Hello,
I have read the post from http://www.cheresour...sulated-pipe/.
I am trying to develop my own spreadsheet for calculation of a vessel with a cooling water heat jacket. Very similar to the pipe heat loss case only that a convective heat transfer needs to be included for the heat jacket.
I have a terrible confusion while writing the formula of Overall heat transfer = U. I saw that in the file from Proceeng05 first spreadsheet she included all the surface areas for each section of the cylinder, and for the remaining heat transfer calculation Q = DT/U, however for the last sheet, all surface areas were neglected for the calculation of U, and went with the approach Q=UADT
how can you arrive to this conclusion ? and why Q = DT/U not used anymore
For me including all the different surface areas for the calculation of overall U is the right way. Only considering 1 surface area Q= UADT assumes that the resistance between all the surfaces is pretty much the same.
can you please give me a bit of guidance in which formula for U is the correct one
best regards,
yukipilas