01-07-2010, 01:18 PM
Introduction
Almost all coal, nuclear, geothermal, solar thermal electric, and waste incineration plants, as well as many natural gas power plants are thermal.
Natural gas is frequently combusted in gas turbines as well as boilers.
In thermal power stations, mechanical power is produced by a heat engine that transforms thermal energy, often from combustion of a fuel, into rotational energy.
HISTORY
Reciprocating steam engines have been used for mechanical power sources since the 18th Century
James Watt invented first steam engine.
The very first commercial central electrical generating stations in New York and London, in 1882, also used reciprocating steam engines.
As generator sizes increased, eventually turbines took over they encres the hose power.
Classification
¢ By fuel
¢ Nuclear power plants
¢ Solar thermal
¢ Fossil fuelled power plants
¢ By prime mover
¢ Steam turbine
¢ Gas turbine
¢ Reciprocating engines
Efficiency
The electric efficiency of a conventional thermal power station, considered as saleable energy (in MWe) produced at the plant busbars as a percent of the heating value of the fuel consumed, is typically 33% to 48% efficient.
Since the efficiency of the plant is fundamentally limited by the ratio of the absolute temperatures of the steam at turbine input and output, efficiency improvements require use of higher temperature, and therefore higher pressure, steam requried.
Basic definitions
Steam is vaporized water and can be produced at 100â„¢C at standard atmosphere.
In common speech, steam most often refers to the visible white mist that condenses above boiling water as the hot vapor mixes with the cooler air.
Turbine A turbine is a rotary engine that extracts energy from a fluid or air flow and converts it into useful work.
The second law of thermodynamics an expression of the universal principle of entropy, stating that the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium; and that the entropy change dSof a system undergoing any infinitesimal reversible process is given by dq / T, where dq is the heat supplied to the system andT is the absolute temperature of the system.
Advantages
¢ The fuel used is quite cheap.
¢ Less initial cost as compared to other generating plants.
¢ It can be installed at any place irrespective of the existence of coal.
¢ It require less space as compared to Hydro power plants.
¢ Cost of generation is less than that of diesel power plants.
¢ Can be loaded quickly
Disadvantages
¢ It pollutes the atmosphere due to production of large amount of smoke and fumes.
¢ It is costlier in running cost as compared to Hydro electric plants.
¢ The plant efficiency falls rapidly at part load
¢ A large number of circuits makes the design complex
¢ It occupies more space
¢ Ash disposal is a big problem
Future Prospects
Effective Use of Fossil Fuels and Reduction in CO2 Emissions by Improving the Efficiency of Thermal Power Generation
Accelerating the Development of CO2 Capture and Storage Technology
The Key to Realizing Next-generation Power Generation System
Effective Use of Fossil Fuels and Reduction in CO2 Emissions by Improving the Efficiency of Thermal Power Generation
Accelerating the Development of CO2 Capture and Storage Technology The Key to Realizing Next-generation Power Generation System
Almost all coal, nuclear, geothermal, solar thermal electric, and waste incineration plants, as well as many natural gas power plants are thermal.
Natural gas is frequently combusted in gas turbines as well as boilers.
In thermal power stations, mechanical power is produced by a heat engine that transforms thermal energy, often from combustion of a fuel, into rotational energy.
HISTORY
Reciprocating steam engines have been used for mechanical power sources since the 18th Century
James Watt invented first steam engine.
The very first commercial central electrical generating stations in New York and London, in 1882, also used reciprocating steam engines.
As generator sizes increased, eventually turbines took over they encres the hose power.
Classification
¢ By fuel
¢ Nuclear power plants
¢ Solar thermal
¢ Fossil fuelled power plants
¢ By prime mover
¢ Steam turbine
¢ Gas turbine
¢ Reciprocating engines
Efficiency
The electric efficiency of a conventional thermal power station, considered as saleable energy (in MWe) produced at the plant busbars as a percent of the heating value of the fuel consumed, is typically 33% to 48% efficient.
Since the efficiency of the plant is fundamentally limited by the ratio of the absolute temperatures of the steam at turbine input and output, efficiency improvements require use of higher temperature, and therefore higher pressure, steam requried.
Basic definitions
Steam is vaporized water and can be produced at 100â„¢C at standard atmosphere.
In common speech, steam most often refers to the visible white mist that condenses above boiling water as the hot vapor mixes with the cooler air.
Turbine A turbine is a rotary engine that extracts energy from a fluid or air flow and converts it into useful work.
The second law of thermodynamics an expression of the universal principle of entropy, stating that the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium; and that the entropy change dSof a system undergoing any infinitesimal reversible process is given by dq / T, where dq is the heat supplied to the system andT is the absolute temperature of the system.
Advantages
¢ The fuel used is quite cheap.
¢ Less initial cost as compared to other generating plants.
¢ It can be installed at any place irrespective of the existence of coal.
¢ It require less space as compared to Hydro power plants.
¢ Cost of generation is less than that of diesel power plants.
¢ Can be loaded quickly
Disadvantages
¢ It pollutes the atmosphere due to production of large amount of smoke and fumes.
¢ It is costlier in running cost as compared to Hydro electric plants.
¢ The plant efficiency falls rapidly at part load
¢ A large number of circuits makes the design complex
¢ It occupies more space
¢ Ash disposal is a big problem
Future Prospects
Effective Use of Fossil Fuels and Reduction in CO2 Emissions by Improving the Efficiency of Thermal Power Generation
Accelerating the Development of CO2 Capture and Storage Technology
The Key to Realizing Next-generation Power Generation System
Effective Use of Fossil Fuels and Reduction in CO2 Emissions by Improving the Efficiency of Thermal Power Generation
Accelerating the Development of CO2 Capture and Storage Technology The Key to Realizing Next-generation Power Generation System
