[esp-r] Re: Slabs // water flow divergers/convergers // Control functions // air&water temperature source

[Udo Schuster]

Hello all,

Thank you very much for your inputs. I tested them out and here are the results:


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Proceedings
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I used
- boiler (ref no. 11, non-condensing, 1 node)
- water flow diverger (ref no. 46, 3 nodes)
- 2 slabs (ref no. 56, 1 node)
- water flow converger (ref no. 47, 1 node)
- pump (ref no. 15, 1 node)

and connected them like this:
--> you need to design the loop correctly so that the fluid exiting the source goes to slab1 and slab2 using a diverging junction, then collect the outlet water from both slabs using a converging junction (each junction end links to the outlet of slab), then the total water flow leaving the junction enters the pump then the source.


 
I applied the plant to one cubical thermal zone.
In order to link each slab to a surface in the plant network menue, I had to create two zone control functions. However, I could link only one of them to the zone.

The plant control function, I set up like this: 

For the control of the radiant slab you will specifying, for plant control, that you're controlling the flow to the slab based on the temperature sensed in the zone. It seems then possible to specify more than one slab for the same zone.


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Results
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I could run simulations succesfully, though while setting up simulation, I got a MZPMXT warning for the water flow diverger, node 3 (the inlet, I suppose):"is a connector with no exit connection" 
Does this matter?




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Use of air & water temperature source
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However, I would like to use the air & water temperature source, ref no. 24. In the past, we could apply measured data from an ascii-file to it succesfully, but only for plants including 1 slab, 1 pump, 1 source. The air node had been short-circuited.

When I apply the source to the plant from above, I get the following message:
 
  MZPADJ: reverse mass flow connection  4
  MZPADJ: 1th phase mass flow reset to zero
cmaslv: Backsubstitution phase.
         Fatal error :Zero diagonal in row 5


connection 4 is: slab2 sending, water flow converger receiving





Using one cubical zone with two plants, each 1 slab, 1 pump, 1 source  produces:


  MZPADJ: reverse mass flow connection  6
  MZPADJ: 1th phase mass flow reset to zero
  MZPADJ: reverse mass flow connection  8
  MZPADJ: 1th phase mass flow reset to zero
  MZPADJ: reverse mass flow connection  6
  MZPADJ: 1th phase mass flow reset to zero
  MZPADJ: reverse mass flow connection  8
  MZPADJ: 1th phase mass flow reset to zero
 cmaslv: Backsubstitution phase.
         Fatal error :Zero diagonal in row 5



connection 6 is: source2 sending, pump2 receiving

connection 8 is: slab2 sending, source2 receiving






Kind regards,
Udo




 








-- 
Dipl.-Ing. (FH) Udo Schuster
Dep. Thermal Systems and Buildings
Fraunhofer-Institut für Solare Energiesysteme ISE
Heidenhofstrasse 2, 79110 Freiburg, Germany
Phone: +49(0)761/4588-5309 Fax: +49(0)761/4588-9000
udo.schuster at ise.fraunhofer.de
http://www.ise.fraunhofer.de