![]() And of course this quantity cannot be stored, only the energy moved by it can be stored.Īnd the crucial point is: Transferring energy as heat into a system is fundamentally different from doing the same by work. From a thermodynamics point of view heat is a process quantity that describes a certain way by which energy can be transferred across the boundary of a system. This line of argument, however, violates at least two principles of thermodynamics and misses the crucial point. This can best be done by showing the advantages of including entropy in a heat transfer analysis as well as showing the disadvantages one has to face when entropy is ignored.Įngineers, using the phrase “heat transfer”, would not be bothered by the view that heat is moved across the boundary of a system and then stored in it, increasing its heat content. In thermodynamics the relevance of entropy with respect to heat transfer is beyond any controversy, it is the heat transfer community that has to be persuaded of its relevance. What is true is a yet open question and can only be answered when thermodynamic considerations are taken into account. ![]() ![]() There may be two reasons for that: Either entropy has turned out to be irrelevant for a heat transfer analysis or entropy is ignored deliberately in the heat transfer community in spite of its relevance. If, however, you do the same with a standard textbook on heat transfer (like with 1024 pages or with 1107 pages), you will find entropy neither in the index of these books, nor in the text. Indicating that the (process) quantity heat ( δ Q ) is obviously closely linked to the (state) quantity entropy ( d S ), here both written as infinitesimal quantities. ![]()
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