Merits and Demerits of Thermal Power Plant.

 

MERITS AND DEMERITS OF THERMAL POWER:

MERITS

DEMERITS

Transmission cost of thermal power is much less compared to hydel power because thermal power stations are located closer to the distribution. Thermal power production is more demand-driven and can accommodate daily, seasonal and annual fluctuations and peaking requirements. Thermal power stations can be designed and constructed in relatively less time and therefore, are planned for short/ medium-term needs. Mostly, thermal power stations do not calls displacement problems. Initial capital cost of thermal project is relatively less, compare to hydel projects.

The cost of power per unit from a thermal power station is much higher compare to hydel and in the longer term, thermal becomes an expensive proposition. Thermal power stations use non-renewable fossil fuels as raw material. SO2 ,  NOx, particulate matter pollution is big problem from thermal power stations. In case of Pakistan, thermal power production is a burden on the national economy because its raw material has to be imported, which consumes a huge amount of foreign exchange. Thermal power stations do not add towards recreation, esthetics, wet lands, fisheries, etc.

Sponsored by:
www.funtostudy.com
Revolutionizing Education

What is Nuclear Power plant?

NUCLEAR POWER PLANT:

Nuclear power is the energy derived from the fission of the nuclei of heavy elements such as Uranium, Thorium etc. the amount of energy released per atom exceeds by a factor of several millions the amount of energy obtained per atom in a chemical reaction, such as the burning of fuel. 

Nuclear Reactor:

           

The first large-scale nuclear reactors were built in 1944 at Hanford, Washington, for the production of nuclear weapons material. The fuel was natural uranium metal, the moderator, and graphite. Plutonium was produce in these plants by neutron absorption in uranium-238; the power produced was not used.

This plant being built at chasma in northern Pakistan is on a water body. In case of a nuclear accident and leakage into the river, there is good chance for radioactivity will affect all agriculture down-stream.

Sponsored by:

www.funtostudy.com

Revolutionizing Education

What is Combined Cycle Power Plant?

COMBINED CYCLE POWER PLANT:

Combined Cycle Generation, system of electricity generation that makes use of both a gas turbine and a steam turbine. Combined cycle power plants are more efficient than conventional power plants, with an energy conversion efficiency of around 40 percent (compared with under 38 percent for conventional plants).

In combined cycle generation, the gas turbine is powered by burning gas fuels and turns as electric generator. The exhaust gases are then used to heat water to produce steam. The steam powers a steam turbine attached to an electric generator, producing additional electricity. Simple cycle operates near max power because they ate not uses in service where efficiency is the prime concern. Regenerative cycles, however, are meaning full only if they are operated near max efficiency. Thus they would have their output reduced from a simple cycle by a much larger percentage, perhaps 10-14 %. In certain applications, an economic compromise b/w capital and operating cost would have to be found.

It can be seen that raising the efficiency of a gas turbine plant by regeneration, while used for stationary applications is costly. A means, therefore, was sought whereby both efficiency and power are increased. The solution was found I using the large quantity of energy leaving with the turbine exhaust to generate steam for a turbine power plant. This is natural solution as the gas turbine is a relatively high temperature machine (1100-1650 C) where as a steam turbine is a relatively low temp machine (540-650 C). This joint operation of a gas turbine at the “hot end” and the steam turbine at the “cold end” is called a combined cycle power plant.

Besides both high efficiency and high power output, combined cycles are characterized by flexibility, quick part-load starting, suitability for both base load and cyclic operation, and a high efficiency over a wide ranged of leads. They have the potential of using coal as well as synthetic and other fuels. Their obvious disadvantage is in their complexity, as they in a sense combine two technologies in one power-plant complex. The idea of combined cycles is cot new, having been proposed as early as the beginning of this century. It was not, however, until 1950 that the first plant was installed. This was followed by a rapid rise in the no of installations, especially in the 1970s.

Sponsored by:
www.funtostudy.com
Revolutionizing Education