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Hi everyone,
I would like to modelise the stratification of air in a werahouse. I do not own TRNSYS 3D so I modelised the building by creating a new file multizone building type 56 with a single zone. By doing so, I stated the dimensions of the building (length, width, height) and all the required parameters.
My goal then was to measure the several parameters such as the temperature at different height in the room and 3 issues appeared :
- I tried to create another airnode in the same zone but I was not able to size the airnode and even if I could, I had to create a wall between the two airnode with causes problemes stratification (no convection only conduction).
- I then tried to create multiple zone one on top of the other, but the same issue appeared, I had to create a wall between the zone.
- I read on internet I could try to simulate the model by putting a heat exchange composant but I was not able to do it.
If someone have any clue how to simulate such a thing or did it already, it would save my school project 🙂 .
Thank you
Arthur
Arthur, I must admit I have not tried this without using Trnsys3d but the usual process would be to create two zones maybe sitting one on top of the other with an ADJACENT "wall" between them. TRNBuild then offers you the possibility to combine two airnodes into a single thermal zone. You open the main window for the airnode that you want to combine with another and in the upper left corner you'll see a button with an arrow shaped like a "U." Click on that button and you'll be able to combine the airnode with another. Once you do then the wall between the two will be deleted and you'll need to click on the "coupling" button in order to define the air flow between the two airnodes.
The question quickly becomes how to determine how much air flow occurs between the two nodes. The simple part of the answer is that you can use either CONTAM (Type97) or TRNFlow to determine the amount of air flow. The more complicated part of the answer, though, is that both CONTAM and TRNFlow only allow for there to be unidirectional flow through a large horizontal opening at any given point in time. In reality, of course, there is bidirectional (mixing) flow. You'll find a fair amount of literature online suggesting methods for coping with that limitation. I have tried a few of them but don't have a recommendation as to one that I think is more correct.
kind regards,
David
