large diesel engine, but the fluid in a b ottoming cycle still has sufficient energy to be extracted across a turbine, wit h 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 small er hydrokinetic turbines currently being designed for and demonstrated in river and tidal applications. Turbines can be designed to work well in a variety of fl uids, including gases and liquids, where they are used not only to drive generat ors, but also to drive compressors or pumps. 19

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 typica lly 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 ga s turbine still provides power, but a compressor and combustor are required to m ake a selfcontained system that needs only the fuel to burn in the combustor. An additional use for turbines in industrial applications that may also be applica ble in some green energy systems is to cool a fluid. As previously mentioned, wh en a turbine extracts energy from a fluid, the fluid temperature is reduced. Som e industries, such as the gas processing industry, use turbines as sources of re frigeration, dropping the temperature of the gas going through the turbine. In o ther words, the primary purpose of the turbine is to reduce the temperature of t he working fluid as opposed to providing power. Generally speaking, the higher t he pressure ratio across a turbine, the greater the expansion and the greater th e temperature drop. Even where turbines are used to cool fluids, the turbines st ill 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 applicatio ns are sometimes called expanders. The terms “turbine” and “expander” can be used interc hangeably for most applications, but expander is not used when referring to kine tic energy applications, as the fluid does not go through significant expansion. 2.2. ADVANTAGES:Ability to utilize high pressure and high temperature steam. Hig h efficiency. High rotational speed. High capacity/weight ratio. Smooth, nearly vibration-free operation. No internal lubrication. Oil free exhausts steam. 20

2.3 DISADVANTAGES:For slow speed application reduction gears are required. The s team turbine cannot be made reversible. The efficiency of small simple steam tur bines is poor. 2.4 STEAM TURBINES THE MAINSTAY OF BHEL BHEL has the capability to design, manuf acture and commission steam turbines of up to 1000 MW rating for steam parameter s ranging from 30 bars to 300 bars pressure and initial & reheat temperatures up to 600
C. 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 s team parameters appropriate turbine blocks can be selected. 21

3. TYPES OF STEAM TURBINE There are complicated methods to properly harness steam power that give rise to the two primary turbine designs: impulse and reaction turbines. These different designs engage the steam in a different method so as to turn the rotor 3.1 IMPUL SE TURBINE The principle of the impulse steam turbine consists of a casing conta ining stationary steam nozzles and a rotor with moving or rotating buckets. The steam passes through the stationary nozzles and is directed at high velocity aga inst rotor buckets causing the rotor to rotate at high speed. The following even ts take place in the nozzles: 1. The steam pressure decreases. 2. The enthalpy o f the steam decreases. 3. The steam velocity increases. 4. The volume of the ste am increases. 5. There is a conversion of heat energy to kinetic energy as the h eat 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 pres sure 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 ap plied 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 wi ll 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 appli ed to the blade is developed by causing the steam to change direction of flow (N ewton’s 2nd Law – change of momentum). The change of momentum produces the impulse f orce. The fact that the pressure does not drop across the moving blades is the d istinguishing feature of the impulse turbine. The 22

pressure at the inlet to the moving blades is the same as the pressure at the ou tlet 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 pr essure. 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 TU RBINE STAGING In order for the steam to give up all its kinetic energy to the mo ving blades in an impulse turbine, it should leave the blades at zero absolute v elocity. 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 v elocity, the following methods may be used: 1. Pressure compounding. 2. Velocity compounding. 3. Pressure-velocity compounding. 4. Pressure Compounding 23

4. TURBINE PARTS 4.1 TURBINE BLADES Cylindrical reaction blades for HP, IP and LP Turbines 3-DS b lades, in initial stages of HP and IP Turbine, to reduce secondary losses. Twist ed 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 bl ades Tip sections with supersonic design o o Fir-tree root Flame hardening of th e 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 Casing s 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 cylinde r walls. However, for assembling and inspection purposes there is no other solut ion. The casing is heavy in order to withstand the high pressures and temperatur es. It is general practice to let the thickness of walls and flanges decrease fr om inlet- to exhaust-end. The casing joints are made steam tight, without the us e of gaskets, by matching the flange faces very exactly and very smoothly. The b olt 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 ar e 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 out er casings. 24

4.3 TURBINE ROTORS The design of a turbine rotor depends on the operating princi ple 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 moun ted in diaphragms with labyrinth seals around the shaft. This construction requi res 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 shoul d give the strongest rotor and a fully balanced rotor. It is rather expensive, a s the weight of the final rotor is approximately 50% of the initial forging. Old er 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 diamete r 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 c learance between the discs prevents thermal stress in the shaft. DRUM ROTORS The first reaction turbines had solid forged drum rotors. They were strong, general ly well balanced as they were machined over the total surface. With the increasi ng 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 e nd. The second part of the rotor is the drum end cover with shaft. 25

