Which of the following power systems are limited by the 2nd

Which of the following power systems are limited by the 2^nd Law of Thermodynamics, i.e., the Carnot efficiency? (You may want to google some of these to understand how they work.) Coal-fired steam power plant Nuclear reactor steam power plant Hydroelectric power plant d) Solar photovoltaic system Turbojet aircraft engine Internal combustion automobile engine Hydrogen fuel cell

Solution

The power systems where heat energy is converted to work will be limited by Second Law.

a) Rankine Cycle is used here.

b) Rankine Cycle is used here.

c) Here the Turbine is rotated by converting the Water Head ( Potential Energy) into Mechanical Energy (Work) which in turn is converted to electrical energy..

d) Here the Solar Energy is converted to Electric energy which in turn is converted to useful work.

e) Brayton Cycle is used here.

f) Otto cycle is used here.

g) Chemical energy is converted to electrical energy to useful work.

Hence a,b,e and f use the principle of converting heat energy directly to useful work and hence they are limited by Second law of Thermodynamics.