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

王洋 wanghongyang1767 at gmail.com
Wed Oct 20 06:16:11 PDT 2010


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 at cae.wisc.edu>

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>   1. discrete time step and the simulation time step
>      (=?GB2312?B?zfXR8w==?=)
>
>
> ---------- 已转发邮件 ----------
> From: 王洋 <wanghongyang1767 at gmail.com>
> To: trnsys-users at 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 at 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 at 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 at cae.wisc.edu
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>>> 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
>>> than "Re: Contents of TRNSYS-users digest..."
>>>
>>> Today's Topics:
>>>
>>>   1. Re: Trigeneration simulation: printing or convergence problem
>>>      ? (David BRADLEY)
>>>   2. fresnel Collector (farah.gammoh at mirroxx.com)
>>>   3. UNSUSCRIBE (info at 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 at tess-inc.com>
>>> To: "wim.vansteenkiste at ugent.be" <Wim.Vansteenkiste at 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 at 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.
>>>>
>>>>
>>>> _______________________________________________
>>>> 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
>>> d.bradley at tess-inc.com
>>>
>>> http://www.tess-inc.com
>>> http://www.trnsys.com
>>>
>>>
>>>
>>>
>>> ---------- 已转发邮件 ----------
>>> From: "farah.gammoh at mirroxx.com" <farah.gammoh at mirroxx.com>
>>> To: "TRNSYS-users at cae.wisc.edu" <TRNSYS-users at 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 at aacarchitecture.be" <info at aacarchitecture.be>
>>> To: TRNSYS-users at cae.wisc.edu
>>> Date: Mon, 18 Oct 2010 21:55:09 +0200
>>> Subject: [TRNSYS-users] UNSUSCRIBE
>>> Please Unsuscribe following adresses:
>>> aac at win.be
>>> info at aac-archi.be
>>> info at aacarchitecture.be
>>>
>>> Thanks
>>>
>>>
>>>
>>> Marc Vande Perre
>>> mv at aacarchitecture.be
>>>
>>> n.v. AAC Architecture s.a.
>>>
>>>
>>>
>>> ---------- 已转发邮件 ----------
>>> From: Dimas Firmanda Al Riza <dimasfirmanda at gmail.com>
>>> To: hotline <hotline at 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 at 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 at 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 at gmail.com]
>>>>> *Gesendet:* Montag, 18. Oktober 2010 02:33
>>>>> *An:* trnsys-users at 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
>>>>>
>>>>>
>>>>
>>>
>>> _______________________________________________
>>> TRNSYS-users mailing list
>>> TRNSYS-users at cae.wisc.edu
>>> https://www-old.cae.wisc.edu/mailman/listinfo/trnsys-users
>>>
>>>
>>
>
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