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Hi all,
We wanted to model underfloor heating in our multizone house model (Type56). Therefore, we got Type399 from Transsolar. It has the same mathematical model as the Active layer approach in Type56. We successfully implement the Type399 into our house model. Then, we noticed that Type399 doesn't consider the transport delay (example in the attachment). It means that the outlet flow temperature of the floor heating immediately responds to the inlet flow temperature.
When we use a constant flowrate, then transport delay becomes constant as well. ==> Transport delay=(pipe length)/(velocity of the flow). By Type150 (delay function), we can consider the constant transport delay. However, this doesn’t work with variable flowrate because the transport delay is time-dependent and we cannot input the time-dependent transport delay into Type150.
Does anyone have an idea about how to consider the variable transport delay in Trnsys? Basically, we need such a type: https://www.mathworks.com/help/simulink/slref/variabletimedelay.html
Thanks in advance
Yasin
Yasin,
When we have needed finer granularity than the Type56 active layer allows then typically we use Type1267. Type1267 is a finite difference model that allows you to break the floor up into a whole lot of isothermal nodes. You can then specify the nodes through which the radiant piping passes. There are two downsides to that model. The first is that it is NOT easy to set up. You would have to specify the path that each of the pipes in the floor follows. The second is that the model is quite slow to solve because of all the nodes involved.
kind regards,
David
