Fluids

Fluids

Coaxial Underground Heat Exchanger Simulation

    • Eng1989
      Subscriber

      Hello,


      My Name is Ibrahim, I have started simulating a 2d  Axis symmetry Coaxial heat exchanger buried at certain depth. I have few points below which appreciate from you to answer me. The Systems interacting with different component Grout , Soil.


      1) Do I need to build my model first in 3D then i can define my surface by Sluice Cut to model it on 2d.


      2) Do i need to draw my model in Y+ region to avoid any issues with the meshing .


      3) Do i need to draw my model half of it / Completely if it is Axis symmetry. if half how ANSYS will deal with Fluid Surface Boundary.


      4) Do i need to create a thin layer between fluid surface and wall surface Or Wall surface to Wall surface for every interacting components. 


       Thank you very much

    • Vishal Ganore
      Ansys Employee

      Can you show the schematic of your geometry? Are you using coil tubing which is generally used for coaxial heat exchangers. 

    • Eng1989
      Subscriber

      Hi Vganore


       Attached is a sketch for my model, Here actually  no, it is normal Pipe buried on the ground rejecting the heat  to the ground and interact with grout material and soil.

    • Vishal Ganore
      Ansys Employee

      Top view is not shown but I believe you have multiple pipes inserted one inside other starting with inner pipe, insulation, outer pipe surrounded by grout and soil. 


      You could model half of geometry 2D axisymmetric case. 


       



       


      Here is the tutorial showing fluid passing through solid body. Use could solve it using axisymmetric case by creating only half of the geometry. Your model will be similar to this but having multiple fluid and solid body interacting heat with each other. 


    • Vishal Ganore
      Ansys Employee

      Many 3D heat exchanger cases are also available online that could help you if you wish to go with complete 3D model.



    • Eng1989
      Subscriber

      Thx Alot for your support, I really appreciated.


      I have a  Question regarding meshing.  Do i need to define edge meshing for every surface contact. for example Soil surface with grout Surface , Grout surface with Outer Pipe Wall Surface,...etc. As i have done that with my model  and then when i start my setup i got many boundary conditions around 25  which i do not have the enough data to enter it only Just Initial Soil temperature , Fluid Temperature In , Initial Grout temperature. 


      Can you please advise.


      Thx

    • Vishal Ganore
      Ansys Employee

      Defining edge sizing will give you good control in creating mesh. It has nothing to do with BCs. You can share your generated mesh pic or BCs that you wish to apply and relevant location in your model.


      If you wish to share your project file, attach it in Workbench achieve format for further investigation.


       


       

    • Eng1989
      Subscriber

      Hi Vganore,


      Sorry for the delay, Can you have a look for the attached project file.


      Thank you very much.

    • Alidoctor2501091994
      Subscriber
      Hello ibrahim i am ali doctor student i am working on a similar project wish contain coaxial under ground heat exchanger i wish if i can get some help from you thank you .
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