A Report on industrial training at
“BHARAT HEAVY ELECTRICALS LIMITED”Haridwar, India.
Manufacture and assembly of Turbo Generators and
Exciter motors
Under the able guidance of
Sh. P.S. Jangpangi (Sr. DGM) – Block 1
Submitted by
Gurtej Singh B. Tech 4th year
Department of Electrical Engineering IIT ROORKEE,India
Uttar Pradesh, India
ACKNOWLEDGEMENT
Practical knowledge means the visualization of the knowledge, which we read in our books. For this, we perform experiments and get observations. Practical knowledge is very important in every field. One must be familiar with the problems related to that field so that he may solve them and become a successful person.
After achieving the proper goal in life, an engineer has toenter in professional life. According to this life, he has to serve anindustry, may be public or private sector or self-own. For the efficientwork in the field, he must be well aware of the practical knowledgeas well as theoretical knowledge.
To be a good engineer, one must be aware of the industrial environment and must know about management, working in such a industry, labor problems etc., so that he can tackle them successfully.
Due to all the above reasons and to bridge the gap between theory and practical, our engineering curriculum provides a practical training of 30 days. During this period, a student works in the industry and gets all type of experience and knowledge about the working and maintenance of various types of machinery.
I have undergone my 30 days training (after VI Semester) atBHARAT HEAVY ELECTRICALS LIMITED. This report is based on the knowledge, which I acquired during my 30 days training period at the plant.
UTSAV GOYAL
INDEX
S.No.
1. INTRODUCTION
2. BHEL-A Brief Profile
3. BHEL - AN OVERVIEW
4. HEEP: AN OVERVIEW
5. BRIEF SUMMARY OF THE BAR SHOP
6. TYPES OF TURBOGENERATORS
7. MATERIAL CHECKING
8. CONDUCTOR CUTTING AND END CLEANING
9. TRANSPOSITION OF CONDUCTORS
10. CROSSOVER INSULATION
11. PRESSING
12. ISS- TEST
13. FORMING OF BAR
14. ZERO PICKLING OF BAR END
15. COIL LUG MOUNTING
16. MAIN BRAZING
17. CONDUCTOR CUTTING, DEBBERING AND FACE MILLING
`18. FIRST PICKLING
19 BRAZING OF TOP PART
20. WATER FLOW TEST
21. NITROGEN LEAK TEST
22 THERMAL SHOCK TEST
23 HELIUM LEAKAGE TEST
24. INSULATION
25. IMPREGNATION AND BAKING
26. FINISHING
27. CONDUCTING VARNISH COATING
28. TESTING
28.1 TAN-DELTA TEST
28.2HIGH VOLTAGE TEST
29. DISPATCHED FOR WINDING
30. MOTOR WINDING
31. CONCLUSION
INTRODUCTION
In 1956, India took a major step towards theestablishment of its heavy engineering industry when BharatHeavy Electrical Ltd., the first heavy electrical manufacturing unitof the country was setup at Bhopal. It progressed rapidly and three morefactories went into production in 1965. The main aim of establishing BHEL was to meet the growing power requirement of the country.
B.H.E.L appeared on the power map of India in 1969 when the first unit supplied by it was commissioned at the Basin Bridge Thermal Power Station in Tamil Nadu. Within a decade, BHEL had commissioned the 100 unit at Santaldih. West Bengal.BHEL had taken India from a near total dependence on imports to complete self-reliance in this vital area of power plant equipmentBHEL has supplied 97% of the power generating equipment. BHELhas already supplied generating equipment to various utilities capableof generating over 18000 MW power. Today BHEL can produce annually; equipment capable of generating 6000MW. This will grow further to enable BHEL to meet all of India’s projected power equipment requirement. As well as sizeable portion of export targets.
Probably the most significant aspect of BHEL’s growth has been it’sdiversification. The constant reorientation of the organization to meet thevaried needs intime with time a philosophy that has led to the development of atotal capability from concepts to commissioning not only in the fieldof energy but also in industry and transportation.
