Subsection 10.6.7 Reversible Heat Engines
A reversible process is defined as a process that can be reversed without leaving any trace on the surroundings. It means both system and surroundings are returned to their initial states at the end of the reverse process. Processes that are not reversible are called irreversible.
Reversible heat engine is just the heat engine which is running in the reverse direction of heat engine. In reversible heat engine all the three components re-assume exactly their original conditions and no changes are left in the surroundings. Such an engine can be realized if, the engine is free from friction, the process is infinitely slow, and working substance never differs appreciable from its surroundings. No heat engine can have efficiency greater than a reversible heat engine.