[TRNSYS-users] solar boiler as active layer with low flow rates

[leen peeters]

Dear all,

we need to simulate a 'energy roof', i.e. a solar boiler that is like a
floor heating system.
The challenge is that the flow rates are small, i.e. some 15 kg/hr for a
10m2 piece of roof. And thus the standard approach of using the active
layer model does not provide what we need.

So, the question is whether there is a way to get around?
Or can we apply dimensional analysis assuming the active layer acts as a
single volume? In that case:

   - energy in: Q solar
   - energy out: mc(Tout-Tin) via conductive heat transfer from concrete to
   water
   - energy content: C(deltaT/delta t)

Does that mean we can estimate the results with a flowrate m1=m/10 using
the appraoch of adapting as follows:

   - Qsolar*10
   - energy content: c*10
   - energy out: apply conductivity lambda * 10 and use m instead of m'

and that this would give us an estimate of m' -results?

thanks already,

leen
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