How can I consider the changing temperature of a copper object that is being cooled by coiling a pipe around the outside surface?

Hi,

It looks like many of the heat exchangers offered in simscape require another fluid or gas. So that doesnt quite get the job done. I'm currently using a Pipe (TL) with convection, conduction, and a Temperature Source (see image). The temperature source provides a constant outside temperature but I need to model the changing temperature of the object.

Any suggestions are greatly appreciated!

AJ

Answer 1

[Yifeng Tang]

The heat transfer between solid objects are best represented by conductive components and thermal mass. I suspect the thermal mass is what's missing right now.

Also, note that the pipe component has a convection wall model for heat transfer inside. So the pip "wall" temperature may not be the fluid temperature. The conductive heat transfer you have there will add onto the existing correlation. Just to make sure you are aware.

[AJ Purvis]

Thank you for writing back! I'm still a bit confused by how to incorporate a thermal mass. Can you tell me if what I have laid out below is correct?

Hot copper object -> Hose wrapping around copper object -> Fluid flowing through hose

Thermal Mass node > Conductive Heat Transfer node outlining properties of the hose > Pipe (TL)

Should there be another Conductive Heat Trasfer node to outline the properties of the heat transfer taking place in the copper, or is accounted for within the Thermal Mass node?

[Yifeng Tang]

I think you got it right. Also remember to set the initial conditions in the "variables" tab of the thermal masses to set the initial temperature, in order to get the right transient.

And the thermal mass will NOT have any temperature distribution within itself. Each block is a "lump" model. So if you are interested in the conduction inside the copper mass, which may be important depending on the Biot number. In such cases, you'll need to model the copper mass with several thermal masses with conduction blocks in between (think of several shells/layers to form a sphere).

[AJ Purvis]

I'll work on that and see if it produces some results! Thanks for all your help

[AJ Purvis]

So I've been working on this all day and I'm still not getting any significant drop in temperature from point A to point B on the Pipe (TL). I looked into a heat flow rate source and played with the values a bit with no luck.

With such a high beginning temperature of the copper object represented by the thermal mass, there should be a significant significant rise in temperature and pressure at the end of the pipe.

Currently the scope only shows -0.01 K change in temperature.

Again, your help is invaluable. Thank you for working with me.