Interesting heat transfer Problem
Interesting heat transfer Problem
(OP)
Wondering if anyone has modelled this common heat transfer problem? Basically it is a Dead Zone at the end of a pipe run, as shown,
Pipe run & branch is say, 20" pipe, 35C water flows from A thru the pipe branch C and all is good on those runs, flow is continuous and assume stays at 35C.
The downstream zone B is dead head and many times if its only a few feet long, ~ 1-3 pipe dia long, it doesn't freeze but of course after a certain length it does freeze,
I modelled it as a complex "Fin", Q into dead zone = Q out of dead zone etc,
Qin is not much, water is a poor conductor, there is some turbulence at the junction so get some mixing, convection, but still poor transfer here,
Q out is simpler, but water temp varies along dead zone length,
Has any one modelled it differently?
Ideas?
^ C
| -30C ambient
A | B
---->-----------------------||
pipe tee
Pipe run & branch is say, 20" pipe, 35C water flows from A thru the pipe branch C and all is good on those runs, flow is continuous and assume stays at 35C.
The downstream zone B is dead head and many times if its only a few feet long, ~ 1-3 pipe dia long, it doesn't freeze but of course after a certain length it does freeze,
I modelled it as a complex "Fin", Q into dead zone = Q out of dead zone etc,
Qin is not much, water is a poor conductor, there is some turbulence at the junction so get some mixing, convection, but still poor transfer here,
Q out is simpler, but water temp varies along dead zone length,
Has any one modelled it differently?
Ideas?
^ C
| -30C ambient
A | B
---->-----------------------||
pipe tee





RE: Interesting heat transfer Problem
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RE: Interesting heat transfer Problem
RE: Interesting heat transfer Problem
RE: Interesting heat transfer Problem
Will look at insulation and see, otherwise will need tracing, I agree with you that we should ignore any other gain in heat at the tee other than straight conduction.
Thanks again, Hope all is well,
JL
RE: Interesting heat transfer Problem
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RE: Interesting heat transfer Problem
It was hard to calculate the steady-state equilibrium condition in one step. I used various water temps, then repeat till heat gain (conduction) equaled heat loss (outer surface) and doesn't equal above 0C at wall.
Thx,
RE: Interesting heat transfer Problem