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[TRNSYS-users] discrete time step and the simulation time step

Dear all,
 
I have some questions to ask you:
 
To Type 22: The manual said this controller can be used to model a real feedback controller (e.g. PID) that would adapt its control signal continuously or use a discrete time step much shorter than the simulation time step in TRNSYS.
 
What's meaning of  a discrete time step and  the simulation time step ?
 
Do you know how many minutes this Type 22's discrete time step is ?  And what's the min. minutes this Type 22's discrete time step is ?
 
What's the min. simulation time step  in TRNSYS?
 
many thanks!
 
br.
 
wang

2010/10/19 <trnsys-users-request@cae.wisc.edu>
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Today's Topics:

  1. discrete time step and the simulation time step
     (=?GB2312?B?zfXR8w==?=)


---------- 已转发邮件 ----------
From: 王洋 <wanghongyang1767@gmail.com>
To: trnsys-users@cae.wisc.edu
Date: Tue, 19 Oct 2010 22:25:59 +0200
Subject: [TRNSYS-users] discrete time step and the simulation time step
Dear all,
 
I have some questions to ask you:
 
To Type 22: The manual said this controller can be used to model a real feedback controller (e.g. PID) that would adapt its control signal continuously or use a discrete time step much shorter than the simulation time step in TRNSYS.
 
What's meaning of  a discrete time step and  the simulation time step ?
 
Do you know how many minutes this Type 22's discrete time step is ?  And what's the min. minutes this Type 22's discrete time step is ?
 
What's the min. simulation time step  in TRNSYS?
 
many thanks!
 
br.
 
wang


2010/10/19 王洋 <wanghongyang1767@gmail.com>
Dear all,
 
I have some questions to ask you:
 
To Type 22: The manual said this controller can be used to model a real feedback controller (e.g. PID) that would adapt its control signal continuously or use a discrete time step much shorter than the simulation time step in TRNSYS.
 
What's meaning of  a discrete time step and  the simulation time step ?
 
Do you know how many minutes this Type 22's discrete time step is ?  And what's the min. minutes this Type 22's discrete time step is ?
 
What's the min. simulation time step  in TRNSYS?
 
many thanks!
 
br.
 
wang

2010/10/19 <trnsys-users-request@cae.wisc.edu>
Send TRNSYS-users mailing list submissions to
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or, via email, send a message with subject or body 'help' to
       trnsys-users-request@cae.wisc.edu

You can reach the person managing the list at
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When replying, please edit your Subject line so it is more specific
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Today's Topics:

  1. Re: Trigeneration simulation: printing or convergence problem
     ? (David BRADLEY)
  2. fresnel Collector (farah.gammoh@mirroxx.com)
  3. UNSUSCRIBE (info@aacarchitecture.be)
  4. Re: type 109 with 5 minutes time step (Dimas Firmanda Al Riza)


---------- 已转发邮件 ----------
From: David BRADLEY <d.bradley@tess-inc.com>
To: "wim.vansteenkiste@ugent.be" <Wim.Vansteenkiste@UGent.be>
Date: Mon, 18 Oct 2010 12:45:26 -0500
Subject: Re: [TRNSYS-users] Trigeneration simulation: printing or convergence problem ?
Wim,
asterisks in the output file are often an indication that the format statement for what was being printed was not correct. I am not sure what component you are using for your output device but if it is either Type25 or Type46 make sure that you are using an "unformatted" mode.
Regards,
David


On 10/16/2010 12:45, wim.vansteenkiste@ugent.be wrote:
Dear TRNSYS-users,

I'm only been using TRNSYS for 2 months, so I'm quite new at it.

I'm simulating a trigeneration system: a custom made gas engine model
combined with an absorption chiller.

TRNSYS doesn't indicate convergence problems after simulating.
Based on plotted values, the simulation seems satisfactory as well.

I print the output values of every component. When I view these output
values, there seems to be a problem:

A lot of values aren't printed. Instead of the value,
"***************" appears. This happens for almost every mass flow as
well as for the energy rates in the absorption chiller. The strange
thing is that the values can be plotted, only when I print them I get
this problem. Temperatures and other values are printed correctly.

Do you have an idea of what could be the cause of this problem?

Thanks in advance,

Wim.


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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@tess-inc.com

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




---------- 已转发邮件 ----------
From: "farah.gammoh@mirroxx.com" <farah.gammoh@mirroxx.com>
To: "TRNSYS-users@cae.wisc.edu" <TRNSYS-users@cae.wisc.edu>
Date: Mon, 18 Oct 2010 17:58:59 +0200
Subject: [TRNSYS-users] fresnel Collector
Hello,
is there a way to simulate a fresnel collector field using once of the STE models?

thanks and best regards,
Farah



---------- 已转发邮件 ----------
From: "info@aacarchitecture.be" <info@aacarchitecture.be>
To: TRNSYS-users@cae.wisc.edu
Date: Mon, 18 Oct 2010 21:55:09 +0200
Subject: [TRNSYS-users] UNSUSCRIBE
Please Unsuscribe following adresses:

Thanks



Marc Vande Perre         

n.v. AAC Architecture s.a.            