In the world power scene, BHEL ranks among the top ten manufactures of power plant equipment and in terms of the spectrum of products and services offered, it is right on top. BHEL’s technological excellence and turnkey capabilities have won it worldwide recognition. Over 40 countries in the world over have placed orders with BHEL
covering individual equipment to complete power stations on a turnkey basis.
In 1978-79 export earnings reached Rs. 122 crores, the highest forany one-year.BHEL has its headquarters at New Delhi. Its operations arespread over 11manufacturing plants and number of engineering and service divisions located across thecountry/ the service divisions includes a network of regional branch offices throughoutIndia.
BHEL-A Brief Profile
BHEL is the largest engineering and manufacturing enterprise in India in the energy-related / infrastructure sector, today. BHEL is ushering in the indigenous Heavy Electrical Equipment industry in India-a dream that has been more than realized with a well-recognized track record of Performa
A widespread network comprising of 14 manufacturing companies, which have international recognition for its commitment towards quality. With an export presence in more than 60 countries, BHEL is truly India’s ambassador to the world. BHEL’s vision is to become world class engineering enterprise, committed to enhancing stakeholder value.
BHEL has:-
Installed equipment for over 90,000MW of power generation
for Utilities, captive and Industrial users.
Supplied over 25000 Motors with Drive Control System to
power projects, Petrochemicals Refineries, Steel, Aluminum,
Fertilizer, Cement plant, etc.
Supplied Traction electrics and AC/DC locos over 12000 kms
Railway network.
Supplied over one million Values to Power Plants and other
Industries
BHEL - AN OVERVIEW
The first plant of what is today known as BHEL was established nearly 40 years ago at Bhopal & was the genesis of the Heavy Electrical Equipment industry in India.
BHEL is today the largest Engineering Enterprise of its kind in India with excellent track record of performance, making profits continuously since 1971-72.
BHEL business operations cater to core sectors of the Indian Economy like.
Power
Industry
Transportation
Transmission
Defenses etc.
Today BHEL has
14 Manufacturing Divisions
9 Service Centers
4 Power Sector Regional
Centers 150 Project sites
BHEL’s vision is to become world -class engineering enterprise,committed to enhancing stakeholder value. The greatest strength ofBHEL is its highly skilled and committed 44,000 employees.
Spread all over India & abroad to provide prompt and effective service to customers.
BUSINESS SECTOR
BHEL operations are organized around business sectors to provide a strong market orientation. These business sectors are Power Indus and International operations.
POWER SECTOR
Power sector comprises of thermal, nuclear, gas and hydro business. Today BHEL supplied sets account for nearly 65% of the total installed capacity in the country as against nil till 1969-70.
BHEL has proven turnkey capabilities for executing power projects from concept to commissioning and manufactures boilers, thermal turbine generator set and auxiliaries up to 500MW.
It possesses the technology and capability to procure thermal power generation equipment up to 1000MW.
Co-generation and combined cycle plants have also been introduced.
For efficient use of the high ash content coal-BHEL supplies circulating fluidized boiler.
BHEL manufactures 235MW nuclear sets and has also commenced production of 500MW nuclear set.
Custom-made huge hydro sets of Francis, Elton and Kaplan types for different head- discharge combinations are also engineered and manufactured by BHEL.
INDUSTRY SECTOR
BHEL is a major contributor of equipment and system to important industries like
Cement
Petrochemicals
Fertilizers
Steel paper
Refineries
Mining and Telecommunication
The range of system and equipment supplied including captive power stations
High speed industrial drive turbines
Industrial boilers and auxiliaries
Waste heat recovery boilers
Gas turbines pump, valves, seamless steel
tubes Heat exchangers
Process control etc.
TRANSPORATION :-
BHEL supplies a wide equipment and system to Indian Railways.
