report on steam turbines

1. BHARAT HEAVY ELECTRICALS LIMITED
Industrial Training Report

2. OVERVIEW OF BHEL:
● BHEL was establishedin 1964.
● BHEL is one of the only 7 Public Sector Undertakings
(PSUs) of Indiaclubbed under the esteemed
'Maharatna'BHEL was establishedin 1964.
● BHEL is one of the only 7 Public status. On 1st February
2013, the Government of India granted Maharatna status
to BHEL.
● BHEL has a share of 59% in India’stotal installed
generating capacitycontributing 69% (approx.) to the total
power generated from utilitysets (excluding non-
conventionalcapacity)as of March 31, 2012.
● BHEL is engaged in the design, engineering, manufacture,
construction, testing, commissioning and servicing of a
wide range of products and services for the core sectors of
the economy, viz. Power, Transmission, Industry,
Transportation(Railway) RenewableEnergy, Oil & Gas and
defence.
● BHEL has 15 manufacturing divisions,two repairunits, four
regional offices, eight service centers and 15 regional

3. centers and currently operate at more than 150 project
sites across Indiaand abroad.
Main Manufacturing Units:
1. BHEL Bhopal (MadhyaPradesh )
2. BHEL Ramachandrapuram,Hyderabad(Andhra Pradesh)
3. Transformer Plant, BHEL Jhansi(UttarPradesh)
4. High Pressure Boiler Plant and Seamless Steel Tube Plant,
Tiruchirapalli(TamilNadu)
5. Boiler Auxiliaries Plant, Ranipet(Tamil Nadu)
6. ElectronicsDivisionandElectro Porcelain Division,
Bangalore(Karnataka
7. Jagdishpur(Uttar Pradesh)
8. Rudrapur(Uttrakhand)
9. Industrial ValvesPlant,Goindwal(Punjab)
10. BHEL Ranipur, Haridwar(Uttarakhand)
11. Bharat Heavy Plates and Vessels Limited(Vizag)

4. BHEL RAMACHANDRAPURAM UNIT
● BHEL RamachandrapuramUnit has acquiredconsiderable
experience in the design and manufacture of various
important types of pumps required for the thermal power
plants
● Designed and manufactured for 60 MW, 110 MW and 210
MW under technicalcollaborationwith M/s. Sigma Lutin
of Czechoslovakia.
● In order to meet the requirements of higher efficiency
pumps for 210 MW units and large capacitypumps for 500
MW units, collaboration wasentered in 1980 with M/s.
Wier Pumps Limited, U.K., who are acknowledged as one
of the leading manufacturers of pumps in the world.
● In 2007, BHEL Hyderabad has entered into collaboration
with M/s. Mitsubishi Heavy Industries, Japanto
manufacture pumps for super-critical thermal power
plantsup to 1000 MW.

5. PRODUCT AND PROCESSES:
● Turbine & Compressors shop.
● Steam Turbines Compressors.
● Gas Turbines Compressors.
● Turbo Generators.
● Steam Generators.
● Gas Generators.
● Switch Gears.
● Ferrous Foundry.
● Non-Ferrous Foundry.
● Heat Exchangers.
● Tool Room.
● Heat Treatment.
● Pattern shop.
● Spares Manufacturing.
● Coal pulverizes.
● Pumps.

6. Steam turbines manufactured:
Varioustypes of SIEMENS model turbines are manufactured at
BHEL – Hyderabadaccording to the requirement of any
customer to suit his boiler steam parameters. They are :-
Type of turbines:
● G - Back pressure type.
● EG - Extraction back pressure type.
● EHG - Extraction back pressure type with high inlet
parameters.
● HG - Back pressure type with high inlet parameters.
● K - Condensingtype.
● EK - Extraction condensing type.
● WK - Double flow condensing type.
● EMG - Electrochemicallymachinedrotor of back pressure
type.
● EHNK - Extraction condensing with inlet parameters and
high speed type.
● NK - Straight condensing with high speed type.
Categories in steam turbine:

7. Industrial steam turbine are categorized into different series
like :-
● 2 series
● 3 series
● 4 series
2 SERIES TURBINES:
● Standard type and have been designed for the best
efficiency for range parameters.
● Designs being the standard further based on then steam
flow quantitiessize of the turbine is selected.
● In these series of turbines the fixed bladegrooves are
machined directly in the outer casing and guide blades are
inserted.

9. Different sizes of -2 types of turbines
are:
● G250-2 EK/K 600-2
● G300-2 EK/K 800-2 .
● G400-2 EK/K 1000-2 .
● G500-2 EK/K 1100-2 .
● G800-2 EK/K 1400-2 .
● “G” stands for back pressure turbine.
● “K” stands for condensing turbines.
● “E” stands for controlled extraction.
● 3 SERIES TURBINE.
3 SERIES TURBINE:
● Based on customer‟s requirements and steps involvedin
design, the turbine is dividedinto different sections: inlet
section, transition,exhaust or condensing section.
● The size of the section is geometrically graded in the ratio
to 1.25 to form different sizes of section.

