What is the entropy of Carnot engine?

In order to approach the Carnot efficiency, the processes involved in the heat engine cycle must be reversible and involve no change in entropy. This means that the Carnot cycle is an idealization, since no real engine processes are reversible and all real physical processes involve some increase in entropy.

What is the formula of Carnot engine?

W=QH−QC=(1−TCTH)QH. efficiency =WQH=1−TCTH. These temperatures are of course in degrees Kelvin, so for example the efficiency of a Carnot engine having a hot reservoir of boiling water and a cold reservoir ice cold water will be 1−(273/373)=0.27, just over a quarter of the heat energy is transformed into useful work.

How do you calculate the temperature of a Carnot sink?

1 Answer

1. Given: η = 25%
2. Temp of sink = T 2 = 27 °C = 300 K.
3. As η = 1 – (T 2 / T 1)
4. ∴ (1/4) = 1 – [(300) / T 1]
5. ∴ (3/4) = [(300) / T 1]
6. ∴ T 1 = 400 K.
7. i.e. Temp of source = 400 K = 127 °C.

What happens to the entropy of a Carnot engine?

The entropy remains the same. Heat shifted reversibly to a low-temperature pool at constant temperature TC. (isothermal heat elimination) (3 to 4 on image 1, C to D on image 2) Now the gas in the engine is in thermal contact with the cold pool at temperature Tc.

How is the Carnot efficiency of a heat engine calculated?

Note: Unlike the earlier equations, the positions of T cold and T hot are reversed. The Carnot Efficiency is the theoretical maximum efficiency one can get when the heat engine is operating between two temperatures: The temperature at which the high temperature reservoir operates ( T Hot ).

How is a reversible heat engine different from a Carnot cycle?

The reversible heat engine works on a reverse cycle and behaves as a heat pump. The Carnot cycle is reversible signifying the upper limit on the efficiency of an engine cycle. Practical engine cycles are irreversible and therefore have inherently much lower efficiency than the Carnot efficiency when working at similar temperatures.

What is the temperature at the end of the Carnot cycle?

A Carnot engine absorbed 1.0 kJ of heat at 300 K, and exhausted 400 J of heat at the end of the cycle. What is the temperature at the end of the cycle?