[TRNSYS-users] Problem with Type 55: Periodic Integrator - reset time

[Eric Wilson]

David,

Setting parameter 2 to 0 did not fix the problem.  I discovered that
the integrator will cycle correctly if my simulation start hour is
less than 24 (and in general, if the simulation start hour is less
than the cycle interval). Compare the attached "start23.dck" to
"start24.dck".

I found that you can get around this by setting the relative start
time so that: Parameter2 + Parameter 5 > SimulationStartTime. For
example, if you want to start the simulation at hour 48, and your
reset interval (P5) is 24, setting the relative start hour (P2) to 25
or greater will make it repeat properly, although not always starting
at hour 48. For my simulation that starts at hour 1512, the following
parameters make it work properly, including starting integrating at
hour 1512:

    1          ! 15 Integrate or sum input-3
    1512     ! 16 Relative starting hour for input-3
    24        ! 17 Duration for input-3
    24        ! 18 Cycle repeat time for input-3
    24        ! 19 Reset time for input-3
    start     ! 20 Absolute starting hour for input-3
    stop     ! 21 Absolute stopping hour for input -3

I don't quite understand why it works, but it does!

Thanks for your advice,
Eric

On Wed, Jul 21, 2010 at 8:48 AM, David Bradley <bradley at tess-inc.com> wrote:
>
> Eric,
>  I think your parameter set has some overlapping intervals.
>
> - parameter 5 determines when the input resets to zero (in your case, it is resetting daily at midnight)
> - parameter 2 determines when in that 24 hour period the integrator starts paying attention (by setting it to 1, it is ignoring the fist hour in the 24 hour period)
> - parameter 3 determines how long the input should be evaluated (by setting it to 24 and starting at 1, you're progressively evaluating one hour longer than your reset time each day of the simulation (1+24 = 25...)
>
> try setting parameter 2 to 0 and see if that cures the problem. I'm not sure why it is behaving properly when you start a new project.
> Best,
>  David
>
>
> On 7/20/2010 20:25, Eric Wilson wrote:
>
> Hi all,
>
> In a project of mine, none of my Type 55 integrators reset after a cycle as they should (they continue to integrate until the end of the simulation), unless they are set to a monthly cycle with a value of -1. In a blank new project, they work fine.  Has anyone encountered this problem?
>
> * Model "Type55" (Type 55)
> *
>
> UNIT 78 TYPE 55     Type55
> *$UNIT_NAME Type55
> *$MODEL .\Utility\Integrators\Periodic Integrator\Type55.tmf
> *$POSITION 815 50
> *$LAYER Main #
> PARAMETERS 7
> 1        ! 1 Integrate or sum input
> 1.0        ! 2 Relative starting hour for input
> 24        ! 3 Duration for input
> 24        ! 4 Cycle repeat time for input
> 24        ! 5 Reset time for input
> start        ! 6 Absolute starting hour for input
> stop        ! 7 Absolute stopping hour for input
> INPUTS 1
> supply_diam        ! HVAC_Inputs:supply_diam ->Input
> *** INITIAL INPUT VALUES
> 0.
>
> Many thanks,
> Eric
>
> --
> Eric Wilson
> M.S. Candidate, Building Systems Program
> Dept of Civil, Env., and Arch. Engineering
> University of Colorado at Boulder
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu
> https://www-old.cae.wisc.edu/mailman/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
> bradley at tess-inc.com
>
> http://www.tess-inc.com
> http://www.trnsys.com
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