[TRNSYS-users] Fwd: Strange Opening Factor (OF) of Window
David BRADLEY
d.bradley at tess-inc.com
Wed Oct 5 13:52:21 PDT 2011
Wang,
I apologize but I don't know the answer to your questions. I am not
familiar with TRNFlow/COMIS; I use the CONTAM/Type97 option for my work
on combined thermal/airflow studies.
Kind regards,
David
On 10/5/2011 14:51, 王洋 wrote:
>
>
> Dear Mr. Bradley
>
> Many thanks for your patient reply!
>
> 1) Firstly, I only defined one Thermal Airnode in one zone, two
> External nodes, two Large opening. So I guess the reason is not the
> first you said. But I found the definition of Large opening,
> especially For Closed Opening: flow coefficient Cs per m crack is
> 0.0001 kg/s/m at 1 Pa. Moreover, I found indeed the hot air escapes
> from the zone about 2.42 kg/h after I set the OF as 0 (from 6 pm to 8
> am). But when I set Cs as 0 kg/s/m at 1 Pa, moreover, I defined wind
> pressure coefficients Cp as 0 for 2 external nodes, there is still a
> WEIRD thing: the CO2% still decreases, however, the hot air escapes
> from the zone about 0.65 kg/h (which is almost the same from 6 pm to 8
> am) after I set the OF as 0. I guess COMIS maybe still has an default
> although OF is 0 and Cs is 0 kg/s/m. But I indeed need CO2% as a
> constant after OF is 0.
>
> 2) For your second reason, I checked the COMIS documentation. I found
> Air Flow calculationis a steady state simulation, however, the
> Pollutant Transport is calculated with a dynamic model. Whether CO2%
> decreases due to this reason i.e. COMIS is trying to predict CO2%,
> when OF is 0 (Air Flow calculation), however, CO2% is still calculated
> by COMIS (after OF is 0 during this simulation step). But like 1), the
> hot air escapes from the zone about 0.65 kg/h (which is almost the
> same from 6 pm to 8 am) after I set the OF as 0. Hence, I think this
> reason 2) is still not reasonable. Moreover, I found although TRNFlow
> ‘s engine is COMIS, for some issues, the manuals of both of them COMIS
> and TRNFlow are still not clear and relative completely. Could you
> introduce other references or COMIS (EMPA) guys to give me an exact
> answer for this WEIRD thing? Because it troubles me for a long time. I
> need find the stable PID parametersto control OF which can keep CO2%
> under or at the set-point 1000 ppm. Until now, I found the stable PID
> parameters for one day, but due to CO2% decreases after OF is 0 from 6
> pm. Hence, the stable PID parameters for one day don’t work for next
> day from 8 am. Please see the ATTACHED. The stable PID parameters
> maybe are too large for next day’s CO2%.
>
> 3) For your third reason, I only defined 2 Large opening not including
> fans and ducts etc. by TRNFlow, maybe you think they two large opening
> are a true Mechanical ventilation system?
>
> Many thanks in advance!
>
> Br.
>
> wang
>
>
>
> 2011/9/30 David BRADLEY <d.bradley at tess-inc.com
> <mailto:d.bradley at tess-inc.com>>
>
> Wang,
> I will preface this by mentioning that I am not an expert in the
> TRNFlow part of Type56.
>
> It is a little hard to know what is going on without knowing
> anything about the building. However, if you have multiple zones
> in the building, I imagine that there would be some air mixing
> going on between zones due to internal temperature and height
> differences and the CO2 concentration would decrease in one zone
> while increasing in another.
>
> I would also recommend looking at the COMIS documentation (COMIS
> is the engine that underlies TRNFlow) to see whether its
> algorithms are trying to predict CO2 concentration at a particular
> point in the space (like we do in Type56 for comfort calculations
> at a particular point in a zone) or whether it is assuming a fully
> mixed zone as far as the CO2 level is concerned. If COMIS is
> calculating concentration at a point and the air continues to mix
> after your opening factor has gone to zero then that might explain
> the decrease.
>
> Lastly, your mechanical ventilation system might have something
> to do with the decrease; If you are actively supplying air to the
> space after the opening factor is zero and if the mechanical
> ventilation system has some outdoor air associated with it then
> that also would explain the decrease in CO2 level.
>
> Regards,
> David
>
>
>
> On 9/30/2011 08:47, 王洋 wrote:
>> Dear all,
>> I simulated CO2 concentration changes using TRNFlow. But
>> there is a STRANGE phenomenon. There are 2 occupants from 8am to
>> 6 pm, CO2% is controlled by PID controller which controls Opening
>> Factor (OF) of window at the set-point 1000 ppm. From 6 pm, there
>> are no occupants, OF is 0, there is no infiltration in TRNBuild
>> (Certainly, infiltration in TRNBuild indeed will inactivate when
>> couping TRNFlow based on TRNFlow Manual). However, from 6 pm,
>> CO2% begins to decrease. It's extremely strange!
>> Which relative expert can expain that? Or give me some advices
>> for that? I am puzzled for a long time.
>> Many thanks in advance!
