Heat Engine

In thermodynamics, a heat engine is a system that performs the conversion of heat or thermal energy to mechanical work. It does this by bringing a working substance from a high temperature state to a lower temperature state. A heat "source" generates thermal energy that brings the working substance to the high temperature state. The working substance generates work in the "working body" of the engine while transferring heat to the colder "sink" until it reaches a low temperature state. During this process some of the thermal energy is converted into work by exploiting the properties of the working substance. The working substance can be any system with a non-zero heat capacity, but it usually is a gas or liquid.

In general an engine converts energy to mechanical work. Heat engines distinguish themselves from other types of engines by the fact that their efficiency is fundamentally limited by Carnot's theorem. Although this efficiency limitation can be a drawback, an advantage of heat engines is that most forms of energy can be easily converted to heat by processes like exothermic reactions (such as combustion), absorption of light or energetic particles, friction, dissipation and resistance. Since the heat source that supplies thermal energy to the engine can thus be powered by virtually any kind of energy, heat engines are very versatile and have a wide range of applicability.

Heat engines are often confused with the cycles they attempt to mimic. Typically when describing the physical device the term 'engine' is used. When describing the model the term 'cycle' is used.

Read more about Heat Engine:  Overview, Everyday Examples, Examples of Heat Engines, Efficiency, History, Heat Engine Enhancements, Heat Engine Processes

Other articles related to "engine, heat, engines, heat engine, heat engines":

Carnot Cycle - Properties and Significance - Carnot's Theorem
... Carnot's theorem is a formal statement of this fact No engine operating between two heat reservoirs can be more efficient than a Carnot engine operating between those same reservoirs ... Equation 3 gives the maximum efficiency possible for any engine using the corresponding temperatures ... theorem states that All reversible engines operating between the same heat reservoirs are equally efficient ...
Timeline Of Heat Engine Technology
... This Timeline of heat engine technology describes how heat engines have been known since antiquity but have been made into increasingly useful devices since the seventeenth century as a better understanding of the ... In engineering and thermodynamics, a heat engine performs the conversion of heat energy to mechanical work by exploiting the temperature gradient between a hot "source" and a cold "sink" ... Heat is transferred to the sink from the source, and in this process some of the heat is converted into work ...
Waste Heat - Sources
... these additional forms of energy are produced by a heat engine, running on a source of high-temperature heat ... A heat engine can never have perfect efficiency, according to the second law of thermodynamics, therefore a heat engine will always produce a surplus of low-temperature heat ... This is commonly referred to as waste heat or "secondary heat", or "low-grade heat" ...
Second Law Of Thermodynamics - Corollaries - Thermodynamic Temperature
... For an arbitrary heat engine, the efficiency is where A is the work done per cycle ... Carnot's theorem states that all reversible engines operating between the same heat reservoirs are equally efficient ... Thus, any reversible heat engine operating between temperatures T1 and T2 must have the same efficiency, that is to say, the efficiency is the function of temperatures only In addition, a reversible heat ...
Heat Engine Processes
... Cycle Process 1-2 (Compression) Process 2-3 (Heat Addition) Process 3-4 (Expansion) Process 4-1 (Heat Rejection) Notes Power cycles normally with external combustion - or heat ...

Famous quotes containing the words engine and/or heat:

    There is a small steam engine in his brain which not only sets the cerebral mass in motion, but keeps the owner in hot water.
    —Unknown. New York Weekly Mirror (July 5, 1845)

    For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe anything but the perception.
    David Hume (1711–1776)