[TRNSYS-users] Slow model at boiler pressure of 10000kPa

David BRADLEY d.bradley at tess-inc.com
Wed Aug 14 09:49:42 PDT 2019


Amir,

   Which v18 release is it? I tried with 18.00.0019 and 18.01.0000 and 
the simulations solves quickly. You can check the release number by 
opening the file trnsys.ini using a text editor such as Notepad. The 
steam quality is set to that odd value because the liquid is subcooled 
at your conditions and therefore the quality is undefined.

kind regards,

  David


On 08/13/2019 18:07, Amir Nashed via TRNSYS-users wrote:
>
> Hi Jeff
>
> Thanks for the email
>
> I am using TRNSYS 18
>
> If you want to replicate the issue, simply useType58 and put 
> P=10000kPa and h=940 kJ/kg and you will get both issues: 1- super slow 
> simulation 2- odd steam quality value of -1.5e38
>
> Thanks
>
> *Best Regards,*
>
> **
>
> *Amir Nashed, PhD***
>
> Energy Engineer
>
> Estate Management
>
> UNSW SYDNEY NSW 2052 AUSTRALIA
>
> E: a.nashed at unsw.edu.au <mailto:a.nashed at unsw.edu.au>
>
> T: +61 2 9385 3401
>
> M: +61 4 0597 9282
>
> W: www.estate.unsw.edu.au <http://www.estate.unsw.edu.au/>
>
> CRICOS Provider Code 00098G
>
> cid:image001.png at 01D2758A.1DD460C0 <http://www.unsw.edu.au/>
>
> *From:*Jeff Thornton <thornton at tess-inc.com>
> *Sent:* Wednesday, 14 August 2019 1:25 AM
> *To:* TRNSYS users mailing list at OneBuilding.org 
> <trnsys-users at lists.onebuilding.org>
> *Cc:* Amir Nashed <a.nashed at unsw.edu.au>
> *Subject:* Re: [TRNSYS-users] Slow model at boiler pressure of 10000kPa
>
> Amir,
>
> Which version of TRNSYS are you using?  I know we identified and fixed 
> an issue within the steam properties subroutine a few months back that 
> might be the cause for your issue.
>
> Jeff - TESS
>
> Sent from my iPhone
>
>
> On Aug 12, 2019, at 6:56 PM, Amir Nashed via TRNSYS-users 
> <trnsys-users at lists.onebuilding.org 
> <mailto:trnsys-users at lists.onebuilding.org>> wrote:
>
>     Dear TRNSYS users
>
>     For some reason all steam components at P=100 Bar (10,000 kPa) go
>     very slow, whether it is a preheater, condensate pump..etc
>
>     The issue is not with the model, as I isolated the components, for
>     example simulated type609 by itself and still did not work. . I
>     believe the reason is the the Steam_Properties() subroutine as
>     when I tried to use Type58 just by itself at the same steam
>     properties, the same issues occurred. When I reduce the pressure
>     to 9300 kPa, it works fine.
>
>     Inputs:
>
>     <image002.jpg>
>
>     Does anyone know how to solve that?
>
>     I can change the pressure, but I believe 100 bars for boiler
>     pressure is pretty standard
>
>     *Best Regards,*
>
>     **
>
>     *Amir Nashed, PhD*
>
>     Energy Engineer
>
>     Estate Management
>
>     UNSW SYDNEY NSW 2052 AUSTRALIA
>
>     E: a.nashed at unsw.edu.au<mailto:a.nashed at unsw.edu.au>
>
>     T: +61 2 9385 3401
>
>     M: +61 4 0597 9282
>
>     W: www.estate.unsw.edu.au<http://www.estate.unsw.edu.au/>
>
>     CRICOS Provider Code 00098G
>
>     <image001.png><http://www.unsw.edu.au/>
>
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-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
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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