5. CONSTRUCTIONAL FEATURES OF A BLADE The blade can be divided into 3 parts: The profile, which converts the thermal e nergy 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 p roper anchor to the blade, and transmitting the kinetic energy of the blade to t he rotor. The damping element, which reduces the vibrations which necessarily oc cur in the blades due to the steam flowing through the blades. These damping ele ments may be integral with blades, or they may be separate elements mounted betw een the blades. Each of these elements will be separately dealt with in the foll owing sections. 5.1 H.P. BLADE PROFILES In order to understand the further expla nation, a familiarity of the terminology used is required. The following termino logy is used in the subsequent sections. CAMBER LINE CHORD BITANGENT LINE FIG.3 HIGH PRESSURE BLADE PROFILE 26

If circles are drawn tangential to the suction side and pressure side profiles o f a blade, and their centers are joined by a curve, this curve is called the cam ber line. This camber line intersects the profile at two points A and B. The lin e joining these points is called chord, and the length of this line is called th e chord length. A line which is tangential to the inlet and outlet edges is call ed 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 d istance between any point on the profile and an identical point on the next blad e. 5.2 CLASSIFICATION OF PROFILES There are two basic types of profiles - Impulse a nd 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 d rop of the stage is distributed almost equally between the guide and moving blad es. 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 impu lse stages in practice have a small degree of reaction. These stages are therefo re more accurately, though less widely, described as low-reaction stages. The pr esently used reaction profiles are more efficient than the impulse profiles at p art 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 pres sure-side profile of the blade, the losses are low. However, the impulse profile s have one advantage. The impulse profiles can take a large heat drop across a s ingle stage, and the same heat drop would require a greater number of stages if reaction profiles are used, thereby increasing the turbine length. 27

The Steam turbines use the impulse profiles for the control stage (1st stage), a nd the reaction profiles for subsequent stages. There are three reasons for usin g impulse profile for the first stage. a) Most of the turbines are partial arc admission turbines. If the first stage i s a reaction stage, the lower half of the moving blades do not have any inlet st eam, 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 th at the wheel chamber of the outer casing is not exposed to the high inlet parame ters. In case of -4 turbines, the inner casing parting plane strength becomes th e 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) T he 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 inle t steam to the first reaction stage is properly mixed, and occupies the entire 3 60 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 stag es to make the turbine short, or to increase the part load efficiency by using n ozzle 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 dep ends upon the centrifugal and steam bending forces of the blade. It should be de signed such that the material in the blade root as well as the rotor / stator cl aw 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 th e T-root. It was found that 28

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 tur bine applications are shown in the following figure: T-ROOT T-ROOT WITH SIDE GRIP FORK ROOT TABLE 4 BLADE ROOTS 29

5.4 L.P. BLADE PROFILES The LP blade profiles of moving blades are twisted and t apered. 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 roo ts of both the LP stages in –2 type of LP blading are T-roots. 2) 3 blading: The l ast stage LP blade of HK, SK and LK blades have a fork-root. SK blades have 4-fo rk roots for all sizes. HK blades have 4-fork roots up to 56 size, where modifie d profiles are used. Beyond this size, HK blades have 3 fork roots. LK blades ha ve 3-fork roots for all sizes. The roots of the LP blades of preceding stages ar e of T-roots. 5.6 DYNAMICS IN BLADE The excitation of any blade comes from different sources. They are: a) Nozzle-pa ssing excitation: As the blades pass the nozzles of the stage, they encounter fl ow disturbances due to the pressure variations across the guide blade passage. T hey also encounter disturbances due to the wakes and eddies in the flow path. Th ese 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 e xcitation. The order of this frequency = no. of guide blades x speed of the mach ine. Multiples of this frequency are considered for checking for resonance. b) Excitation due to non-uniformities in guide-blades around the periphery. Thes e can occur due to manufacturing inaccuracies, like pitch errors, setting angle variations, inlet and outlet edge variations, etc. 30

