heat tracing

[picasa]

For a simple finite element model for flow of slurry through a pipe, boundary conditions on the pipe wall need to be decided. The different cases are: 1. Heat traced pipe 2. Steam-jacketted pipe 3. Insulated pipe without any heat input 4. Bare pipe 5. Pipe with color applied to it.

Typically boundary conditions on the pipe wall can be: 1. Constant heat flux 2. Variable heat flux (function of time) 3. Constant temperature 4. Variable temperature (function of time)

Depending on the nature of the different physical cases in the first paragraph, the boundary conditions for the model need to be decided. Any input on how to match the different boundary conditions in paragraph 2 with the different cases in paragraph 1 is appreciated.

 

[vpl]

real life or classroom?

Patricia Lougheed

Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.

 

[picasa]

Real life! We are really interested in solving this problem.

 

[quark]

Pipes with heat tracing and steam jacket - constant heat flux type (if electrical, and may be of varying heat flux type depending upon how bad you maintain your traps)

Pipe with insulation - Constant temperature type as long as the bulk temperature remains constant and ambient conditions don't change severely

Bare pipe - Variable temperature type

Pipe with color applied to it - Constant chroma and aesthetic type

 

[JStephen]

I would say steam jacketed was constant pipe wall temperature. On heat tracing, it would depend on if it was thermostatically controlled or not- if not, constant heat flux. Insulated- constant heat flux of zero. Bare pipe doesn't really match any of your choices up there, which don't seem to include convection/conduction heat loss (ie, heat flux proportional to a temperature difference). Not sure about "pipe with color"- if you mean, "painted", just treat as bare pipe.