[TRNSYS-users] Negative value of Radiation in TRNSYS 16

王洋 wanghongyang1767 at gmail.com
Mon Oct 29 03:17:16 PDT 2012
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dear all,

I would like to ask you a question about solar radiation. I met an error as
follows. I used Type 9e to import our own solar radiation data whose unit
is W/m2, meantime, I also used an Equation to transfer its unit to kJ/hm2
(i.e. xx*3.6) and used ABS to ensure its value as Positive connected with
Type 16a (Radiation processors). But it still appears the error as follows.
Please tell me how could I solve this problem? E.g. use which Type I should
use more easily and correctly and what are the detailed processes to import
our own solar radiation to connect with Type 56?

*** Fatal Error at time   :      3820.800000
    Generated by Unit     :    56
    Generated by Type     :    56
    Message               : Negative value of solar radiation for
5orientation encountered


Many thanks in advance!
Br.
wang


2012/10/26 王洋 <wanghongyang1767 at gmail.com>

> dear all,
>
> I would like to ask you a question about solar radiation. I met an error
> as follows. I used Type 9e to import our own solar radiation data whose
> unit is W/m2, meantime, I also used an Equation to transfer its unit to
> kJ/hm2 (i.e. xx*3.6) and used ABS to ensure its value as Positive. But it
> still appears the error as follows. Please tell me how could I solve this
> problem? E.g. use which Type I should use more easily and what are the
> detailed processes to import our own solar radiation to connect with Type
> 56?
>
> *** Fatal Error at time   :      3820.800000
>     Generated by Unit     :    56
>     Generated by Type     :    56
>     Message               : Negative value of solar radiation for
> 5orientation encountered
>
>
> Many thanks in advance!
> Br.
> wang
>
> 2012/10/26 <trnsys-users-request at cae.wisc.edu>
>
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>> Today's Topics:
>>
>>    1. Max. time points of Type 14 in TRNSYS 16 (??)
>>
>>
>> ---------- 已转发邮件 ----------
>> From: 王洋 <wanghongyang1767 at gmail.com>
>> To: trnsys-users at cae.wisc.edu
>> Cc:
>> Date: Fri, 26 Oct 2012 11:27:38 +0200
>> Subject: [TRNSYS-users] Max. time points of Type 14 in TRNSYS 16
>> Dear all,
>>
>> I'd like to ask you whether or not max. time points of Type 14 is only 20
>> in TRNSYS 16?
>> If I need more than 20 points, how could I solve this problem?
>>
>> Many thanks in advance!
>>
>> Br
>>
>> wang
>>
>> 2012/10/26 <trnsys-users-request at cae.wisc.edu>
>>
>>> Send TRNSYS-users mailing list submissions to
>>>         trnsys-users at cae.wisc.edu
>>>
>>> To subscribe or unsubscribe via the World Wide Web, visit
>>>         https://mailman.cae.wisc.edu/listinfo/trnsys-users
>>> or, via email, send a message with subject or body 'help' to
>>>         trnsys-users-request at cae.wisc.edu
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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: Type energy balance (David BRADLEY)
>>>    2. Re: Type energy balance (Micha?l Kummert)
>>>
>>>
>>> ---------- 已转发邮件 ----------
>>> From: David BRADLEY <d.bradley at tess-inc.com>
>>> To: PARTENAY Vincent <vincent.partenay at cstb.fr>
>>> Cc: "trnsys-users at cae.wisc.edu" <trnsys-users at cae.wisc.edu>
>>> Date: Thu, 25 Oct 2012 16:34:28 -0500
>>> Subject: Re: [TRNSYS-users] Type energy balance
>>>  Vincent,
>>>   When you perform an energy balance on a tank, you need to take into
>>> account its change in temperature between the beginning and the end of the
>>> simulation (output 7 of your Type4). If the tank ends up hotter at the end
>>> of the simulation than it was at the beginning, it has stored some energy.
