Generally we use fin for rejection of heat by increasing surface area. Can we use fin as heat addition source?Fin is attached at outer surface of pipe. Heat will flow from pipe to fin. Let us suppose we reverse the direction, is it possible to add heat from fin to pipe? Please explain with example.
Fins are used in applications when the values of heat transfer coefficients are small or where the surface area for heat transfer required is large. It is possible "to add heat from
It is possible "to add heat from the fin to pipe" as in the case of a solar air heater. Even in a flat plate collector, the analysis is undertaken from the fins transferring heat to the tube.
If you have a large distributed heat source and you want to transfer heat to a smaller size sink in that case you may use fins to capture the heat and transfer it to pipe and then to the material inside.
Idea behind using Fins is to increase surface area for the heat transfer and hence it augments heat transfer. Whether heat will be transferred to the body where Fins are attached or from the body, depends on the temperature difference between body and the surrounding fluid. If the temperature of the fluid is higher , then yes Fins will help in increasing heat transfer to the body.
Fins with some kind of heating source (either inside or from outside) can be introduced for heat addition purpose, but with many precautions. I am also agree with Dr. Jagmohan Singh's answer on this.
Heat transfer coefficient is the most important parameter while deciding whether fins should be placed on the inner side or in the exterior portion.Whichever side(inner or outer side ) has lesser heat transfer coefficient we will place our fins in that side.
So,to answer your question,Yes,we can use fins in the high temperature side(heat addition source).
For example..in refrigeration; for water cooled condensers, refrigerant is flowing through the tubes and rejecting heat to the surrounding fluid which is water in this case.So,in this scenario where should we use fins??....Fins will be in the inner side of the tubes because heat transfer coefficient for the refrigerant will be much lower as compared to the heat transfer coefficient for water.
But the problem with this kind of configuration is higher pressure drop inside the tubes.So we have to design the condenser accordingly.
i hope you understood what i am trying to say.
Good luck
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