2 Replies Latest reply on Jul 31, 2018 4:46 PM by Art Thorsby

    Seeking guidance on setting up FLOW sim on a shell & tube chiller evaporator. 

    Art Thorsby

      Seeking guidance on setting up FLOW sim on a shell & tube chiller evaporator.  Purpose of the test is to create a base-case control model for comparison to a new tube design.

      My model has a fluid subdomain for the water flow through the tube side.  The shell side is R134a refrigerant.  I understand that FLOW cannot do "phase change" in the refrigerant.  I will adjust the refrigerant flow/pressure/temp to get close to the 10 degree f DT on the tubes.

      Problem I am running into is with Wall Condition.  As I am searching for correct heat transfer through the tube wall I want the Copper material properties to drive the heat transfer.  If I apply a heat transfer coefficient, heat generation rate, or wall temp it defeats the test intent.  If I leave the Wall Condition at the default Adiabatic there will not be any transfer through the tube wall. Also attempted analysis type "External" and went into space. 

      Any guidance will be most appreciated.

      Thank you,

      Art

        • Re: Seeking guidance on setting up FLOW sim on a shell & tube chiller evaporator. 
          Ryan Navarro

          Hi Art,

           

          The default wall condition in the Project Wizard applies only to the outer walls. So you could add some h value there if you want to compensate for heat loss to atmosphere, and don't want to run the analysis as external- but other than that it is not required.

           

          Based on what you are describing all you should need to do is set up the Internal analysis with the Fluid Subdomain which it sounds like you already have.

           

          Make sure "Heat conduction in solids" is enabled in the project options. Then specify your wall material as Default Solid. Or if you have mixed materials you can apply multiple Solid Materials separately. This will take automatically take into account the thermal conductivity of the various solids.

           

          There is a tutorial in the software that is also very relevant, in the Flow Simulation Tutorials PDF (Help -> SOLIDWORKS Simulation -> Flow Simulation Online Tutorial) example B3 for Heat Exchanger Efficiency

           

          If you do want to define the analysis as external, you will need to use TWO fluid subdomains and also make sure that only Air is specified as the default fluid.