Burried pipes
Burried pipes
(OP)
Anybody know any good correlations (pref. with a litterature ref.) for a aproximation of the heat loss from a buried pipe where the value should be a heat resistance coefficient R or equivalent (so that the value can be incorporated in a standard U estimation).
I know the one that is often seen lifted from the "Transactions of the American Institute of Electrical Engineers, The temperatures of buried Caples and Pipes" Volume 68, Part I 1949" that are commenly used. But i have been told that it is inaccurate at low pipe temperatures.
Best Regards
Morten Andersen
I know the one that is often seen lifted from the "Transactions of the American Institute of Electrical Engineers, The temperatures of buried Caples and Pipes" Volume 68, Part I 1949" that are commenly used. But i have been told that it is inaccurate at low pipe temperatures.
Best Regards
Morten Andersen





RE: Burried pipes
For bare pipe buried in soil, depth z to center, Rp is pipe radius, k is soil conductivity, Ts is temperature at surface, Tz is temperature at pipe depth, Tw is temperature of fluid in pipe;
Rg=[arccosh (z/Rp)]/2*pi*k;
and q=(Tw-Ts)/Rg ---heat loss per unit length