[TRNSYS-users] Type60 tank problem

[David BRADLEY]

Brian,
   Technically, there is nothing wrong with the way that you implemented 
your inputs to Type60. The negative flow rate error is showing up 
because of the order in which the components are called (they are called 
in the same order in which they appear in the input file). For 
reference, your input connections are:

pump (Unit 6 - Type114) --> Flow Rate at Outlet 2 (Unit 4 - Type60)
pipe (Unit15 - Type32b) --> Flow Rate at Inlet 2 (Unit 4 - Type60)

At one of the iterations in the first timestep (before convergence has 
been reached) the pump changes state and the tank gets called before the 
pipe component does so as a result, the flow rate out of the pump has 
changed but the flow rate out of the pipe hasn't yet when the tank model 
is called.

The fix is pretty simple: you can just revise your connections as follows:

pipe (Unit15 - Type32b) --> Flow Rate at Outlet 2 (Unit 4 - Type60)
pipe (Unit15 - Type32b) --> Flow Rate at Inlet 2 (Unit 4 - Type60)

best,
  David


On 2/17/2013 22:25, Brian Raichle wrote:
> Hello,
> I'm using a Type60c tank in a simple direct solar water heating model. 
> I get the "negative flow" error. The input/outputs are defined as:
> inlet 1 flow: mains flow             outlet 1 flow: -2
> inlet 2 flow: solar pump flow      outlet 2 flow: solar pump flow
> Not sure where else to look.  Any thoughts?
> Thanks,
> Brian
>
> -- 
> Brian Raichle
> Department of Technology and Environmental Design
> Appalachian State University
>
>
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> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu
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-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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