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Carnot Cycle
 
In 1824, French engineer Sadi Carnot proved that the efficiency factor of an idealized heat engine that is maximal for the given T1 and T2 is defined by the expression
emax = (T1 - T2)
T1

This simulation is designed for the study of a reversible cyclic process in an ideal gas that consists of two isotherms and two adiabats. This cyclic process is known as the Carnot cycle. Carnot cycle is an idealized circular process wherein the working substance (an ideal gas) is periodically brought into contact with a single heater of temperature T1 and a single refrigerator of temperature T2.

A heat engine is a device that converts heat into work. The working substance in any heat engine is brought into contact with a hot body (a heater) in order to get a certain amount of heat Q1 from them. Then, it is brought into contact with a cool body (a refrigerator) in order to give heat away at the amount Q2 < Q1. The process is repeated continuously, which explains its name as a cyclic or circular process.)

No real heat engine working with a heater at the temperature T1 and a refrigerator at the temperature T2 can have the efficiency more than emax.
Remember that a heat engine in a Carnot cycle is at its maximum efficiency when the temperatures of the heater and of the refrigerator are fixed.
ηcarnot = ηmax = (T1 - T2)
T1


According to the laws of thermodynamics, the amount of heat that is acquired from the heaters cannot be completely converted into work (the second law of thermodynamics).

According to the law of conservation of energy, or the first law of thermodynamics, the amount of work W produced by a heat engine is
W = Q1 - Q2
The relationship
e = W = 1 - Q2 < 1
Q1 Q1

is known as the efficiency factor of a heat engine.

Modify the temperatures T1 and T2 of the heater and of the refrigerator, respectively, and observe the ensuing results. The energy diagram displays the quantity of heat Q that is absorbed by the gas, the work W that it does, and the changes in the gas' internal energy ΔU. Take not of the changes in the heat engine's efficiency factor.

 
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