Energy devaluation

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Under the energy cancellation refers to the fact, the percentage of usable that for all real energy conversions energy reduced. The devaluation of energy is shown by the fact that such a process cannot take place in the opposite direction by itself .

For example, a rolling ball "loses" kinetic energy because the surrounding area is heated by friction. Another example is the impact of bodies subject to friction: Karl-Eugen Kurrer gave energy devaluation diagrams for these cases when analyzing the internal kinematics and kinetics of vibratory tube mills (elliptical paraboloids). While the entire amount of energy is retained in the closed system in terms of quantity, the internal energy of the ambient heat cannot be used directly. It is also said here that the proportion of anergy increases at the expense of exergy .

In general, energy depreciation occurs in thermodynamic systems as soon as irreversible components occur in ongoing processes . This can be given, for example, by heat conduction . Complete energy depreciation occurs when the temperature difference between two heat storage tanks is equalized by conduction without any work . The (not really possible) Carnot machine works without energy depreciation.

The formulation of the statement of the second law of thermodynamics is equivalent to the language of energy devaluation . The energy depreciation is quantified using the term entropy .

See also

Web links

Individual evidence

  1. ^ Karl-Eugen Kurrer: On the internal kinematics and kinetics of vibratory tube mills . In: progress reports VDI . Row 3: Process Engineering, No. 124 . VDI-Verlag, Düsseldorf 1986, ISBN 3-18-142403-X , p. 58-64 .
  2. ↑ Karl-Eugen Kurrer: For the representation of the energy transformation in the case of a plane coupled friction impact with the help of the energy devaluation diagram . In: Cassius Alexandru, Günter Gödert, Uwe Görn, Roland Parchem and Joachim Villwock (eds.): Contributions to mechanics. Festschrift for the 65th birthday of Prof. Dr. Rudolf Trostel . University library of the TU Berlin, publication department, Berlin 1993, ISBN 3-7983-1581-7 , p. 148-169 .