[TRNSYS-users] concrete core cooling modelled with active layer

[Pol Olivier]

Dear TRNSYS users,
I am modelling a concrete core cooling (activation of storage mass of slabs) with an active layer (with TRNSYS 16.01).
Relevant data are:
-        distance to edge of the slab: 12cm
-        pipe spacing: 20cm
-        flow mass: 12kg/h.m²
-        Temperature of supply air into the rooms: 19°C
According to the definition of outputs for a surface, the energy abstracted from the room into the slab should be QCOMI and QCOMO (considering both l-wave radiation and convection).
My results are:
-        inlet temperature 19°C, QCOMImax=15W/m²
-        inlet temperature 17°C, QCOMImax=20W/m² (average air temperature in summer: 21°C)
-        inlet temperature 17°C, without cooling of supply air, COMImax=25W/m² (average air temperature in summer: 22°C)
The values I obtain for QCOMI and QCOMO are much lower than the ones obtained in the practice (usually between 40 and 60W/m²).
I tried different variations (simulation time step, distance to the edge of the slab, flow mass and auto-segmentation, internal calculation of convective heat transfer coefficient, number of loops) without success...
Are QCOMI and QCOMO the right outputs?
Thank you for your suggestions,
Olivier Pol.
 
 
 
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arsenal research

Geschäftsfeld Nachhaltige Energiesysteme / 
Business Field Sustainable Energy Systems


DI Olivier Pol

Austria, 1210 Vienna, Giefinggasse 2
ph: +43 (0) 50550-6592, f: +43 (0) 50550-6613
mobile: +43 (0)664/ 62 07 890
olivier.pol at arsenal.ac.at <mailto:olivier.pol at arsenal.ac.at> 
www.arsenal.ac.at <http://www.arsenal.ac.at/> 
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