13-10-2012, 01:17 PM
INDUSTRIAL TRAINING AT BHEL, HARIDWAR
INDUSTRIAL TRAINING.ppt (Size: 187.5 KB / Downloads: 141)
BHARAT HEAVY ELECRTICALS LIMITED
BHEL is one of NAVRATANAS among NTPC, VSNL, ONGC, IOC, HPCL, SAIL, IPCL, BPCL & BHEL
Featured in “FORTUNES INTERNATIONALS 500” among 12 top companies in world for manufacturing of variety of mechanical & electrical equipment for generation, transmission and electricity
ISO 9000 certified for quality management, and ISO 14001 certified for environment management
BHEL caters to power generation and transmission industry, transportation, telecommunication, renewable energy, defence etc.
First plant was established in Bhopal in 1964; in Haridwar in January,1967
Today BHEL has 14 manufacturing divisions, 9 service centers, 4 power sector regional centre and about 150 project sites
STEAM TURBINE
A steam turbine is a prime mover in which rotary motion is obtained by gradual change of momentum of steam
Modes of operation of steam turbine
Impulse principle
Reaction principle
Stages of steam turbine
H P ( High Pressure)
I P ( Intermediate Pressure)
L P ( Low Pressure)
MATERIAL
Parameters of material selection
Hot yield (0.2% yield stress)
Creep and rupture
Relaxation properties
Cyclic loading behaviour
Fatigue failure
Fracture toughness
Rate of crack growth
Resistance to scaling
Material used currently
13% Cr. Stainless Steel Bars
(C = 0.22%, Si = 0.5%, Mn = 0.8%, Cr = 13%, Ni = 0.8%, S = 0.020%,
P = 0.030%)
VALVES
HP turbine is fitted with two initial steam stop and control valves
IP turbine has two stop and control valves
Stop valve is used to immediately stop the supply of steam (emergency valve)
Control valve is used to control the steam flow rate by means of governor
These valves are arranged at right angles to each other in a common body
These valves are actuated by oil hydraulic mechanisms
GOVERNING SYSTEM
The turbine has an electro-hydraulic governing system
The governing system permits run up control of the turbine up to the rated speed and keep speed swings due to variation in load
The electric system measures the variation in speed and output by means of sensors and send signals to electro-hydraulic converter.
The electro hydraulic converter then operates servomotor by hydraulic means to control steam flow rate