The heat transfer paradox is an unexpected phenomenon in thermodynamics from an ordinary point of view, that when using a heat exchanger a paradoxical effect can be obtained and the substance to be heated will have a temperature higher than the substance from which heat is taken, and this is without external energy consumption.
History
This paradox is given in the book by VN Lange as a problem in molecular physics and heat . The solution to this paradox is also given there [1] . The essence of the solution lies in the fact that a small part is separated from the heated liquid and brought into thermal contact with the cooled liquid. After the onset of thermal balance between this part and the cooled liquid, it is again disconnected and placed separately. Then the next part is separated from the heated liquid and comes into thermal contact with the cooled liquid (already cooled a little at the previous stage). And again, after the onset of heat balance, this part of the heated liquid is separated and placed together with the previous part. As a result of such heat exchange “in parts”, the final temperature of the heated liquid will be higher than the final temperature of the cooled liquid.
Other variations of this paradox are included in the "golden fund" of elementary physics [2] .
Application
This phenomenon has found wide application in heat engineering, in particular when creating and using heat exchangers . For the first time this effect in 1857, Wilhelm Siemens used in his piston expander (although not very successfully), which was a significant contribution to the overall development of low-temperature equipment [3] [4] . Later, Peter Kapitsa used heat exchange in counter flows in a cryogenic plant, in which the efficiency of the heat exchanger reached 92% [5] .
Notes
- ↑ V.N. Lange. Physical paradoxes, sophistry and entertaining tasks. Moscow, 1967, pp. 35, 110-111.
- ↑ Moscow Physical Center. "Tasks and paradoxes".
- ↑ N.N. Agapov. Nature. No. 4, 1994
- ↑ Charles William Siemens, "Improvements in refrigerating and producing ice", British patent no. 2064 (filed: July 29, 1857).
- ↑ P. L. Kapitsa. Adiabatic method of helium liquefaction. UFN, t. 16, issue 2, 1936 (p. 152)