Buried Pipeline Heat Transfer
Buried Pipeline Heat Transfer
(OP)
I am working on the following problem:
I have a buried pipeline at -5C which is causing a layer of soil X meters above it to freeze after a specified time period. The soil is initially at 5C and known is all the thermal data. In order to model this, I decided to consider the soil as a semi-infinite solid and consider the system to be 1-D transient.
The equation is: (T-To)/(Ts-To) = erfc(y/2sqrt(kt))
My problem is, as the pipeline causes the soil (and water) to freeze, it will create an insulating effect on the pipe... which I currently am not taking into account. Does anyone have any advice for me as to how to handle this situation?
I have a buried pipeline at -5C which is causing a layer of soil X meters above it to freeze after a specified time period. The soil is initially at 5C and known is all the thermal data. In order to model this, I decided to consider the soil as a semi-infinite solid and consider the system to be 1-D transient.
The equation is: (T-To)/(Ts-To) = erfc(y/2sqrt(kt))
My problem is, as the pipeline causes the soil (and water) to freeze, it will create an insulating effect on the pipe... which I currently am not taking into account. Does anyone have any advice for me as to how to handle this situation?





RE: Buried Pipeline Heat Transfer
“Construction in Cold Regions,” McFadden & Bennett
Numeric method required the use of several graphs for some of the properties:
Soil conductivity, frozen or thawed
Dry density of soil
Moisture content of soil
Latent heat of fusion of the water
Soil thermal mass
Value from modified Berggren equation
References for the method:
Lunardini 1988
"Permafrost Engineering Design and Construction," Johnston 1981
RE: Buried Pipeline Heat Transfer
Degree days for freezing or thawing
RE: Buried Pipeline Heat Transfer
I am pretty new to this industry... and I would like to know if anyone with experience, could give me a rough estimate at how much frozen ground a pipeline like this would cause? Are we talking, 6", a couple feet, a couple of meters?
-5C pipe, 5C wet soil
Lets say I am looking for a relatively rough estimate for this calculation. Would the following be a sound method for determining the depth of frozen ground?
- find a heat transfer coefficient for the pipe and contents
- then use the htc to get a heat flux into the pipe
- using that heat flux, use fouriers law and get a temperature profile
- finally, using the temperature profile... just find the point at which T = 0C, and everything below that would be frozen.
This is assuming a linear temperature profile and a bunch of other simplifying assumptions, but for a rough estimate, would that result be terrible?
Thanks.
RE: Buried Pipeline Heat Transfer
RE: Buried Pipeline Heat Transfer
RE: Buried Pipeline Heat Transfer
http://www.ccb.org/docs/COETM/5_852_5.pdf
RE: Buried Pipeline Heat Transfer
RE: Buried Pipeline Heat Transfer