Electric locomotive
Traction electric and traction control equipment
TELECOMMUNICATION:-
BHEL also caters to Telecommunication sector by way of small, medium and large switching system.
BHEL has been divided into many blocks:-
1). Block-1:-In block one turbo generator, generator, exciter motors
(A.C&D.C) are manufactured & assembled
2). Block-2:-In block two large size fabricated assemblies\component for
power equipment are manufactured & assembled.
3) Block-3:-In block -3 steam turbine, hydro turbines, and gas turbines,
turbines blade are manufactured & assembled
4) Block-4:-In block -4winding for turbo generator, hydro generator,
insulation of A.C&D.C motors insulating component for turbo generator, hydro generator motors are manufactured & assembled
5) Block-5:-In block - 5 fabricated parts of steam turbine water box, hydro
turbine turbines parts are manufactured & assembled
6) Block-6:-In block -6 fabricated oil tanks hollow guide blades, rings,
stator frames rotor spiders are manufactured & assembled
7) Block-7:-
In block -7all types of dies including stamping dies, stampingfor generators&motors are manufactured & assembled
8) Block-8:-In block -8 LP heaters, ejectors, steam coolers, oil coolers,
ACG coolers, oil tanks are manufactured & assembled
MANUFACTURING DIVISIONS
Heavy Electrical Plant, Piplani, Bhopal
Electrical Machines Repair Plant (EMRP), Mumbai
Transformer Plant P.O. BHEL, Jhansi.
Bharat Heavy Electrical Limited :
Central Foundry Forge Plant., Ranipur,
Hardwar Heavy Equipment Repair Plant, Varanasi.
Insulator Plant, Jagdishpur, Distt. Sultanpur.
Heavy Power Equipment Plant, Ramachandra Puram, Hyderabad
High Pressure Boiler Plant & Seamless Steel Tube Plant,
Tiruchirappalli.
Boiler Auxiliaries Plant, Indira Gandhi Industrial Complex,
Ranipet. Industrial Valves Plant, Goindwal.
Electronics Division :
Electronics Systems Division.
Amorphous Silicon Solar Cell Plant
(ASSCP). Electro porcelains Division.
HEEP: AN OVERVIEW
Over the years, Bharat Heavy Electrical Limited has emergedas world class engineering and Industrial giant, the best of its kind inentire South East Asia. Its business profile cuts across various sectorsof engineering/power utilities and industry. The company todayenjoys national and international presence featuring in the " fortune international-500” and is ranked among the top 12 companies of the world, manufacturing power generation equipment. BHEL has now 14manufacturing division, 8 service centers and 4power power sectorsregional centers besides a large number of project sites spread overIndia and abroad.
The company is embarking upon an ambitious growth path through clear vision, mission and committed values to sustain and augment its image as a world-class enterprise.
VISION
A world-class innovating, competitive and profitableengineering enterprise providing total business solution.
MISSION
To be the leading Indian engineering enterprise providing qualityproducts system and services in the field of energy, transportation,infrastructure and other potential areas.
VALUES
Meeting commitments made to external & internal customers
Foster learning creative and speed of response
Respect for dignity and potential of individual
Loyalty and pride in the company
Team playing
MANUFACTURING PROCESS OF
TURBO GENERATOR & STATOR BAR
BRIEF SUMMARY: ABOUT THE BAR SHOP
This shop is meant for manufacturing of stator winding coils of
generator that may be turbo generator or hydro generator.
HR BARS
Manufacturing of bars of different capacity depends upon
the water head available at site. The hydro generator is air
called generator of lesser length.
TURBO GENERATOR BAR
For the turbo generator the manufacturing of bars of
standard capacity such as 100 MW, 130MW, 150MW,
210/235MW, 210/250MW. This plant has capacity and
technology to manufacturing 800 MW generators.
