[TRNSYS-users] Storage tank - input inconsistency when 10min interval

David BRADLEY d.bradley at tess-inc.com
Mon Sep 24 07:29:37 PDT 2012


Michal,
   It makes TRNSYS happy if you are able to write time steps and data 
intervals as the quotient of two integers. I would recommend using an 
equation like:

EQUATIONS 1
DELT = 10/60

then you can use the variable DELT for both your simulation timestep and 
your data interval.

Best,
  David


On 9/24/2012 06:20, Michal Klimas wrote:
> Dear David,
>
> Your advice helped in a way that I have changed in type 9:
> -not to interpolate water flow
> -set "0" for an average value over the data time interval.
>
> Now it works fine. Thank you !
>
> I also tried considering the TRNSYS equation, but if a TIMESTEP=10 min and data read interval is the same, in your opinion, what the equation should look like ?
>
> Best regards
> Michal Klimas
>
>
>
> ----- Original Message -----
> From: "David BRADLEY" <d.bradley at tess-inc.com>
> To: "Michał Klimas" <michal.klimas at put.poznan.pl>
> Cc: trnsys-users at cae.wisc.edu
> Sent: Friday, 21 September, 2012 6:50:06 PM
> Subject: Re: [TRNSYS-users] Storage tank - input inconsistency when 10min interval
>
> Michal,
> There may not really be a problem here. TRNSYS outputs are averages over each timestep and inputs are assumed to be constant over a timestep. As a result the inputs to Type534 are assumed to be the average flow rate over your 10 minute period. Type9 also gives you various options for what kind of data you are giving it (averages over the timestep, instantaneous values at the end of the timestep, etc.). If you have integrated flows over the 10 minute periods, you can use an equation to back out what the average flow rate was over the period.
> Kind regards,
> David
>
>
>
> On 9/19/2012 09:26, Michał Klimas wrote:
>
>
>
>
>
> Dear All,
>
>
>
> I’m trying to simulate water flow through storage tank ( type 534). I’ve got real measurements of water temp. and flow with 10min interval (using type 9e) but units of tank inputs can only be kg/s or kg/h and so on.
>
> My simulation TIMESTEP must be 10 min (1/6 as an equation) so I cannot interpolate any data.
>
>
>
> Do you have any idea how to solve this problem ?
>
>
>
>
>
> best regards
>
> Michal Klimas
>
>
>
>
>
> _______________________________________________
> TRNSYS-users mailing list TRNSYS-users at cae.wisc.edu https://mailman.cae.wisc.edu/listinfo/trnsys-users

-- 
***************************
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

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