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Active Layer and Stack Overflow

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Topic starter

Hello everyone, I have a stack overflow problem with TRNSYS that I believe is related to the radiant floor. I am modeling a condominium with 6 apartments, totaling about 50 thermal zones and therefore 50 nodes. The issue is that each thermal zone has a radiant floor modeled with an "Active Layer," and since the "minimum desired inlet flow rate" is always lower than the "minimum allowed inlet mass flow rate," I performed auto-segmentation for the 50 thermal zones. However, Simulation Studio gives me a "Stack Overflow" error, and when I remove half of the Active Layers, the simulation starts but is extremely slow. I wanted to ask if there is any way to solve this problem.

Additionally, I have another question: If I increase the "minimum desired inlet mass flow rate" so that it is greater than the "minimum allowed inlet mass flow rate" while keeping the inlet mass flow rate as the actual desired flow rate, what would change? Because I noticed that in TRNSYS simulations, it eventually uses "Inlet mass flow rate" as the flow rate, not the minimum or desired values. If this doesn't affect the simulation, I could always set a desired mass flow rate greater than the minimum allowed mass flow rate to avoid having to perform auto-segmentation. Thank you very much, everyone, for your help.

1 Answer
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Yuri,

  It might be a good idea to send your project and any files needed in order to run it to your distributor. They've got tools they can use to find out what the cause of the stack overflow is and, at the least, generate a more helpful error message.

  The "minimum allowed inlet mass flow rate" exists because there are certain ranges over which the active layer model is valid. TRNBuild will have you autosegment the floor based on the default minimum or based on the minimum you tell it you care about (the desired minimum). As you correctly note, segmenting the floor does slow the model down so if the actual flow rate that you want to send to the floor (as an input value) is well above the default minimum then enter a larger value (though still smaller than the actual value you want - just to be safe) and you can prevent the need for autosegmentation. 

kind regards,

 David

 

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