thermal and nuclear power plant

A nuclear power plant or nuclear power station is a thermal power station in which the heat source is a nuclear reactor. As is typical in all conventional thermal power stations the heat is used to generate steam which drives a steam turbine connected to an electric generator which produces electricity.
A thermal power station is a power station in which heat energy is converted to electric power. In most of the places in the world the turbine is steam-driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator.

1. THERMAL POWER PLANT A  thermal power station  is a power station in which heat energy is converted to electric power. In most of the places in the world the turbine is steam-driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was heated; this is known as a  Rankine cycle.

2. CON T ENTS INTRODUCTION WORKING PRINCIPLE GENERAL LAYOUT OF THERMAL POWER PLANT MAIN EQUIPMENTS WASTE GENERATED AND THEIR CONTROL ADVANTAGES AND DISADVANTAGES REFERENCES

3. INTRO D UCTION A Thermal Power Plant converts the heat energy of coal into electrical energy. Coal is burnt in a boiler which converts water into steam. The expansion of steam in turbine produces mechanical power which drives the alternator coupled to the turbine.Thermal Power Plants contribute maximum to the generation of Power for any country. Thermal Power Plants constitute 75.43% of the total installed captive and non-captive power generation in India. In thermal generating stations coal, oil, natural gas etc. are employed as primary sources of energy.

4. WORKING PRINCIPLE Firstly the water is taken into the boiler from a water source. The boiler is heated with the help of coal. The increase in temperature helps in the transformation of water into steam. The steam generated in the boiler is sent through a steam turbine. The turbine has blades that rotate when high velocity steam flows across them. This rotation of turbine blades is used to generate electricity. A generator is connected to the steam turbine. When the turbine turns, electricity is generated and given as output by the generator, which is then supplied to the consumers through high-voltage power lines.

5. GENERAL LAYOUT OF THERMAL POWER PLANT

6. MAIN EQUIPMENTS Coal handling plant Pulverizing plant Boiler Turbine Condenser Cooling towers and ponds Feed water heater Economizer Air preheater

7. COAL HANDLING PLANT Coal is transported to power station by rail or road and stored in coal storage plant and then pulverized. The f u ncti o n o f coal handling p l ant is aut o m atic feeding of coal to the boiler furnace. A thermal power plant burns enormous amounts of coal. A 200MW plant may require around 2000 tons of coal daily.

8. PULVERIZING PLANT In m o d ern t h er m al p ower p l ant, coal is p u l v eriz e d i. e . ground to dust like size and carried to the furnace in a stream of hot air. Pulverizing is a means of exposing a large surface area to the action of oxygen and consequently helping combustion. Pulverizing process consists 3 stages classified as: Feeding Drying Grinding

9. BOILER The function of boiler is to generate steam at desired pressure and temperature by transferring heat produced by burning of fuel in a furnace to change water into steam. TURBINE In thermal power plants generally 3 turbines are used to increases the efficiency. High pressure turbine Intermediate pressure turbine Low pressure turbine

10. CONDENSER The surface condenser is a shell and tube heat exchanger where cooling water flows through tubes and exhaust steam fed into the shell surrounds the tubes. as a result, steam condense outside the tubes.

11. A condenser needs huge quantity of water to condense the steam. Most plants use cooled cooling system where warm water coming from condenser is cooled and reused. Cooling tower is a steel or concrete hyperbolic structure with the height of 150m. COOLING TOWERS AND PONDS

12. FEED WATER HEATER Feed water heating improves overall plant efficiency. Thermal stresses due to cold water entering the boiler drum are avoided. Quality of steam produced by the boiler is increased.

13. ECO N OMIZER Flue gases coming out of the boiler carry lot of heat. An economizer extracts a part of this heat from flue gases and uses it for heating feed water. Saving coal consumption and higher boiler efficiency.

14. AIR PREHEATER The function of air preheaters is to preheat the air before entering to the furnace by utilizing some of the energy left in the flue gases before exhausting them to the atmosphere. After flue gases leave economizer, some further heat can be extracted from them and used to heat incoming heat. Cooling of flue gases by 20 degree centigrade increases the plant efficiency by 1%.

15. WASTE GENERATED AND THEIR CONTROL ASH HANDLING PLANT WATER HANDLING PLANT

16. NUCLEAR POWER PLANT A  nuclear power plant  or  nuclear power station  is a thermal power station in which the heat source is a nuclear reactor. As is typical in all conventional thermal power stations the heat is used to generate steam which drives a steam turbine connected to an electric generator which produces electricity. As of 23 April 2014, the IAEA report there are 449 nuclear power reactors in operation operating in 31 countries .

17. Electricity was generated for the first time ever by a nuclear reactor on December 20, 1951 at the EBR-I experimental station near Arco, Idaho in the United States. On June 27, 1954, the world's first nuclear power plant to generate electricity for a power grid started operations at Obninsk, USSR. The world's first commercial scale power station, Calder Hall in England opened in October 17, 1956.

18.  A chain reaction refers to a process in which neutrons released in fission produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats. If the process is controlled it is used for nuclear power or if uncontrolled it is used for nuclear weapons

19. A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical Various high-performance alloys and super alloys have been used for steam generator tubing.

20. Nuclear power generation does emit relatively low amounts of carbon dioxide (CO ₂ ). The emissions of green house gases and therefore the contribution of nuclear power plants to global warming is therefore relatively little. This technology is readily available, it does not have to be developed first. It is possible to generate a high amount of electrical energy in one single plant

21. Nuclear power plants as well as nuclear waste could be preferred targets for terrorist attacks. During the operation of nuclear power plants, radioactive waste is produced, which in turn can be used for the production of nuclear weapons

22. Nuclear power is the fourth-largest source of electricity in India after thermal, hydroele ctric and renewable sources of electricity. As of 2010, India has 20 nuclear reactors in operation in six nuclear power plants, generating 4,780 MW while five other plants are under construction and are expected to generate an additional 2,720 MW.