[TRNSYS-users] Type 56 active layer error : inlet fluid mass flow to low (simulating concrete core activation)

["Maeriën, Pieter"]

Hi!
I'm currently trying to simulate concrete core activation in a multi-zone building.
But when I input a certain mass flow rate into the active layer, the mass flow needs to be above a minimum value!?!
This is strange since there should be no minimum flow rate, in reality flow rates can vary from zero to a limited flow rate maximum!
What causes this error and/or is there a known workaround?
I work with prebid 5.0.8 and trnsys 15 with iisibat 3 (version 3.0.0.26) Reg. Num.=15B-B011
Thanks!
Pieter

BASIC INPUTS (see also .lst-file in attachment)
Wall (ceiling) with active layer:
0.10m concrete
0.00m active layer (0.20m pipe spacing, 0.02m diameter, ...)
0.15m concrete
0.20m mineral wool
Active layer specifications:
Inlet temp 20C
Inlet mass flow rate 500 kg/h
Number of fluid loops 10
(additional) Gain 0 kJ/h
Area 100m2

These inputs generate the errors below.
Other values generate the same error, but with different minimum values of the specific mass flow rate (eg. 0.10m pipe spacing and inlet flow rate 2000kg/h : below min value 27.79kg/m2h error)


 ***** ERROR *****        TRNSYS ERROR # 
 UNIT   7 TYPE  56 MULTIZONE BUILDING
 SPECIFIC FLUID MASS FLOW OF ACTIVE LAYER IN SURFACE   7 BELOW MINIMUM VALUE OF  6.58 KG/M2H.
  SIMULATION STOPPED.
  PLEASE REPLACE THIS WALL WITH TWO OR MORE WALLS OF THIS TYPE AND CONNECT THEM
  IN SERIAL FLUID FLOW WITHIN THE DECK FILE BY CONNECTING ADEQUATE INPUTS AND OUTPUTS TO TYPE 56.


 ***** ERROR *****        TRNSYS ERROR # 191
 UNIT   7 TYPE  56 MULTIZONE BUILDING
 SUBROUTINE INVERT WAS CALLED FROM SUBROUTINE INVPAR WITH A SINGULAR
 MATRIX.


 ***** ERROR *****        TRNSYS ERROR # 191
 UNIT   7 TYPE  56 MULTIZONE BUILDING
 SUBROUTINE INVERT WAS CALLED FROM SUBROUTINE INVPAR WITH A SINGULAR
 MATRIX.


Pieter Maerien
ir. architect 

Arteum Architects
Frans Smoldersstraat 18
B	1932 Zaventem
T	+32 2 711 28 69
F	+32 2 725 45 02
E	pieter.maerien at grontmij.be <mailto:voornaam.naam at grontmij.be> 
W	www.grontmij.be

 <<NewProject2_betonkern_error2.lst>> 
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