TYPES OF GENERATORS
The generator may be classified based upon the cooling
system used in the generators such as;
THRI, TARI, THDI, THDD, THDF, THFF, THW
T =i.e. Turbo Generator or Hydro Generator.
H/A =i.e. Hydrogen Gas or Air.
R/D/F/I =i.e. Radial, indirect, forced, direct etc.
I/D/F =i.e. Indirect cooling, direct cooling, forced cooling.
W =i.e. cooling media used for cooling of stator coil e.g.
water.
MATERIAL CHECKING
First we check the material of the conductor. And the total
insulation upon the conductor. The width of the copper conductor
should be:
a. For Lower bar = 8 x 2.8mm (Solid)
b. For Upper bar = 8 x 1.3mm (Solid)
c. For Hollow conductor= 8 x 4.6 x 1.5mm (Solid)
CONDUCTOR CUTTING AND END CLEANING
This process is done by the automatic CNC machine, in this
process the length of lower bar & upper bar is decided as
following as per drawing-
Lower Bar
a. Solid conductor length = 10,200mm (10 Plates)
b. Hollow conductor length = 10,200mm (10 Plates)
Upper Bar
a. Solid conductor length = 10,050mm (10 Plates)
b. Hollow conductor length = 10,050mm (10 Plates)
This insulation is removed from both ends after the cutting of
conductor i.e. 500mm for both lower & upper bar.
TRANSPOSITION OF CONDUCTOR
Transposition means changing or shifting of position of each
conductor in active care (slot) part. After cutting the required
number of conductors are arranged on the comb in
staggered manner and than bands are given to the
conductor with the help of bending die at required distance.
Setting of die
a. Comb of setting for lower bar’s
Die 1st Die 2nd Die 3rd
2200.2mm 3735.3mm 6586.2mm
b. Comb of setting for Upper bar’s
Die 1st Die 2nd Die 3rd
2109mm 3620.2mm 6496.2mm
This process is repeated to making another half of the bar.
CROSS OVER INSULATION
Cross over insulation is give to the conductor for the protection in
which the insulating spacer are provided at the cross over portion. In
this insulation the No-max paper is used.
Here the filter material (insulating putty of moulding
micanite) spacer is provided along the high of bar to maintain
the rectangular shape. The size of spacer should be –
1st Band = 146mm
2nd Band = 219mm
3rd Band = 292mm
STACK CONSOLIDATION OR PRESSING
The core part of the bar stack is pressed in press under the
pressure between 70kg to 80kg (various from product to
product) and the temperature between 90 Deg.C to 160 Deg.C
for a given period. Here four bars is pressed in one time and
six to eight plates are used for pressing. After that the
consolidated stack is withdrawn from the press.
INTER STAND SHORT TEST (I.S.S.Test)
In this test first we make the distance to the non insulating
portion of the bar. Here we check the short between any two
conductor. After this test the bars are again go for the second
pressing. In which attached full slot separator between two
half bar no-max paper and tapped with transparent film. In this
test if any error is found then it has to be rectified.
FORMING OF BAR
In this operation the straight bar stack is formed as per
overhang profile. In this process bars should be formed on
universal former and marked for the thermal space. After it
they are moved for cutting of extra conductor.
ZERO PICKLING OF BAR END
Pickling is the process of the cleaning of components by the
chemicals. The pickling solutions are:
a. Water = 100 parts by weight
b. Sulphuric Acid = 10 parts by weight
c. Phosphoric Acid = 5 parts by weight
d. Hydrogen per Oxide = 5 parts by weight
The temperature should be maintain 50 Deg.C to 60 Deg.C.
The end portion of bar is dipping in this solution upto 10 to 15 min.
During this pickling process some aciditic properties are effected
to the end portion of bar. So to neutralization of it dipped the bars again
in the ammonia solution. For the shining of end part the bars are dipped
in ethyal alcohol (C2H5OH) solution and dry with nitrogen Pressure.
