25-08-2017, 09:32 PM
GENERATION OF POWER IN A THERMAL PLANT
GENERATION OF POWER IN A THERMAL PLANT.docx (Size: 339.8 KB / Downloads: 45)
THERMAL POWER PLANT
• Thermal Power Plant are those plants which produce electricity by converting heat energy obtained by combustion of non-renewable sources like Coal, Petroleum etc.
• The basic principle behind the working of power plant is that the heat energy obtained from coal is used to get saturated pressurized steam which is then to used to rotate the turbine of electric generator.
• The energy from shaft rotation is collected by a generator which converts the motion to electrical energy using a magnetic field.
BOILER
The boiler is a rectangular furnace. Its walls are made of a web of high pressure steel tubes . Pulverized coal is air-blown into the furnace from fuel nozzles at the four corners and it rapidly burns, forming a large fireball at the center. The thermal radiation of the fireball heats the water that circulates through the boiler tubes near the boiler perimeter. As the water in the boiler circulates it absorbs heat and changes into steam. It is separated from the water inside a drum at the top of the furnace. The saturated steam is introduced into superheat pendant tubes that hang in the hottest part of the combustion gases as they exit the furnace. Here the steam is superheated to 540 °C to prepare it for the turbine.
TURBINE
A turbine is a simple device with few parts that uses flowing fluids (liquids or gases) to produce electrical energy. Fluid is forced across blades mounted on a shaft, which causes the shaft to turn. The energy produced from the shaft rotation is collected by a generator which converts the motion to electrical energy using a magnetic field.
Most power plants use turbines to produce energy by burning coal or natural gas. The heat produced from combustion is used to heat water in boiler. The liquid water is converted to steam upon heating and is exhausted through a pipe which feeds the steam to the turbine. The pressurized steam flow imparts energy on the blades and shaft of the turbine causing it to rotate. The rotational mechanical energy is then converted to electrical energy using a generator.
SURFACE CONDENSER
A condenser is a device which condenses the steam at the exhaust of turbine. It serves two important functions. Firstly, it creates a very low ( By liquidation steam at the exhaust of turbine, a region of emptiness is created. This results in a very low pressure at the exhaust of turbine.) pressure at the exhaust of turbine, thus permitting expansion of the steam in the prime mover to very low pressure. This helps converting heat energy of steam into mechanical energy in the prime mover.