For HP blades, due to the thick and cylindrical cross-sections and short blade h eights, the natural frequencies are very high. Nozzle-passing frequencies are th erefore necessarily considered, since resonance with the lower natural frequenci es occurs only with these orders of excitation. In LP blades, since the blades a re thin and long, the natural frequencies are low. The excitation frequencies to be considered are therefore the first few multiples of speed, since the nozzlepassing frequencies only give resonance with very high modes, where the vibratio n 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 sh rouds 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 t he vibrations. When vibrations occur, the vibration energy is dissipated as fric tion between shrouds of adjacent blades. For HP guide blades of Wesel design, the shroud is not integral, but a shroud ba nd 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 integ ral shrouds like moving blades. The primary function remains steam sealing. In industrial turbines, in LP blades, the resonant vibrations have high amplitud es due to the thin sections of the blades, and the large lengths. It may also no t always be possible to avoid resonance at all operating conditions. This is bec ause 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 th e 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 t ime. 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 31

also, it is not possible to avoid resonance. In such cases, where it is not poss ible to avoid resonance, a damping element is to be used in the LP blades to red uce the dynamic stresses, so that the blades can operate continuously under reso nance also. There may be blades which are not adequately damped due to manufactu ring inaccuracies. The need for a damping element is therefore eliminated. In ca se the frequencies of the blades tend towards resonance due to manufacturing ina ccuracies, tuning is to be done on the blades to correct the frequency. This tun ing 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 t he base of the profile (which reduces the stiffness more than the inertia) to re duce the natural frequency. The damping in any blade can be of any of the following types: a) Material dampi ng: This type of damping is because of the inherent damping properties of the ma terial 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 dam ping: This is due to the rubbing friction between the component under considerat ion with any other object. Out of these damping mechanisms, the material and aer odynamic types of damping are very small in magnitude. Friction damping is enorm ous as compared to the other two types of damping. Because of this reason, the d amping elements in blades generally incorporate a feature by which the vibration al energy is dissipated as frictional heat. The frictional damping has a particu lar characteristic. When the frictional force between the rubbing surfaces is ve ry small as compared to the excitation force, the surfaces slip, resulting in fr iction damping. However, when the excitation force is small when compared to the frictional force, the surfaces do not slip, resulting in locking of the surface s. This condition gives zero friction damping, and only the material and aerodyn amic damping exists. In a periodically varying excitation force, it may frequent ly happen that the force is less than the friction force. During this phase, the damping is very 32

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 i ndividual value. The response therefore also changes in the locked condition. Th e 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 th e system, i.e., the relative magnitude of excitation and friction forces) and th e natural frequency of the system (which alters between the individual values an d 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 a lloy. The 403 stainless steel is essentially the industry’s standard blade materia l 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, duc tility, toughness, erosion and corrosion resistance, and damping. It is used wit hin 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 temperatur e 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 g as expanders with stage temperatures between 900 and 1150°F (482 and 621°C). The Hay nes Stellite Alloy Number 31 is a cobalt-based super alloy and is used on jet ex panders 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 mat erial is titanium. Its high strength, low density, and good erosion resistance m ake it a good candidate for high speed or long-last stage blading. 33

6. MANUFACTURING PROCESS 6.1 INTRODUCTION Manufacturing process is that part of the production process wh ich is directly concerned with the change of form or dimensions of the part bein g 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 dimension s of the part produced. Manufacturing is the backbone of any industrialized nati on. Manufacturing and technical staff in industry must know the various manufact uring processes, materials being processed, tools and equipments for manufacturi ng different components or products with optimal process plan using proper preca utions 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 facilit ies needed to be positioned properly for optimal shop layouts or plant layout an d other support services effectively adjusted or located in the industry or plan t within a well planned manufacturing organization. Today’s competitive manufactur ing era of high industrial development and research, is being called the age of mechanization, automation and computer integrated manufacturing. Due to new rese arches in the manufacturing field, the advancement has come to this extent that every different aspect of this technology has become a fullfledged fundamental a nd advanced study in itself. This has led to introduction of optimized design an d manufacturing of new products. New developments in manufacturing areas are dec iding to transfer more skill to the machines for considerably reduction of manua l 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 product s, tools, machines and equipments in factories or industries are for providing c ommercial castings, called ingots. Such ingots are then processed in 34

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 variou s manufacturing processes for getting usable metal products of different shapes and sizes in various manufacturing shops. All these processes used in manufactur ing concern for changing the ingots into usable products may be classified into six major groups as Primary shaping processes Secondary machining processes Meta l 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 th ese processes may or may not require to undergo further operations. Some of the important primary shaping processes are: (1) Casting (2) Powder metallurgy (3) P lastic technology (4) Gas cutting (5) Bending and (6) Forging. 35

