[TRNSYS-users] Negative value of Radiation in TRNSYS 16
David BRADLEY
d.bradley at tess-inc.com
Mon Oct 29 10:06:59 PDT 2012
Wang,
As it says in all of the"More" button comments for the Type9
"Interpolate or not" parameter and also in the mathematical description
of Type9, you should NOT use Type9 to interpolate solar radiation data.
Type9 interpolates linearly, which is a poor assumption for the way in
which solar radiation behaves over an hour. Furthermore, the point of
Type16 (solar radiation processor) is to carry out an interpolation of
solar radiation for timesteps smaller than an hour.
I would highly recommend that you run a simulation with ONLY Type9 and
Type65. Plot out all of the values that you are reading from your file
and make sure that they are all being treated correctly. It can be
somewhat tricky to set the "average or instantaneous value" parameter
and the "interpolate or not" parameters. Only after you have verified
the data is being read in properly should you then adda Type16 to the
project to make sure that solar radiation is being processed correctly;
again, there are some parameters that can be challenging to set correctly.
Regards,
David
On 10/29/2012 05:17, 王洋 wrote:
> 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
> <mailto: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
> <mailto:trnsys-users-request at cae.wisc.edu>>
>
> Send TRNSYS-users mailing list submissions to
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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
> <mailto:wanghongyang1767 at gmail.com>>
> To: trnsys-users at cae.wisc.edu <mailto: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
> <mailto:trnsys-users-request at cae.wisc.edu>>
>
> Send TRNSYS-users mailing list submissions to
> trnsys-users at cae.wisc.edu <mailto: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
> <mailto:trnsys-users-request at cae.wisc.edu>
>
> You can reach the person managing the list at
> trnsys-users-owner at cae.wisc.edu
> <mailto:trnsys-users-owner at cae.wisc.edu>
>
> 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
> <mailto:d.bradley at tess-inc.com>>
> To: PARTENAY Vincent <vincent.partenay at cstb.fr
> <mailto:vincent.partenay at cstb.fr>>
> Cc: "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: 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 <tel:%2B33-%280%294-93-95-67-21>
>>
>> Fax : +33-(0)4-93-95-64-31 <tel:%2B33-%280%294-93-95-64-31>
>>
>> *Évitez d’imprimer vos emails inutilement. Respectez
>> l’environnement*
>>
>>
>>
>> _______________________________________________
>> TRNSYS-users mailing list
>> TRNSYS-users at cae.wisc.edu <mailto: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 <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.trnsys.com
>
>
>
> ---------- 已转发邮件 ----------
> From: "Michaël Kummert" <michael.kummert at gmail.com
> <mailto:michael.kummert at gmail.com>>
> To: <trnsys-users at cae.wisc.edu
> <mailto: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>
> [mailto: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
> <mailto: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
> <tel:%2B33-%280%294-93-95-67-21>
>
> Fax : +33-(0)4-93-95-64-31
> <tel:%2B33-%280%294-93-95-64-31>
>
> *Évitez d’imprimer vos emails inutilement. Respectez
> l’environnement*
>
>
>
>
> _______________________________________________
>
> TRNSYS-users mailing list
>
> TRNSYS-users at cae.wisc.edu <mailto: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 <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.trnsys.com
>
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu <mailto:TRNSYS-users at cae.wisc.edu>
> https://mailman.cae.wisc.edu/listinfo/trnsys-users
>
>
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu <mailto:TRNSYS-users at cae.wisc.edu>
> https://mailman.cae.wisc.edu/listinfo/trnsys-users
>
>
>
>
>
> _______________________________________________
> 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
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