09-04-2011, 12:13 PM
presented by:
VINOD KUMAR BHARTI
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INTRODUCTION
NATIONAL THERMAL POWER CORPORATION
ESTABLISHED 7th NOVEMEBER 1975
GOVT. SHARE 89.5%
NTPC CONTRIBUTES MORE THAN 35% OF INDIA’S POWER NEEDS
TOTAL POWER PRODUCTION:27,904MW
15 COAL BASED(22,895MW) & 7 GAS BASED(3,955MW) & FOUR OTHER JOINT VENTURES
“Centre for Power Efficiency and Environment Protection (CENPEEP)” has been established in NTPC with the assistance of United States Agency for International Development (USAID)
As a responsible corporate citizen, NTPC is making constant efforts to improve the socio-economic status of the people affected by its projects
THEMAL POWER PLANT
ELECTRICITY GENERATION PROCESS
o Thermal power station burns fuel and uses the resultant heat to raise steam which drives the TURBO GENERATOR.
o The fuel may be ‘fossil’(coal,oil,natural gas) or it may be fissionable, whichever fuel is used, the objective is same to convert the mechanical energy into electricity by rotating a magnet inside a set of winding.(according to faraday’s laws)
TURBOMACHINERY
MAIN PARTS OF POWER PLANT TURBOMACHINERY:
HP, IP, LP - TURBINES
TURBINE GOVERNING SYSTEM
TURBINE MONITORING SYSTEM
OIL SUPPLY SYSTEM AND CONTROL FLUID SYSTEM
HP,IP AND LP TURBINES:-
• Turbines works on reaction of condensation type with throttle governing and regenerative system of feed water heating.
• The Turbine is a single shaft machine with separate HP, IP, and LP Turbines.
• HP-turbine is a single flow cylinder
• IP and LP are double flow cylinders
• The individual turbine rotors and the Generator rotor are connected by rigid couplings.
TURBINE GOVERNING SYSTEM
• The turbine has an electro-hydraulic governing system.
• An electric system measures and controls speed and output, and output, and operates the control valves hydraulically in conjunction with an electro-hydraulic converter.
TURBINE MONITORING SYSTEM
IT RECORDS THE FOLLOWING DATA:-
• Absolute expansion, measured at the iron-T and rear bearing pedestal of the HP turbine
• Differential expansion between the shaft and turbine casing, measured at several points Bearing pedestal vibrations, measured at all turbine bearings.
• Relative shaft vibration (bearing pedestal shaft) measured at all turbine bearings.
• Absolute shaft vibrations, obtained from bearing pedestal vibration and relative shaft vibration by calculation.
OIL SUPPLY AND CONTROL SYSTEM
• An oil supply system lubricates and cools the bearings and drives the hydraulic turning gear.
• The Lubricating and Cooling oil is passed through oil coolers before being supplied to the bearings.
CONTROL & AUTOMATION
• THE BENEFITS
• The main benefits of plant automation are to increase overall plant availability and efficiency.
• Optimization of house load consumption during plant start- up, shut-down and operation, via:
• Faster plant start-up through elimination of control errors creating delays
• Faster sequence of control actions compared to manual ones.
– The sequence of a rapid restart using automation for a typical coal-fired
station. Even a well- trained operator crew would probably not be able to
bring the plant to full load in the same time without considerable risks.
MONITORING BEFORE & AFTER
PARAMETERS TO BE MONITORED
• Speed
• Temperature
• Current
• Voltage
• Pressure
• Flow of Gases
• Vacuum Pressure
• Valves
• Vibration
TEMPERATURE MONITORING
• We can use Thermocouples or RTDs for temperature monitoring
• Normally RTDs are used for low temperatures.
Thermocouple selection depends upon two factors:
• Temperature Range
• Accuracy required
• Normally used Thermocouple is K Type Thermocouple:
Chromel (Nickel-Chromium Alloy) / Alumel (Nickel- Aluminium Alloy)
• −200 °C to +1200 °C range. Sensitivity is approximately 41 µV/°C.
VIBRATION MONITORING
• The cause of Vibrations: A natural, free vibration is a manifestation of the oscillatory behavior in mechanical systems, resulting from the repetitive interchange of kinetic and potential energies among the components in the system.
Need of VMS(Vibration Monitoring system):
• Machine failure is expensive
• Rapid defect deterioration
• Machine is critical to production
• Variable speed/load machines
• Cost of machine is significant
• Poor accessibility during machine operation
CONTROL VALVES
• A valve is a device that regulates the flow of substances (either gases, fluidized solids,
slurries, or liquids) by opening, closing, or partially obstructing various passage ways.
• Pneumatic Valves – they are air or gas controlled which is compressed to turn or move them
• Hydraulic valves – they utilize oil in place of Air as oil has better compression
• Motorized valves – these valves are controlled by electric motors
CONCLUSION:
• UNDERGOING THE INDUSTRIAL TRAINING ON CONTROL & INSTRUMENTATION HERE I CAME TO KNOW THAT USING THE NEW INSTRUMENTATION TECHNIQUES USING ELECTRONICS & NETWORKING, THE CONTROLLING HAS BEEN MADE EASIER & NEEDS LESSER RESOURCES AS COMPARED TO THAT WERE USED IN PAST. SO ITS ADVANTAGEOUS THAN THAT WAS IN PAST.
• NEW POWER PLANTS ARE USING MAX-DNA TECHNOLOGY PRODUCED BY METSO AUTOMATION LMTD.