6.2.2 SECONDARY OR MACHINING PROCESSES As large number of components require fur ther processing after the primary processes. These components are subjected to o ne or more number of machining operations in machine shops, to obtain the desire d shape and dimensional accuracy on flat and cylindrical jobs. Thus, the jobs un dergoing these operations are the roughly finished products received through pri mary shaping processes. The process of removing the undesired or unwanted materi al from the work-piece or job or component to produce a required shape using a c utting tool is known as machining. This can be done by a manual process or by us ing a machine called machine tool (traditional machines namely lathe, milling ma chine, drilling, shaper, planner, slotter). In many cases these operations are p erformed on rods, bars and flat surfaces in machine shops. These secondary proce sses are mainly required for achieving dimensional accuracy and a very high degr ee of surface finish. The secondary processes require the use of one or more mac hine tools, various single or multi-point cutting tools (cutters), job holding d evices, marking and measuring instruments, testing devices and gauges etc. for g etting desired dimensional control and required degree of surface finish on the workpieces. The example of parts produced by machining processes includes hand t ools 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 t he common secondary or machining processes are: Turning Threading Knurling Milli ng Drilling Boring Planning Shaping Slotting Sawing 36

Broaching Hobbing Grinding Gear Cutting Thread cutting and Unconventional machin ing processes namely machining with Numerical control (NC) machines tools or Com puter Numerical Control(CNC) machine tool using ECM, LBM, AJM, USM setups. 37

7. BLOCK 3 LAY-OUT TABLE5 LAYOUT OF BLOCK-3 38

8. CLASSIFICATION 1. HMS OF BLOCK 3 BAY-1 IS FURTHER DIVIDED INTO THREE PARTS In this shop heavy machine work is done with the help of different NC & CNC mach ines such as center lathes, vertical and horizontal boring & milling machines. A sia’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 turbin es are done. Blades of turbine are 1st assemble on the rotor & after it this rot or is transported to balancing tunnel where the balancing is done. After balanci ng the rotor, rotor & casings both internal & external are transported to the cu stomer. 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 turb ines 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 place d on pedestal and rotted with speed of 2500-4500 rpm. After it in a computer con trol room the axis of rotation of rotor is seen with help of computer & then bal ance the rotor by inserting the small balancing weight in the grooves cut on rot or. 39

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 unde r 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 throu gh different NC & CNC machines like grinding, drilling, vertical & horizontal mi lling and boring machines, center lathes, planer, Kopp milling machine. 2 .Assem bly 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 guid e blades are assembled inside the internal casing & 40

then rotor is fitted inside this casing. After it this internal casing with roto r is inserted into the external. BAY 3 IS DIVIDED INTO 3 PARTS: 1. Bearing section – In this section Journal bearin gs are manufactured which are used in turbines to overcome the vibration & rolli ng friction by providing the proper lubrication. 2. Turning section – In this sect ion small lathe machines, milling & boring machines, grinding machines & drillin g machines are installed. In this section small jobs are manufactured like rings , studs, disks etc. 3. Governing section – In this section governors are manufactu red. These governors are used in turbines for controlling the speed of rotor wit hin the certain limits. 1st all components of governor are made by different ope rations then these all parts are treated in heat treatment shop for providing th e 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 thi s shop solid blade of both steam & gas turbine are manufactured. Several CNC & N C machines are installed here such as Copying machine, Grinding machine, Rhomboi d milling machine, Duplex milling machine, T- root machine center, Horizontal to oling center, Vertical & horizontal boring machine etc. 41

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 mac hines, milling, boring, grinding machines etc. FIG.6 CNC ROTOR TURNING LATHE Heat treatment shopIn this section there are sever al tests performed for checking the hardness of different components. Tests perf ormed are Sterelliting, Nitriding, DP test. 42

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 p erform 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 L P TURBINE BLADES is generally greater than that of HP TURBINE BLADES. At the fir st 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 mod ern blades are F & Z shaped blades. FIG.7 TYPES OF BLADES 43

9.2 OPERATIONS PERFORMED ON BLADES Some of the important operations performed on blade manufacturing are:Milling Blank Cutting Grinding of both the surfaces Cut ting 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 44

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 comple te 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 sha ping machine FIG.9 CNC SHAPING MACHINE 45

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 En gineer of department Mr. A.K. KHUSHWAHA situated in Ranipur, Haridwar, Uttarakha nd. The training was specified under the Turbine Manufacturing Department. Worki ng under the department I came to know about the basic grinding, scaling and mac hining processes which was shown on heavy to medium machines. Duty lathes were p lanted in the same line where the specified work was undertaken. The training br ought to my knowledge the various machining and fabrication processes went not o nly in the manufacturing of blades but other parts of the turbine. 46