COIL LUG MOUNTING
In this process contact sleeve and the bottom part of the water box
are adjust at the give dimensions. The operation of mounting of
contact sleeve and bottom part of water box is complete in following
steps-
a. Check the dimension of contact sleeve and water box bottom part.
b. Stand by bar for setting of lug.
c. Setup to the solid conductor in each row as per drawing.
d. Then insert the contact sleeve upon the solid and hollow
conductor and temporally installed to it. And also installed the
bottom part of water box.
e. Maintain the gap between contact sleeve and bottom part of
water box approx 20mm.
After the lug mounting cutting of extra solid conductor.
MAIN BRAZING
There are the following steps to brazed the lug.
a. Stand by bar of setting for brazing.
b. Then heated the lug point through the two indictor at the
temperature of 700 Deg.C .
c. For brazing use brazing alloy L-Ag-15P by four person. This is the
silver platinum alloy wire of melting point 700 Deg.C to 750 Deg.C.
d. This Temperature is give through the laser rays.
CONDUCTOR CUTTING, FACE MILLING AND DEBBERING
After the main brazing bars is moved for cutting of extra part of
conductors as per drawing. Here cut the end part of the
bottom part of water box and taken for face milling.
In this process the conductor is given the accurate shaped as
per the measurement and it is taken in account that any part of
the surface is not left uneven and dull.
Then in Debbering, the bars edges are many a time left with
twigs and sharp needle type mettle cutting known as bar and
this process of removing is known as Debbering.
FIRST PICKLING
This is the same process of pickling which is done before the
lug mounting or zero pickling. After this pickling process the
bar is moved the brazing of top part of water box in both side.
BRAZING OF TOP PART
Thought the induction process the top part of water box is
brazed in both side.
As per the previous main brazing first we stand by bars of
setting for brazing then we attached the top part from the bottom
part of water box. Then healed the top part by top inductors at
the temperature of 400Deg.c.
For this type of brazing use L-Ag-40Cd. This is the alloy
silver academy which have 40% cadmium and the melting point
is 400 Deg.C to 500 Deg.C. This brazing is done for both end.
After the brazing the bars is go for second pickling which is the
same process as previously explain.
WATER FLOW TEST
Thought this test check the flow water equivalently in the hollow
conductor of the bar. There is the following steps of checking-
a. Water should be exit all the total hollow conductor.
b. If some burrs are jammed it should be removed to give very
high pressure of water and clean with the help of solid wire.
c. The main point of testing is that the water flow into the bar and
exit from the water box fall down approximately to cover 1 Mtr.
From each conductor.
NITROGEN LEAK TEST
In this test the bar is tested for leakage into the components of bar. In
this test flow of nitrogen gas with pressure of 10kg/Cm2 to
check the leakage in to the hollow conductor. If leakage found
the bar is rejected.
THERMAL SHOCK TEST
The cycles of hot (80 Deg.C) and cold (30 Deg.C) water are flew
thought the bar to ensure the thermal expansion and contraction
of the joints. The time of low of hot & cold water should be
approx 32 to 40min and give the time between to flow of hot &
cold water is 5 min. this process is applied atleast 8 hours.
HELIUM LEAKAGE TEST
In this test the bar’s end is tested to flow of helium gas with the
given pressure if the end part of the bar is leakage then the
helium gas is covered the surface of water box and indicator
indicate the point of leakage.
INSULATION
For the insulation sunmika therm tape or sunmika pleese tape is
used which is the combination of mica + glass + varnish. It is used
for corona protection. In this insulation to layer of pleese tape + to
layer of therm tape and after them again to mica pleese tape is used.
Process of Insulation
a. Clean the bar.
b. Clean with chemical or thinner.
c. Taping
d. Realizing film from the mica plastic section.
In insulation the wall thickness of insulation is subjected to the
generating voltage of the machine.
IMPREGNATION AND BAKING
1. Thermoreactive system: In case of rich resin insulation the bar
is pressed in closed box in heated condition and baked under
pressure and temperature as per requirement for a given period.
