SOURCE OF ENERGY

THERMAL ENERGY

Thermal Energy

A. Temperature & Heat

1. Temperature is related to the average kinetic energy of the particles in a substance.

2. SI unit for temp. is the Kelvin

a. K = C + 273 (10C = 283K)

b. C = K – 273 (10K = -263C)

3. Thermal Energy is the total of all the kinetic and potential energy of all the particles in a substance.

Thermal energy relationships

a. As temperature increases, so does thermal energy (because the kinetic energy of the particles increased).

b. Even if the temperature doesn’t change, the thermal energy in a more massive substance is higher (because it is a total measure of energy).

Thermal energy is the portion of the thermodynamic or internal energy of a system that is responsible for the temperature of the system. The thermal energy of a system scales with its size and is therefore an extensive property. It is not a state function of the system unless the system has been constructed so that all changes in internal energy are due to changes in thermal energy, as a result of heat transfer (not work). Otherwise thermal energy is dependent on the way or method by which the system attained its temperature.

From a macroscopic thermodynamic description, the thermal energy of a system is given by its constant volume specific heat capacity C(T) , a temperature coefficient also called thermal capacity, at any given absolutE temperature (T):The heat capacity is a function of temperature itself, and is typically measured and specified for certain standard conditions and a specific amount of substance (molar heat capacity) or mass units (specific heat capacity).

For the Heat engine, Change in energy = heat added minus work

done

ΔU = Q – W

For the Colder region, Entropy = heat added divided by the

temperature ΔS = Q/T

Photo of thermal power plant inDahanu ,Maharashtra.

RELIANCE THERMAL STATION

• Ramagundam Thermal Plant in Andhra Pradesh, RaichurThermal Plant in Karnataka , Korba Thermal Plant in Madhya Pradesh , Farraka Thermal Plant in West Bengal are a few of the thermal power plants located in India.

• THERMAL POWER PLANTS ARE FOUND MOSTLY IN ALL THE STATES

2.The transmission of electricity is more efficient than transporting coal or petroleum over the same distance . Therefore , many thermal power plants are set up near coal or oil fields . In a thermal power plant , heat energy is converted into electrical energy.

3. The energy efficiency of a conventional thermal power station, considered salable energy produced as a percent of the heating value of the fuel consumed, is typically 33% to 48%. As with all heat engines, their efficiency is limited, and governed by the laws of thermodynamics. By comparison, most hydropower stations in the United States are about 90 percent efficient in converting the energy of falling water into electricity

Advantages of coal based

thermal Power Plant

• They can respond to rapidly changing loads without difficulty.

• A portion of the steam generated can be used as a process steam In different industries.

• Steam engines and turbines can work under 25 % of overload continuously

• Fuel used is cheaper.

• Cheaper in production cost in comparison with that of diesel power stations.

THE UPCOMING MAP SHOWS LOCATIONS OF THERMAL POWER PLANTS IN INDIA AND THE STATES/AREAS BENEFITED NEAR THEM.

there ARE FOUR MAIN CIRCUITS

1. Coal & Ash Circuit – This circuit deals mainly with feeding the boiler with coal for combustion purposes and taking care of the ash that is generated during the combustion process. It includes equipment and paraphernalia that is used to handle the transfer and storage of coal and ash.

Photo of thermal power plant .

Photo of thermal power plant.

1. Cooling tower 10. Steam Control valve 19. Superheater

2. Cooling water pump 11. High pressure steam turbine 20. Forced draught (draft) fan

3. transmission line (3-phase) 12. Deaerator 21. Reheater

4. Step-up transformer (3-phase) 13. Feedwater heater 22. Combustion air intake

5. Electrical generator (3-phase) 14. Coal conveyor 23. Economiser

6. Low pressure steam turbine 15. Coal hopper 24. Air preheater

7. Condensate pump 16. Coal pulverizer 25. Precipitator

8. Surface condenser 17. Boiler steam drum 26. Induced draught (draft) fan

9. Intermediate pressure steam turbine 18. Bottom ash hopper 27. Flue gas stack

• HEIGHT AND STRUCTURE

• OF

• THERMAL POWER PLANT

• Volume of concrete for shaft of boiler tower 1,200m3; Surface of coffering for shaft of boiler tower 8,300m2; Volume of concrete for tower belt 760m3; Surface of coffering for tower belt 950m3; Volume of reinforced concrete for chimney shaft 1,040m3; Surface of coffering of chimney shaft 8,300m2; Volume of concrete for foundations 660m3. The figures provided here would— in case of construction according to the invention—lead to a reduction in the cost of these comparative elements by 60%, compared to the cost of the conventional solution; this would hold true within the framework of the construction of a single boiler unit.

Thermal energy is essential in producing electricity, in industrial processes like oil refining, and in home heating, to think of just three applications. Disadvantages include producing greenhouse gases (except in nuclear heating).It pollutes the atmosphere due to production of large amount of smoke and fumes.

1.It uses non-renewable sources of energy such as coal.

2.It requires a large amount of water.

3.Handling of coal and disposal of ash is quite difficult.

ENVIORNMENTAL

PURPOSE

It would reduce thermal pollution if those using cooling water were to

empty the heated water into shallow ponds or canals, wait for it to cool and

then reuse the water; land availability is a hindrance to this method, but this is

the idea behind using cooling towers. A cooling tower is an efficient way to

reduce thermal pollution because it transfers the heat from the water into the

atmosphere. Cooling towers are wet or dry. The rejection of heat into a dry

tower is evaporative and raises the relative humidity. According to the Cooling

Technology Institute, the cooling potential of a wet surface is much better

because there is less evaporative heat transferred into the atmosphere.

Generation of electric power uses the largest percentage of cooling water, thus reducing the amount of electricity that is used will reduce thermal pollution. Although there is an increasing number of a power-generating plant, the amount of thermal pollution has not increased at the same rate because of improved efficiency of power plants and the increased use of hydropower. An increase in the use of nuclear power won't reduce the need for cooling waters since they also use cooling water.

Heated water can be cooled before releasing it, and less can be released

to cause less damage. Unfortunately, the cheapest and easiest way to

get cooling water is to withdraw it from a nearby body of water and

then release it back into the body of water heated. The warmer

temperature water lowers the oxygen content of the water, which

increases the respiratory rates of aquatic organisms and weakens them

so that they are more vulnerable to disease and death. Releasing the

heated water near the shoreline doesn't lessen the problem since this

may disrupt spawning and kill fish.

TO IMPROVE THE EFFICIENCY OF THERMAL POWER PLANT

• Using the heat of flew gases(Economiser & Air preheated) • Increasing efficiency of Generator. • Using the dry coal . • convert some of the condenser wasted energy to electricity using thermoelectric material.