Skip to main content

How does a Carnot Engine work?

In brief, a Carnot heat engine is a type of engine that follows the reversible Carnot cycle. A heat engine is a machine that converts heat or thermal energy, and chemical energy, into mechanical energy. Work is done by moving from a state of higher temperature into a lower temperature (heat is transferred into a heat sink) and work is generated (attached is a generic diagram for this). There is also a heat source...

In brief, a Carnot heat engine is a type of engine that follows the reversible Carnot cycle. A heat engine is a machine that converts heat or thermal energy, and chemical energy, into mechanical energy. Work is done by moving from a state of higher temperature into a lower temperature (heat is transferred into a heat sink) and work is generated (attached is a generic diagram for this). There is also a heat source (can be an exothermic chemical reaction) that brings up the temperature to start the process. A typical example of this type of engine is the steam engine.


A Carnot heat engine is one that operates using the Carnot cycle, and is the most efficient heat engine empirically possible -- it makes use of isothermal and adiabatic processes. There are four steps to a Carnot cycle:


  1. Reversible isothermal expansion of a gas (high temperature). This is the process roughly equivalent to increasing the temperature of the system. Increasing temperature, according to the gas laws, would expand the gas (2nd step). The expansion needs to be reversible because this will allow for maximum energy.

  2. Adiabatic expansion of the gas. This performs the work as the gas expands. It is adiabatic so that the system is thermally isolated and no heat is lost. Temperature starts to go down (heat sink) to the initial lower temperature.

  3. Reversible isothermal compression of the gas (low temperature).

  4. Adiabatic compression of the gas at the lower temperature -- and then cycles back to step 1.

The laws of thermodynamics dictate that this is the most efficient heat engine. (A visualization of the process can be seen in reference 2.)

Comments

Post a Comment

Popular posts from this blog

What is hyperbole in the story "The Gift of the Magi" by O. Henry?

The most obvious use of hyperbole in "The Gift of the Magi" occurs when the narrator describes Della's and Jim's evaluations of their two treasures—her long, luxuriant hair and his gold watch. Had the Queen of Sheba lived in the flat across the airshaft, Della would have let her hair hang out the window some day to dry just to depreciate Her Majesty's jewels and gifts. Had King Solomon been the janitor, with all his... The most obvious use of hyperbole in "The Gift of the Magi" occurs when the narrator describes Della's and Jim's evaluations of their two treasures—her long, luxuriant hair and his gold watch. Had the Queen of Sheba lived in the flat across the airshaft, Della would have let her hair hang out the window some day to dry just to depreciate Her Majesty's jewels and gifts. Had King Solomon been the janitor, with all his treasures piled up in the basement, Jim would have pulled out his watch every time he passed, just to see him plu
Post a Comment
Read more

How can I analyze Moon and Six Pence by Somerset Maugham?

In "Moon and Sixpence," loosely based on the life of Paul Gaugin, Maugham presents a study of the tension between the "civilized" life of 19th century Europe, and the lead character's desire to throw off the shackles of bourgeois life. Charles Strickland is a middle-aged English stockbroker with a wife and family. By abandoning his domestic life, Strickland commits what many in European society would consider a gross betrayal of one of the foundations of... In "Moon and Sixpence," loosely based on the life of Paul Gaugin, Maugham presents a study of the tension between the "civilized" life of 19th century Europe, and the lead character's desire to throw off the shackles of bourgeois life. Charles Strickland is a middle-aged English stockbroker with a wife and family. By abandoning his domestic life, Strickland commits what many in European society would consider a gross betrayal of one of the foundations of that society. His decision to e
Post a Comment
Read more

What are some literary devices in Macbeth, Act V, Scene 1?

Act V, Scene i of Macbeth certainly continues the imagery that is prevalent in the play with its phantasmagoric realm, as in this scene a succession of things are seen or imagined by Lady Macbeth. Imagery - The representation of sensory experience Lady Macbeth imagines that she sees bloody spots (visual imagery) on the stairs; she also smells blood (olfactory imagery): Here's the smell of the blood still. All the perfumes of Arabia will not... Act V, Scene i of Macbeth certainly continues the imagery that is prevalent in the play with its phantasmagoric realm, as in this scene a succession of things are seen or imagined by Lady Macbeth. Imagery - The representation of sensory experience Lady Macbeth imagines that she sees bloody spots (visual imagery) on the stairs; she also smells blood (olfactory imagery): Here's the smell of the blood still. All the perfumes of Arabia will not sweeten this little hand. Oh! oh, oh! (5.1.53-55) Hyperbole - Obvious exaggeration  There is also h
Post a Comment
Read more