2. Micalastic system: In case of poor resin system the insulated
bars are heated under vaccum and impregnated (dipped) in
heated resin so that all the air gaps are filled, layer by layer
with resin then extra resin is drained out and bars are heated
and baked under pressed condition in closed box fixture.
VPI Micalastic System
The bars already laid in closed fixture and full fixture is
impregnated in resin and then fixture with box is baked under
given temperature for the given duration.
VIP Micalastic System
The individual bar is heated in vaccum and impregnated in
resin. Then bar is taken out and pressed in closed box fixture
and then baked at given temperature for given duration.
FINISHING
The baked and dimensionally correct bars are sanded-off to
smoothen the edges and surface calibrated if required for the
dimension.
CONDUCTING VARNISH COATING
OCP (Outer Corona Protection) Coating: The black semi-
conducting varnish coating is applied on the bar surface on the
core length.
ECP (End Corona Protection) Coating: The grey semi-conducting
varnish is applied at the bend outside core end of bars in gradient to
prevent from discharge and minimize the end corona.
TESTING
1. Tan Test: This test is carried out to ensure the healthiness of
dielectric (insulation) i.e. dense or rare and measured the
capacitance loss.
2. H.V. Test: The each bar is tested momentarily at high voltage
increased gradually to three times higher than rated voltage.
DISPATCHED FOR WINDING
If the bar is passed in all the operation and testing after
completing then the bar is send for stator winding.
TURBO GENERATORS
(a) Air Cooled Generators Upto 200 Mw Range (Type: TARI ) Salient Design Features
Stator core and rotor winding direct air-cooled
Indirect cooling of stator winding
Horizontally split casing design of
stator
Vertically side mounted coolers
in a separate housing
Micalastic bar type insulation system
Separately assembled stator core and
winding for reducing the manufacturing
cycle Brushless/static excitation system
(b) Hydrogen Cooled Turbogenerators Of 140-260 Mw Range (Type: THRI ) Salient Design Features
Stator core and rotor winding
directly hydrogen cooled
Indirect cooling of stator winding
Rigid core bar mounting
Micalastic insulation system
End shield mounted bearings
Top ripple springs in stator
slots Ring type shaft seals
Symmetrical ventilation.
MOTOR WINDING
9.1 Technical Requirements
(1) Count the coil groups in the anti clock wise direction locking
from the connection end.
(2) Leads of the coils groups lying on the outer periphery of the
overhang position shall be the finish and those lying on the inner
periphery shall be the start to coil groups.
(3) Leads shall be taken form the coil side lying at inner periphery
of slot No.1.
(4) The coil group No.1 shall Lie at top with its axes coinciding
with the vertical axis of the frame.
(5) Take out terminal leads 02 U2, V2, W2 for left hand side
terminal box and 02 U1, V1, W1 for right hand side terminal box.
When looking form the connection end.
Circuit diagram:-
WINDING DIAGRAM OF MOTOR WINDING
9.2 Winding data
NO. OF PHASE 3NO. OF POLES 6
PHASE CONNECTION YNO. OF PARELLEL PATH 2
NO. OF COIL GROUP 18
9.3 Connection of motor winding
CONCLUSION
The second phase of training has proved to be quite faithful.
It proved an opportunity for encounter with such huge machines like
turbo-generator hydro generator etc.
The architecture of B.H.E.L., the way various units are linked
and the way working of whole plant is controlled make the students
realize that Engineering is not just structural description but greater
part is planning and management. It provides an opportunity to
learn tech. Used at proper place and time can save a lot of labour.
But there are few factors that require special mention. Training
is not carried in true spirit. It is recommended that there should be
projectors especially for trainees where presence of authorities is ensured.
However, training has proved to be satisfactory. It has allowed
us an opportunity to get an exposure of the practical
implementation of theoretical fundamentals.