---------- 已转发邮件 ----------
From: Dimas Firmanda Al Riza <dimasfirmanda@gmail.com>
To: hotline <hotline@transsolar.com>
Date: Tue, 19 Oct 2010 10:32:47 +0800
Subject: Re: [TRNSYS-users] type 109 with 5 minutes time step
Dear all, 

I have problem again with simulation time step,

I use Type 9 data reader, with 5 minutes time step data,
1. How to write the simulation start time in (type 9) if I simulate it together with weather data in June (in type 109)?
2. I did a test with my data file, I connect type 9 with online plotter, I put data in type 9 like the note bellow,
    and I set simulation start time 0 stop time is 120, when I set simulation time step to 5 minutes the simulation error, 
    but when simulation time step to 2.5 minutes, the simulation run, 
    Do I need to set simulation time step in control card below 5 minutes if the data is in 5 minutes interval?
3. I run my complete simulation, with type 9 and type 109, I set simulation time step to 2.5 minutes, i run simulation for a month,
    but the simulation run only for several hour and then stopped, I got some warning:

simulation log:
Radiation while sun is down found    1 times (What is this?)
 only the first 10 warnings with data info are printed 
 check: - Time of first data line
        - Longitude and Latitude
 REMARK: these radiation values are set to ZERO !

 ***** WARNING FROM UNIT   2 TYPE 109 DATA READER
 RADIATION DATA READ IN FROM FILE ==>Weather UTP - June 1-30 (5 min).109
 AT LINE #    2 ARE SET TO ZERO SINCE SUN IS DOWN, ORIGINAL VALUE:   28.91 W/m²

 ***** WARNING FROM UNIT   2 TYPE 109 DATA READER
 RADIATION DATA READ IN FROM FILE ==>Weather UTP - June 1-30 (5 min).109
 AT LINE #    3 ARE SET TO ZERO SINCE SUN IS DOWN, ORIGINAL VALUE:   28.91 W/m²


Simulation lst file:
*** Warning at time       :        61.416667
    Generated by Unit     : Not applicable or not available
    Generated by Type     : Not applicable or not available
    TRNSYS Message    441 : The inputs to the listed units have not converged at this timestep. The values at the last iteration will be used and the simulation will proceed.
    Reported information  : UNITS: 4  10  11  17
 
*** Fatal Error at time   :        61.416667
    Generated by Unit     : Not applicable or not available
    Generated by Type     : Not applicable or not available
    TRNSYS Message    450 : The maximum number of warnings allowed per simulation has been exceeded. Please fix these warnings or increase the limit on the number of warnings allowed per simulation (LIMITS command)
    Reported information  : Not available
 
*** Warning at time       :        61.416667
    Generated by Unit     : Not applicable or not available
    Generated by Type     : Not applicable or not available
    TRNSYS Message    442 : The listed differential equations have not converged at this timestep. The values at the last iteration will be used and the simulation will proceed.
    Reported information  : DIFFERENTIAL EQUATIONS: 1


Please help me to solve this problem, thank you very much

Best Regards,

Dimas

______________________________________________________________________________________________________________
Note:
Data in .txt file for type 9 (time interval 5 minutes):

25.07
40.18
42.77
0.00
27.82
27.91
15.28
46.04
30.81
54.12
33.61
54.50
49.43
54.36
85.52
57.23
83.40
83.58
105.23
98.98
96.83
108.26
113.00
121.50


 

On Mon, Oct 18, 2010 at 3:59 PM, Dimas Firmanda Al Riza <dimasfirmanda@gmail.com> wrote:
I have adjusted it by now, and it works! thanks a lot! 
I adjust it like below

<interval> 0.08333   ! Data file time interval between consecutive lines
<firsttime> 0.08333       ! Time corresponding to first data line (hours)

-dimas-


On Mon, Oct 18, 2010 at 3:28 PM, hotline <hotline@transsolar.com> wrote:
Dimas,
 
did you also adjust the "Time corresponding to first data line" ?
 
<firsttime> 1          ! Time corresponding to first data line (hours)
In addition, you need to set the simulation time step to 5 minutes.
 
Marion
 
 

   Von: Dimas Firmanda Al Riza [mailto:dimasfirmanda@gmail.com]
Gesendet: Montag, 18. Oktober 2010 02:33
An: trnsys-users@cae.wisc.edu
Betreff: [TRNSYS-users] type 109 with 5 minutes time step

Dear all,


I have 5 minutes time step weather data, 
How to conduct simulation with 5 minutes time step using type 109, 
do I need to change something in the .109 data file?
I've try to just change the data in .109 file from 1 hour time step with my 5 minutes time step data
but when I run simulation with 5 minutes time step the results become weird,
Thank you very much

Regards,

Dimas Firmanda A.
MSc student
Mechanical Engineering Department
Universiti Teknologi PETRONAS




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TRNSYS-users@cae.wisc.edu
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