Sunday, August 30, 2009

Hydro power stations

Hydro power station - This power station are mainly used in winter season. The water is the main source of hydro power stations.These power stations are located near to the dam. When water stored above the earth level it contains some kinetic energy. This kinetic energy used to rotate the turbine. Main advantage of this power station is pollution free. Low cost, more reliable.
One major disadvantage is it is not available in summer seasons. It has no wastage. Low speed turbines are used in this type of power station due to low force from water. China constructing one of the biggest hydro power station.
It is expected supply power to more industries. One more disadvantage is that it occupies more space than any other power stations.Now a days water falls are used to generate hydro power.

Monday, August 24, 2009

Thermal Power Stations

Thermal power station - Thermal power station fulfill 65 % electrical energy needs in India. This term is self explanatory. Thermal energy used to generate mechanical energy. Coal is mainly used as a source to produce high pressure steam. The coal is taken from the earth. It cant be used directly for heating purpose as it has so many wastage. It goes under many cleaning process.
Finally solid coal particles are converted in to thin powder so that the boiler efficiency is more. Coal is fired in boiler.Water tubes are placed around the boiler.
This tubes carry water at the end of the boiler high pressure steam is generated.This is high pressure steam is passed to turbine section. Turbine rotates in higher speed.
This hot steam is further used to preheat the coal. This water is again circulated for producing steam. Ash which is the waste from the boiler can be used as a useful material for cement production. Flue gases come out from the boiler can be cooled before send to open atmosphere.

Wednesday, August 19, 2009

Power stations - Types

Types of generating station – generating stations are classified based on the source used. If it is coal and the heat is generated then this type of generation is called thermal power generation. If water is used to generate mechanical energy then it is known as hydro power generation. If the wind power is used to rotate the turbine then this is known as tidal power generation. Earth heat is used to produce steam, which is again used for power generation. This kind is known as geothermal power generation. Sun light is used to generate power generation which is solar power transmission.
Solar power generation requires no maintenance cost. This solar power generation requires high amount of initial capital. No pollution, cost effective is the main advantage of solar power generation. Nuclear power generation is more effective.
The main disadvantage of this type is, the wastage of this generating station can’t be disposed. It gives huge amount of heat energy than coal. It should be located away from
populated area.

Monday, August 10, 2009

Turbines - In Electric power stations

Electrical turbines: It is a rotating engine which gives mechanical energy as rotations to the generator. It consists of larger blades which gets force from the water which is stored above the ground level. In case of thermal power station which gets input from high speed steam which is at the heat of 500 C. In hydro power station this turbines are placed below the dam opening. Whenever dam opened the high speed water hits the turbine and generates mechanical revolutions.
The turbines are designed so that it can withstand any force given by water or steam. In thermal power station turbines, the
metal used is high strength and can’t be corrupted.
The shaft is the center part of the turbine. This shaft is further connected to generator so the mechanical energy directly given to the generator.
The blades of turbine placed in particular angle so that it gives maximum energy when the water hits.

Sunday, August 2, 2009

Generation of Electric power

Generation of electrical power – this is the place where actual power engineering start. There are different types of generation method are there. The types of generation will be discussed later.
The basic principle behind this is, the conversion of mechanical energy in to electrical energy. The reason why we are using electrical power than any other energy is that, it can be converted in to any other form without major difficulties.
We can divide this generation part into three parts. Those are turbine section, generator section, and transformer section. Turbine is connected to generator which gives mechanical rotation to the generator. The side of generator is connected to transformer where step up process taken place. The electrical energy transmission takes place with higher level of voltage and low current to avoid losses due to eddy current. Eddy current losses will be explained when we deal about electrical losses.
Let’s see the input and output of each section.
The turbine gets input from boiler if it is thermal generation or kinetic energy of water if it is hydro power generation. The output of turbine is mechanical rotation which is the input of generator. Electrical power is the output of generator which is connected to the transformer. High voltage electrical power is the output of transformer which is again connected to the transmission line. These three section
s have major operations, which will be seen in future.