>>> If it ends up colder, then it has given up some energy. I would imagine
>>> that with 10 nodes, there is some stratification developing in the tank
>>> that is not modeled when you have a fully mixed tank (1 node)
>>> Best,
>>>  David
>>>
>>>
>>> On 10/25/2012 09:40, PARTENAY Vincent wrote:
>>>
>>>  Dear all,****
>>>
>>> ** **
>>>
>>> Typ4a (Storage tank) allows to model a stratified tank with several
>>> temperature nodes. The problem I noticed is that the energy balance of both
>>> sides on the tank can vary depending on the chosen timestep :****
>>>
>>> ** **
>>>
>>> In the attached file, a simplified example, the tank is coupled to an
>>> energy production and energy consumption model (very simple in an
>>> equation). Thermal losses of the tank is set to zero.****
>>>
>>> When I run a simulation with one node (1m height for 0.5m3) for the tank
>>> and a timestep of 0.1hr, I get the same energy on both side (see plotter
>>> “”Power&NRJ”, Esource = 2659kWh and Eload = 2666kWh), slight difference
>>> maybe explained by initial charging period to setpoint temperature.****
>>>
>>> When I run it in the same conditions but with 10 nodes (each 0.1m),
>>> these two energy are different ! While I still have 2666kWh for Eload I
>>> have 3146kWh !****
>>>
>>> When I run it again reducing the timestep from 0.1hr to 0.001 hr, still
>>> with 10 nodes, I get 2666kWh, the energy balance is ok…****
>>>
>>> ** **
>>>
>>> So, my question is : is it necessary to check before every bigger
>>> simulation (that can include lots of tank models) the energy balance of
>>> this model for one defined timestep and boundary conditions to the model or
>>> is there some rules to predefine adapted discretisation for one given
>>> timestep ?****
>>>
>>> ** **
>>>
>>> Kind regards,****
>>>
>>> ** **
>>>
>>> ** **
>>>
>>> *Vincent PARTENAY*
>>>
>>> Energies Renouvelables - Département ESE****
>>>
>>>  ****
>>>
>>> *Centre Scientifique et Technique du Bâtiment*
>>>
>>> 290 Route des Lucioles BP 209 – F 06904 Sophia Antipolis Cedex****
>>>
>>> Tél : +33-(0)4-93-95-67-21****
>>>
>>> Fax : +33-(0)4-93-95-64-31****
>>>
>>> *Évitez d’imprimer vos emails inutilement. Respectez l’environnement****
>>> *
>>>
>>> ** **
>>>
>>> ** **
>>>
>>>
>>> _______________________________________________
>>> TRNSYS-users mailing listTRNSYS-users at cae.wisc.eduhttps://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:+1.608.278.1475d.bradley at tess-inc.com
>>> http://www.tess-inc.comhttp://www.trnsys.com
>>>
>>>
>>>
>>> ---------- 已转发邮件 ----------
>>> From: "Michaël Kummert" <michael.kummert at gmail.com>
>>> To: <trnsys-users at cae.wisc.edu>
>>> Cc:
>>> Date: Thu, 25 Oct 2012 18:19:39 -0400
>>> Subject: Re: [TRNSYS-users] Type energy balance
>>>
>>> If the energy (de)stored between the initial and final state cannot
>>> explain the differences, I think there is another possible cause: Type 4
>>> can have quite large energy balance errors when the nodes are “flushed out”
>>> during one time step. ****
>>>
>>> ** **
>>>
>>> Here is my understanding: ****
>>>
>>> If you have 10 nodes and a total volume of 500 L, that means each node
>>> holds 50 L of water. Using 0.1 h time steps you cannot have a flowrate
>>> through the tank higher than 500 L/h, otherwise you will replace the entire
>>> volume of a node within a time step, and the equations used by Type 4 are
>>> not valid anymore. This would explain that it works again when you reduce
>>> the timestep (with 0.001 h you would need a flowrate of 50000 L/h to
>>> “flush” a node out).****
>>>
>>> ** **
>>>
>>> To my knowledge this problem is specific to Type 4, i.e. it does not
>>> affect the Storage tanks in the TESS libraries (Type 534 etc.) – if you
