BHARAT HEAVY ELECTRICALS LIMITED

Industrial Training Report

OVERVIEW OF BHEL:

● BHEL was established in 1964.

● BHEL is one of the only 7 Public Sector Undertakings

(PSUs) of India clubbed under the esteemed

'Maharatna' BHEL was established in 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’s total installed

generating capacity contributing 69% (approx.) to the total

power generated from utility sets (excluding non-

conventional capacity) 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) Renewable Energy, Oil & Gas and

defence.

● BHEL has 15 manufacturing divisions, two repair units, four

regional offices, eight service centers and 15 regional

centers and currently operate at more than 150 project

sites across India and abroad.

Main Manufacturing Units:

1. BHEL Bhopal (Madhya Pradesh )

2. BHEL Ramachandrapuram, Hyderabad (Andhra Pradesh)

3. Transformer Plant, BHEL Jhansi(Uttar Pradesh)

4. High Pressure Boiler Plant and Seamless Steel Tube Plant,

Tiruchirapalli(Tamil Nadu)

5. Boiler Auxiliaries Plant, Ranipet (Tamil Nadu)

6. ElectronicsDivision and Electro 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)

BHEL RAMACHANDRAPURAM UNIT

● BHEL Ramachandrapuram Unit has acquired considerable

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 technical collaboration with M/s. Sigma Lutin

of Czechoslovakia.

● In order to meet the requirements of higher efficiency

pumps for 210 MW units and large capacity pumps for 500

MW units, collaboration was entered 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, Japan to

manufacture pumps for super-critical thermal power

plants up to 1000 MW.

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.

Steam turbines manufactured:

Various types of SIEMENS model turbines are manufactured at

BHEL – Hyderabad according 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 - Condensing type.

● EK - Extraction condensing type.

● WK - Double flow condensing type.

● EMG - Electrochemically machined rotor 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:

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 quantities size of the turbine is selected.

● In these series of turbines the fixed blade grooves are

machined directly in the outer casing and guide blades are

inserted.

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 involved in

design, the turbine is divided into 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.

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.

MACHINE SHOPS:

● BAY 0

Maintenance and 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

conventional machines.

● Bay 3

Blade shop

● Bay 4

Heavy duty CNC Lathe machines and steam turbine

rotor assembly.

● Bay 5

Impeller shop / Light machine shop / Gas turbine wheel

Assembly.

● Bay 6

Medium machine shop.

● Bay 7

Gas turbine machine shop / Steam turbine Regulation

Assembly.

CNC horizontal boring machines 2

nos

Tacchi CNC lathes 2 nos

INNSE Horizontal CNC machine :

Mario Carnaghi Gantry type machine :

● Rough machining of heavy casings of 120 MW design is

carried out on this machine. Both top and bottom casings

● can be placed side by side on the table with the parting

plane up for machining.

Gas turbine Rotor Balancing machine :

● The rotors are balanced individually and as a unit rotor

also for its unbalance before lowering into the gas Gas

turbine Rotor Balancing machine :

● Machining of heavy rotors, drilling, reaming of Coupling

holes on turbine rotor and load coupling of gas turbine

also carried out in this shop

Tacchi heavy duty CNC lathe:

● Machining of 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.

● 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.

● Machining of peripheral details and grinding of parting

planes of casings are carried put in this shop. The

important machines in this bay are Plano grinding machine

etc Radial drilling machines etc.

● Heavy duty CNC machines.

● Mitsubishi Horizontal boring machine.

● DorriesVeritical CNC lathe.

● Skoda Horizontal boring machine.

● Skoda Vertical CNC lathe.

Mitsubishi Horizontal Boring

Machine :

● Fir tree blade root machining on steam turbine rotor is

carried out on this machine.

● Fanuc 9 CNC system.

Skoda Vertical CNC lathe:

● Finishing machining casings including guide blade grooves

are carried out in vertical position on this lathe. The

machine is provided with 840-C CNC system.

Bay 4

Heavy duty CNC Lathe machines and

steam turbine rotor assembly

● Steam Turbine rotor Assembly.

● Sealing fins drawing machine.

● LP drilling Machine .

● A-Wheel drilling Machine (Impulse blade drilling machine).

CASING SHELL OR CYLINDER

Casing Materials

● ASTM A 356 Grade 1 for cast carbon steel.

● Nodular Cast 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.

Properties :

● Applications as they offer useful.

● Combination of high temperature mechanical.

● Properties and corrosion/oxidation resistance.

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.

● 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 stresses is required for

the integrity and lifetime assessment for 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

positioning the parting plane downwards this process is

repeated for upper half also.

● Now the loading the lower half in vertical position by the

help of bearing and clamps.

● Repeat the process for upper half as well.

● Parting plane present in both upper half and lower half are

rough milled and then are followed by finish milling by

positioning the 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.