Correct Answer - Option 3 : 30%
Explanation:
The efficiency of various power plants are given below:
|
Steam thermal power plant
|
28 – 35%
|
|
Nuclear power plant
|
40 – 45%
|
|
Diesel engine power plant
|
35 – 42%
|
The overall efficiency of the steam power plant is given as
\(Overall\;Efficiency\;\; = \frac{{Electrical\;energy\;output}}{{chemical\;energy\;input}}\)
Overall efficiency is also expressed as
\({\eta _0} = \;\frac{{Thermal\;Energy}}{{Chemical\;Energy}} \times \frac{{Mechanical\;Energy}}{{Thermal\;Energy}} \times \frac{{Electrical\;Energy}}{{Mechanical\;energy}}\)
So, the overall efficiency of the power plant is equal to the multiplication of the efficiencies of the boiler, turbine, and generator.
Overall Efficiency = Boiler efficiency × turbine efficiency × generator efficiency
ηpower plant = ηboiler × ηturbine × ηgenerator
Where,
Boiler efficiency = Thermal efficiency
Turbine efficiency × Generator efficiency = Electrical efficiency
