Faux Carnot Theorems, mythology of disappearing energy

   Previous Next

What did Sadi Carnot NOT say about the Carnot Cycle? Too many leaps of Flaw.

Where to start

There are so many things wrong with this its hard to decide where to begin and where to stop. So, rather than repeat items elsewhere documented, lets focus on what Sadi Carnot actually said.

First and foremost, Sadi Carnot is not the author of the "Carnot's" Theorems.

Neither the Work Ratio known as Carnot ratio appear, nor the theorems attributed to Carnot anywhere in Sadi Carnot's published works. To name these "Carnot's" theorems is a kind of reverse plagiarism, taking his name instead of his words.

Specific references appear elsewhere in FuelScience.org, so will not be redundantly copied here. In summary, Sadi Carnot and Lord Kelvin both say multiple times in multiple ways:

  • The math of the Carnot Cycle applies to all air and steam engines.
  • The properties of the Carnot Cycle (reversibility, etc.) are properties all air and steam engines.
  • The maximum work derived from a quantity of heat of any heat engine whatsoever is the same as the maximum power derived by any air or steam engine.
  • The amount of Work produced is proportional to the amount of Heat consumed.

 

Faux Carnot

(Faux) Carnot's theorem, (not) developed in 1824, also called Carnot's rule is a principle that specifies limits on the maximum efficiency any heat engine can obtain, which thus solely depends on the difference between the hot and cold temperature reservoirs.
Carnot's theorem states:

  1. All irreversible heat engines between two heat reservoirs are less efficient than a Carnot engine operating between the same reservoirs.
  2. All reversible heat engines between two heat reservoirs are equally efficient with a Carnot engine operating between the same reservoirs.

The formula for this maximum efficiency is The Work Ratio, Aka the Carnot Ratio.

Where Carnot Ratio = Work ratio = 1 - Heat Ratio,
where Heat Ratio = Temperature of Cold Reservoir/ Temperature of Hot Reservoir

Footnote: Everywhere FuelScience.org refer's to Carnot's Theorems, the meaning is theorems of thermodynamics attributed to Sadi Carnot. Not to be confused with Lazare Carnot's theorems of geometry and mathematics, also commonly ambiguously referred to as "Carnot's theorem".