AnsweredAssumed Answered

Heat flow in exchanger not working

Question asked by Yari Wesseling on Dec 15, 2019

Hi,

 

First off, this is probably some rookie mistake as I am a student making this for a school assignment. The assignment requires me to model a counterflow tube-in-shell heat exchanger, and to experiment with different ways to make the heat exchanger more efficiënt. I modeled a heat exchanger constisting of an outer shell and a copper inner tube with a helical fin surrounding it:

I am trying to simulate the temperature of the fluids, i have set up the general settings as follows:

Analasys type: Internal, exclude cavities without flow conditions, and only heat conduction in solids are marked

  • Fluids: only water, laminar and turbulent flow with no cavitation
  • Solids: default solid is insulator (for the outer tube).
  • Wall conditions: adiabatic, 0 roughness. (default settings)
  • Initial conditions: default settings.

In my input data I did the following:

  • Set the solid material of the inner tube (and helix) to copper.
  • Set the inlet velocity of the outer flow (around the helix) to 0.07m/s with a temperature of 80C.
  • Set the inlet velocity of the inner flow (in the copper tube) to 0.05m/s with a temperature of 6C.
  • Set both of the outlets to have environmental pressure.
  • Set a global goal for the fluids and solids temperature (min, max and bulk av).
  • No changes in the mesh.

When I run the simulation, it does simulate the pressure and velocity correctly but the temperatures dont change, thus there being no heat exchanged between the two flows:

My guess is that it has something to do with the parameters regarding the copper solid, but I don't know what exactly.

 

If anyone could help me out, it would be much appreciated .

 

(I'm not a native English speaker so my English might be a bit wrong sometimes, if anything is unclear, I apologise)

Outcomes