COMPLEX MECHANICAL SYSTEMS
. Coal handling system. Steam generation system. Power generation system. Feed generation system. Ash water system. Steam condenser system. Draught system. Air distribution systemO COAL HANDLING SYSTEM
The coal handling system is the most important functionary part thermal power plant. TheSteps involved in the coal handling system are as follows:. Coal delivery. Unloading. Preliminary coal preparation. Outdoor storage. Covered storage. In plant handling. Dust control system. Palavering. Feeding the coal into furnace O STEAM GENERATION SYSTEMCoal handling plant sends the prepared coal to steam generation system. In this system, coal is burnt and heat thus produced is transferred to water. The unit in which water is converted into superheated steam. This section is comprised of various units like furnace, boiler drum and tubes, super heater coils, reheater coils and heat reclaiming device. Different types of boilers are available which can be used. But now day's high pressure boilers are being used in the thermal power section. The maximum pressure in these boilers is about 126 kg/cm2.
O POWER GENERATION SYSTEMThe steam produced in the boiler is sent to the steam turbine where thermal energy is converted into mechanical energy. The steam turbine consists of a rotor having a series of blades on its circumference. The blades are made to withstand the action of steam and the centrifugal force. The rotor is rotated by the steam striking against the blades. As the steam expands in nozzle, it gains the high velocity. This energy is converted into mechanical energy. As the steam turbine is directly coupled to the dynamo and convert the mechanical energy into electrical energy.
O FEED WATER SYSTEMRaw water for power station is taken from western Yamuna Canal (WYC) by a channel. This water is lifted by water pumps and fed to clarifiers to remove the turbidity in water. The clear water is stored in clear wells from where it is to be sending to water treatment plant, cooling water system and service water system the water on treatment plant is filter and demineralised.The condensate from the condenser is used as feed water to the boiler. Some water is lost throughout the cycle from blow down leaks etc. The loss varies from 1 to 3 % during normal operation and 5 % during start up period.A separate water softening plant is required to supply this from a river as well as a lake. The water supplied by water softening plant is of very high quality (10-50) PPB silica and less than 500 ppb total solid content).The impurities cause corrosion and erosion of boiler tubes, turbine blade and blockage in the boiler tubes resulting tube failure due to overheating.
O ASH HANDLING SYSTEMIn thermal power plant a large quantity of ash is produced. The quantity of ash produced is about 10-20% of total coal burnt. The as his first quenched and then disposed with help of ash handling system.
O DRAUGHT SYSTEMThe purpose of the drought system is to supply require quantity of air for combustion and removed the burnt products from the system for flowing of gases through different units, pressure difference is essential. The difference of Pressure required to maintain constant flow of air and to discharge the gases through the chimney to atmosphere is known as drought.Drought can be produced naturally by chimney but it is not sufficient and mechanical drought systems of induced and forced types are generally used. The ID (induced drought) fans and FD (forced draught) are used for this purpose.
O STEAM CONDENSER SYSTEM
The steam condenser system basically improves the efficiency of the thermal power plant by decreasing the exhausts the pressure of the stream below atmospheric pressure.The water obtained from condensers is used in boilers again. The condenser system place vital role in thermal power plant. Therfore, the reliability analysis of steam condenser system is of great use. The results of this analysis can be used while designing new plants.
Origin: greenenergychoice.blogspot.com