>> br
>> wang
>>
>> 2011/9/30 <trnsys-users-request at cae.wisc.edu
>> <mailto:trnsys-users-request at cae.wisc.edu>>
>>
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>> Today's Topics:
>>
>> 1. Using Excel as Load Profile (Pei Ru Chao)
>> 2. TRNSYS error 300 (torres.carlos-moises at lte.ireq.ca
>> <mailto:torres.carlos-moises at lte.ireq.ca>)
>> 3. Direct expansion solar collector (Mohamad Azly Abd Aziz
>> (Ir))
>> 4. simulation studio crash when updating project (Antoine
>> Gautier)
>>
>>
>> ---------- 已转发邮件 ----------
>> From: Pei Ru Chao <simplica1 at hotmail.com
>> <mailto:simplica1 at hotmail.com>>
>> To: TRNSYS <trnsys-users at cae.wisc.edu
>> <mailto:trnsys-users at cae.wisc.edu>>
>> Date: Fri, 30 Sep 2011 16:31:53 +1000
>> Subject: [TRNSYS-users] Using Excel as Load Profile
>> Hi all,
>>
>> As a newbie I am wondering how to use Excel for load profile
>> input. Can anyone point me in the right direction as to how
>> to use a Data Reader to do this? For example, can the Data
>> Reader read 10920 rows of data? In 9a for example, Parameter
>> 2 asks how many values of input to read and the maximum is
>> only 98?
>>
>> Thanks
>>
>> Pei
>>
>>
>>
>>
>> ---------- 已转发邮件 ----------
>> From: <torres.carlos-moises at lte.ireq.ca
>> <mailto:torres.carlos-moises at lte.ireq.ca>>
>> To: <trnsys-users at cae.wisc.edu
>> <mailto:trnsys-users at cae.wisc.edu>>
>> Date: Thu, 29 Sep 2011 15:50:36 -0400
>> Subject: [TRNSYS-users] TRNSYS error 300
>> Dear all,
>> Whenever I ry to run a type 56 simulation in TRNSED I am
>> given the following error even though the same program runned
>> perfectly in TRNEdit
>> ***** ERROR ***** TRNSYS ERROR # 300
>> UNABLE TO START PROGRAM IN CALLPROGRAM UTILITY
>> PLEASE CHECK PATH AND PROGRAM NAME, THIS MAY BE A PROBLEM IN
>> TYPE 66
>>
>> *** Fatal Error at time : 0.000000
>> Generated by Unit : Not applicable or not available
>> Generated by Type : Not applicable or not available
>> TRNSYS Message 300 : The TRNSYS Program attempted to
>> evaluate an EQUATION that raised a negative number to a
>> non-integer value. Please check the EQUATION formulation and
>> re-run the simulation
>> Reported information : Not available
>> the message is not very helpfull and I don't even use Type 66
>> in my simulation and I checked all my equations and nothing
>> obvious comes to view.
>> Is there any known solution to this problem? If need be I can
>> send you the files im using.
>> Thank you
>> Carlos Torres
>> Stagiaire universitaire
>> Laboratoire des technologies de l'énergie (LTE)
>>
>>
>> ---------- 已转发邮件 ----------
>> From: "Mohamad Azly Abd Aziz (Ir)" <AZLY at jkr.gov.my
>> <mailto:AZLY at jkr.gov.my>>
>> To: "trnsys-users at cae.wisc.edu
>> <mailto:trnsys-users at cae.wisc.edu>"
>> <trnsys-users at cae.wisc.edu <mailto:trnsys-users at cae.wisc.edu>>
>> Date: Fri, 30 Sep 2011 04:36:25 -0700
>> Subject: [TRNSYS-users] Direct expansion solar collector
>>
>> Hi
>>
>> I wonder whether someone has come-out with heat pump type
>> with direct expansion solar collector/evaporator?.
>>
>> Regards
>>
>> Azly
>>
>>
>>
>> ---------- 已转发邮件 ----------
>> From: "Antoine Gautier" <antoine.gautier at solamen.fr
>> <mailto:antoine.gautier at solamen.fr>>
>> To: <trnsys-users at cae.wisc.edu
>> <mailto:trnsys-users at cae.wisc.edu>>
>> Date: Fri, 30 Sep 2011 13:48:10 +0200
>> Subject: [TRNSYS-users] simulation studio crash when updating
>> project
>>
>> Dear all
>>
>> I cannot update my project any more without crashing
>> simulation studio (*.tpf and *.b17 in attachment).
>>
>> Is there another way to update the input list for Type56 so
>> that I can keep on working?
>>
>> Thanks a lot for your help.
>>
>> Best regards
>>
>> --
>>
>> Antoine Gautier
>> Solamen
>> +33 6 98 78 56 46 <tel:%2B33%206%2098%2078%2056%2046>
>>
>> antoine.gautier at solamen.fr <http://lamen.fr/>
>>
>>
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>>
>>
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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 <tel:%2B1.608.274.2577>
> F:+1.608.278.1475 <tel:%2B1.608.278.1475>
> d.bradley at tess-inc.com <mailto:d.bradley at tess-inc.com>
>
> http://www.tess-inc.com <http://www.tess-inc.com/>
> http://www.trnsys.com <http://www.trnsys.com/>
>
>
>
--
***************************
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
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