Heat transfer coefficient 3

[jproj]

I am currently working on some insulation thickness calculations (trying to develop a spreadsheet) and need some help in determining a heat transfer coefficient. The tank (horizontal carbon steel) is a little more than half full of saturated liquid with saturated steam in the head space (51 psia @ steady state). I have the thermal conductivity of steel and the insulation, but I am not sure how to calculate the heat transfer coefficient from the liquid & steam to the shell. I really haven't looked into it yet, but I would assume that I need the same type of help calculating the heat transfer coefficient from the outside insulation surface to the ambient air.

My thinking is that from the liquid to the shell is conduction, while the steam is convection (and maybe radiation?). If someone could point me in the right direction, it would be much appreciated.... heat transfer was definately not my forte in college!

jproj

 

[chicopee]

For your problem,I would not consider the convective heat transfer coefficient for the inner surface of the storage tank. Use the bulk temperature(saturation temperature) of the medium as the inner surface temperature of the shell. If it is a thin shell vessel you may even use that saturature temp. as the inner surface temp. of the insulation and entirely dismiss any temp loss thru vessel wall.