>>> have access to them that may be a more practical solution than running
>>> 0.001 h timesteps…****
>>>
>>> ** **
>>>
>>> Michaël Kummert****
>>>
>>> Polytechnique Montréal****
>>>
>>> ** **
>>>
>>> *From:* trnsys-users-bounces at cae.wisc.edu [mailto:
>>> trnsys-users-bounces at cae.wisc.edu] *On Behalf Of *David BRADLEY
>>> *Sent:* Thursday, October 25, 2012 17:34
>>> *To:* PARTENAY Vincent
>>> *Cc:* trnsys-users at cae.wisc.edu
>>> *Subject:* Re: [TRNSYS-users] Type energy balance****
>>>
>>> ** **
>>>
>>> Vincent,
>>>   When you perform an energy balance on a tank, you need to take into
>>> account its change in temperature between the beginning and the end of the
>>> simulation (output 7 of your Type4). If the tank ends up hotter at the end
>>> of the simulation than it was at the beginning, it has stored some energy.
>>> If it ends up colder, then it has given up some energy. I would imagine
>>> that with 10 nodes, there is some stratification developing in the tank
>>> that is not modeled when you have a fully mixed tank (1 node)
>>> Best,
>>>  David
>>>
>>> ****
>>>
>>> On 10/25/2012 09:40, PARTENAY Vincent wrote:****
>>>
>>> Dear all,****
>>>
>>>  ****
>>>
>>> Typ4a (Storage tank) allows to model a stratified tank with several
>>> temperature nodes. The problem I noticed is that the energy balance of both
>>> sides on the tank can vary depending on the chosen timestep :****
>>>
>>>  ****
>>>
>>> In the attached file, a simplified example, the tank is coupled to an
>>> energy production and energy consumption model (very simple in an
>>> equation). Thermal losses of the tank is set to zero.****
>>>
>>> When I run a simulation with one node (1m height for 0.5m3) for the tank
>>> and a timestep of 0.1hr, I get the same energy on both side (see plotter
>>> “”Power&NRJ”, Esource = 2659kWh and Eload = 2666kWh), slight difference
>>> maybe explained by initial charging period to setpoint temperature.****
>>>
>>> When I run it in the same conditions but with 10 nodes (each 0.1m),
>>> these two energy are different ! While I still have 2666kWh for Eload I
>>> have 3146kWh !****
>>>
>>> When I run it again reducing the timestep from 0.1hr to 0.001 hr, still
>>> with 10 nodes, I get 2666kWh, the energy balance is ok…****
>>>
>>>  ****
>>>
>>> So, my question is : is it necessary to check before every bigger
>>> simulation (that can include lots of tank models) the energy balance of
>>> this model for one defined timestep and boundary conditions to the model or
>>> is there some rules to predefine adapted discretisation for one given
>>> timestep ?****
>>>
>>>  ****
>>>
>>> Kind regards,****
>>>
>>>  ****
>>>
>>>  ****
>>>
>>> *Vincent PARTENAY*****
>>>
>>> Energies Renouvelables - Département ESE****
>>>
>>>  ****
>>>
>>> *Centre Scientifique et Technique du Bâtiment*****
>>>
>>> 290 Route des Lucioles BP 209 – F 06904 Sophia Antipolis Cedex****
>>>
>>> Tél : +33-(0)4-93-95-67-21****
>>>
>>> Fax : +33-(0)4-93-95-64-31****
>>>
>>> *Évitez d’imprimer vos emails inutilement. Respectez l’environnement****
>>> *
>>>
>>>  ****
>>>
>>>  ****
>>>
>>>
>>>
>>>
>>> ****
>>>
>>> _______________________________________________****
>>>
>>> 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****
>>>
>>> ** **
>>>
>>> http://www.tess-inc.com****
>>>
>>> http://www.trnsys.com****
>>>
>>>
>>> _______________________________________________
>>> TRNSYS-users mailing list
>>> TRNSYS-users at cae.wisc.edu
>>> https://mailman.cae.wisc.edu/listinfo/trnsys-users
>>>
>>>
>>
>> _______________________________________________
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>> https://mailman.cae.wisc.edu/listinfo/trnsys-users
>>
>>
>
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