PowerPoint Presentation

Thermal Power Plants (Steam Power Plants)By P.SELVAMP.SATHISHP.SIVA VINOTH

MECHANICAL-BLecture OutlinesThermal EnergyEnergy conversion processPrinciple and WorkingEfficiencyMerits & DemeritsParts of steam power plant

Thermal Energy1. The kinetic energy of the molecules in a solid, liquid or gas2. The more kinetic energy, the more thermal energy the object possesses3. Physicists also call this the internal energy of an object

Energy Conversion . . . Fuel, Air and water produce steam in the boiler by combustionSteam of high temperature and pressure is expended from high pressure to low pressure in the turbineThermal energy is converted into kinetic energy and finally mechanical energyThis mechanical energy derives the generator to produce electricityEnergy Conversion Process in Steam Power PlantsChemical Energy isConverted into ThermalEnergy by Combustion In BoilerThermal Energy isConverted intoMechanical EnergyIn TurbineMechanical Energy isConverted into Electrical Energy In GeneratorChemicalEnergyFuelThermalEnergyMechanicalEnergyElectricalEnergySteam Power PlantsElectricity generation in thermal power plants if characterized by the main source of generation being firing of coal, gas etc. Steam is produced in a boiler, and it drives a turbine connected to an alternator. Heat energy is converted to electric energy within the so-called steam cycle.

THERMAL POWER PLANT Efficiency Efficiency = Heat Equivalent of Electrical output / Heat of CombustionNormally = 29%Losses:Boiler House Losses:a. To Dry Fuel Gases5%b. To moisture in gases5%c. To ash and unburnt carbon1%d. To radiation and leakage2.5%e. Unknown losses2.5%TOTAL16%Efficiency . . .Turbine Losses:Heat rejection to Condenser54%3.Alternator or Generator Loss1%TOTAL55% Grand Total71%So Efficiency = (100% - Losses) = 100% - 71% = 29%Merits of Steam Power PlantFuel is cheaper*Less space is requiredThe initial cost is lessPlant can be located near the load centreTurbine can work at 25% overload continuouslyA portion of steam can be used in various industriesDemerits of Steam Power PlantMaintenance and operating costs are highPollution of atmosphere is one of the major problemsWater is required in huge quantityHandling of coal and disposal of ash are difficult tasksIt requires long time for installationEfficiency falls quickly below 75%STEAM POWER PLANT LAYOUT

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