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# Carnot Engine

How does an engine work? Which thermodynamic cycle does it follow? Well, a Carnot cycle is a thermodynamic cycle that gives us the best efficiency possible. It involves two reversible isothermal transitions and two reversible adiabatic transitions. But what exactly is a Carnot engine? Let us study more about it below. Suggested Videos Carnot Engine Principles Carnot principles are only for the cyclical devices like heat engines, which state that: The efficiency of an irreversible heat engine is always less than the efficiency of a reversible one operating between the same two reservoirs.

The efficiencies of all reversible heat engines operating between the same two reservoirs are the same. To increase the thermal efficiency of a gas power turbine, it is necessary to increase the temperature of the combustion chamber. Like, turbines blades cannot withstand the high-temperature gas and lead to early fatigue.

This theorem states that no engine working between two given temperatures can be more efficient than a reversible engine working between the same two temperatures and that all the reversible engines working between the same two temperatures have the same efficiency, whatever the working substance may be.

According to the Carnot theorem, the reversible engine will always have a greater efficiency than the irreversible one. Let the reversible heat engine operate on a reverse cycle so that it’s functioning as a heat pump (or refrigerator). Let the work input to this heat pump be from the work output of the irreversible engine. If you look at this closely, you will see that the net energy exchange in the reservoir This is a violation of the Kelvin-Planck statement of the second law of thermodynamics since there is no heat rejection in a sink, making this a perpetual motion machine of the second kind. This means that our initial assumption was false, thus proving elegantly that the Carnot theorem is correct.

The Carnot cycle is reversible representing the upper limit on the efficiency of an engine cycle. Practical engine cycles are irreversible and thus have inherently lower efficiency than the Carnot efficiency when operating at the same temperatures.

One of the factors determining efficiency is the addition of to the working fluid in the cycle and its removal. The Carnot cycle achieves maximum efficiency because all the heat is added to the working fluid at the maximum temperature.

## The Efficiency of Carnot’s Cycle

The Carnot cycle is reversible representing the upper limit on the efficiency of an engine cycle. Practical engine cycles are irreversible and thus have inherently lower efficiency than the Carnot efficiency when operating at the same temperatures.

One of the factors determining efficiency is the addition of to the working fluid in the cycle and its removal. The Carnot cycle achieves maximum efficiency because all the heat is added to the working fluid at the maximum temperature.

## Carnot cycle

The Carnot engine cycle when acting as a heat engine consists of the following steps: Reversible isothermal expansion of the gas at the “hot” temperature. Isentropic (reversible adiabatic) expansion of the gas. Reversible isothermal compression of the gas at the “cold” temperature. Isentropic compression of the gas.

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