11. 4 SERIES TURBINES:
● These types of series are called as centre admission steam
turbines with counter flow.
● range of power, between 30MW to 150 MW.
● The steam reverses the direction on the reaching the end
of inner casing to flow around inner casing and expands
towards the rear end of the turbine.
● This process of reverse flow of steam helps in control the
axial thrust to a large extent.
● These turbines are directly coupled to the generator. The
valve blocks in these turbines are separate.

13. MACHINE SHOPS:
● BAY 0
Maintenanceand service dept / Heavy duty CNC
machines / Steam turbine 150 MW Assembly shop
Bay 1
Heavy duty CNC machines / Gas turbine rotor
Assembly.
● Bay2
Heavy machine shop withHeavy duty CNC and
conventionalmachines.
● Bay 3
Blade shop
● Bay 4
Heavy duty CNC Lathe machines and steam turbine
rotor assembly.

14. ● Bay 5
Impeller shop / Light machine shop / Gas turbine wheel
Assembly.
● Bay 6
Medium machineshop.
● Bay 7
Gas turbine machine shop / Steam turbine Regulation
Assembly.

15. CNC horizontal boring machines 2
nos

16. Tacchi CNC lathes 2 nos

17. INNSE Horizontal CNC machine :

18. Mario Carnaghi Gantry type machine :
● Rough machiningof heavy casings of 120 MW design is
carried out on this machine. Both top and bottom casings
● can be placedside by side on the table with the parting
plane up for machining.
Gas turbine Rotor Balancing machine :
● The rotors are balancedindividuallyand as a unit rotor
also for its unbalancebefore lowering into the gas Gas
turbine Rotor Balancing machine :

19. ● Machiningof heavy rotors, drilling, reaming of Coupling
holes on turbine rotor and loadcoupling of gas turbine
also carried out in this shop
Tacchi heavy duty CNC lathe:
● Machiningof heavy duty rotors are carried out on this
machine. The max weight carrying capacity of the machine
is 80 T. This machine is provided with Sinumerik 840 D CNC
system.

20. ● Gas turbines of Fr5, Fr6 and Fr9 flange to flange assembly
is carried out here.
Bay 2
Heavy machine shop withHeavy duty CNC and conventional
machines
● With Heavy duty CNC and conventional machinesHeavy
machine shop.

21. ● Machiningof peripheral detailsand grinding of parting
planes of casings are carried put in this shop. The
important machines in this bay are Plano grinding machine
etc Radialdrillingmachines etc.
● Heavy duty CNC machines.
● MitsubishiHorizontal boring machine.
● DorriesVeritical CNC lathe.
● Skoda Horizontal boring machine.
● Skoda Vertical CNC lathe.
Mitsubishi Horizontal Boring
Machine :
● Fir tree blade root machiningon steam turbine rotor is
carried out on this machine.
● Fanuc 9 CNC system.

22. Skoda Vertical CNC lathe:
● Finishing machiningcasings includingguide bladegrooves
are carried out in vertical positionon this lathe. The
machine is provided with 840-C CNC system.

23. Bay 4
Heavy duty CNC Lathe machines and
steam turbine rotor assembly
● Steam Turbine rotor Assembly.
● Sealing fins drawing machine.
● LP drillingMachine .
● A-Wheel drillingMachine (Impulse bladedrilling machine).

24. CASING SHELL OR CYLINDER
Casing Materials
● ASTM A 356 Grade 1 for cast carbon steel.
● NodularCast Iron GGG40.
● The reason is that cast carbon steel is weld repairable(LP
turbine inner casing rings,).
● 1-2 cr mo steels –low temperature steam.
● Cast 9 Cr 1 –Mo- V –Nb alloys.
● 9-12-cr martensite /ferrite steel.

25. Properties :
● Applicationsas they offer useful.
● Combinationof high temperature mechanical.
● Properties and corrosion/oxidationresistance.
Casing bolts:
Bolting materials
● Nimonic 80A.
● Inconel 740.
● Allvac 718 plus (super alloy).
Properties:
● High resistance to stress relaxation.
● Creep relaxation behaviour.
● Offering excellent mechanical properties.
● Increased temperature capability, good fabricability and
moderate costUnstable states arising during start-ups,
shutdowns and load changes give rise to unsteady
temperature distribution with time in steam turbine
innercasing(HP/IP), which results in non-uniform strain
and stress distribution.

26. ● The rapid increase of temperature during starts-ups,
especially, causes susceptible to failure and reduction of
expected life for steam turbine components. Thus
accurate knowledge of thermal stressesis required for
the integrity and lifetime assessmentfor the turbine.
MACHINING SEQUENCE
UNDERGONE BY STEAM TURBINE
CASING:
● Marking on both lower half and upper half of casing with
machine allowance.
Or
● Punching on cnc machine during machining with
allowances.
● Skin cut on connecting flang face of lower half by
positioningthe parting plane downwards this process is
repeated for upper half also.
● Now the loadingthe lower half in vertical positionby the
help of bearing and clamps.
● Repeat the process for upper half as well.

27. ● Parting plane present in both upper half and lower half are
rough milled and then are followed by finish millingby
positioningthe job in vertically with inner part facing the
milling cutter (INNSE).
CONCLUSION:
Finally by this industrial training from BHEL we have studied
about the manufacturing and assembly of steam and gas
turbines.