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Today's Topics:
1. Mistake in Type 19
conduction input wall? (Charron)
2. PID controller (mike matheus)
3. Re: Type51 (Diego A. Arias)
4. Re: PID controller (Diego A. Arias)
5. Re: Mistake in Type 19 conduction input wall? (Diego A. Arias)
6. Re: Mistake in Type 19 conduction input wall? (Charron)
7. Re: MONTHLY SUMMARY STANDARD REPORT (Monika Schulz)
De: Charron, Rémi <remi.charron@nrcan.gc.ca>
À: <trnsys-users@engr.wisc.edu>
Date: Wed, 3 May 2006 13:12:31 -0400
Objet: [TRNSYS-users] Mistake in Type 19 conduction input wall?
Hello,
I believe there is a mistake in the formulation of the conduction input wall for Trnsys Type 19, can someone confirm?
Equation 4.8.3.22 in the manual states that X_i=(Q_i/A_i +s_i)/hc_i for conduction input walls and that the equivalent temperature should be used in calculating Qi or else the effects of absorption of radiation on the inside surface would not be correctly accounted for.
Equivalent temperature includes effects of s_i and the longwave radiation from other surfaces. Wouldn't including s_i in equation 4.8.3.22 be double counting of the absorbed radiation on the surface if T_equivalent is used? If we use zone temperature instead of equivalent temperature, the effect of longwave radiation would not be included.
Rémi
De: "mike matheus" <matheusmike@hotmail.com>
À: trnsys-users@engr.wisc.edu
Date: Wed, 03 May 2006 17:33:03 +0000
Objet: [TRNSYS-users] PID controller
I am creating a project with a PID controller that mixes two air streams to
maintain a set hum. ratio, then heats the air mixture in a crossflow heat
exchanger. The mixing of the air streams is controlled by the PID and works
well as long as the inputs into the heat exchanger are constant. When I add
a pump onto the hot side of the heat exchanger with varying conditions, the
simulation will not run. I get a
series of warnings about (TRNSYS Message
315) connection sequences. Has anybody else had a similar problem with
version 16? Any ideas on how to fix it?
Thank you,
MIke Matheus
_________________________________________________________________
Is your PC infected? Get a FREE online computer virus scan from McAfee®
Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
De: "Diego A. Arias" <daarias@wisc.edu>
Cc: trnsys-users@engr.wisc.edu
À: Amandine LE DENN <amandine.le-denn@tecsol.fr>
Date: Wed, 03 May 2006 13:28:50 -0500
Objet: Re: [TRNSYS-users] Type51
Hi Amandine,
In order to solve the mass balance and energy balance that represent the
process inside the cooling tower, Type51 uses correlations for the
psychrometric properties. Type51 has to perform internal iterations in
order to solve those two equations. It is possible that a combination
of input
conditions are resulting in a very difficult problem to find a
solution for, and the iterations are going out of the limits considered
appropriate for the correlations. Did you connect both the dry bulb
temperature and the wet bulb temperature inputs of the model to the
weather data reader?
My idea to debug this problem is that you use Type51b, and use the
default parameters for the cooling tower. Find the time when the error
is occurring, and look at the inlet conditions. Use this values to
calculate yourself the outlet conditions in the cooling tower: you can
use the mathematical reference (volume 5, section 5.4.17) to do the
calculations. Perhaps you may find an input that is causing the problem.
Please let me know if you have questions debugging this problem.
Best regards,
Diego
Amandine LE DENN wrote:
> Dear users,
>
> About type51b (cooling tower - user supplied coefficient),
what can be
> the different origin of this message:
> "the correlation for the saturation temperature used in the cooling
> tower model was used with an enthalpy value outisde the allowable range".
>
> I am using french meteo data and water temperature level
> is basically [15°C - 28°C]. Mass transfert constant and exponant are
> the default ones, sump volume is 200L.
>
> Trnsys is generating too many of this error, my simulation stop
> automatically after 800 hours.
>
> Thank you for your help,
>
> Amandine LE DENN
> INSA Toulouse
> Mel: amandine.le-denn@tecsol.fr
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> TECSOL
> 105 avenue Alfred KASTLER
> Tecnosud - B.P 434
> 66004 PERPIGNAN cedex
> FRANCE
> Tel: +33(0)4.68.68.16.40
> Fax: +33(0)4.68.68.16.41
>
------------------------------------------------------------------------
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users@engr.wisc.edu
> https://www.cae.wisc.edu/mailman/listinfo/trnsys-users
>
--
Diego A. Arias
TRNSYS Coordinator
Solar Energy Laboratory
University of Wisconsin - Madison
1500 Engineering Drive
Madison, WI 53706
De: "Diego A. Arias" <daarias@wisc.edu>
Cc: trnsys-users@engr.wisc.edu
À: mike matheus <matheusmike@hotmail.com>
Date: Wed, 03 May 2006 17:17:35 -0500
Objet: Re: [TRNSYS-users] PID controller
Dear Mike,
This message is created when the outputs from a component that is
updated at the end of a time-step. Is it possible that you have
connected the output from an integrator as input to another component?
If this is not the case, please feel free to contact your distributor;
they may be able to help you.
Best regards,
Diego
mike matheus wrote:
> I am creating a project with a PID controller that mixes two air
> streams to maintain a set hum. ratio, then heats the air mixture in a
> crossflow heat exchanger. The mixing of the air streams is controlled
> by the PID and works well as long as the inputs into the heat
> exchanger are constant. When I add a pump onto the hot side of the
> heat exchanger with varying conditions, the simulation will not run.
> I get a series of warnings about (TRNSYS Message 315) connection
> sequences. Has anybody else had a similar problem with version 16?
> Any ideas on how to fix it?
>
> Thank you,
>
> MIke Matheus
>
> _________________________________________________________________
> Is your PC infected? Get a FREE online computer virus scan from
> McAfee® Security.
>
http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users@engr.wisc.edu
> https://www.cae.wisc.edu/mailman/listinfo/trnsys-users
>
--
Diego A. Arias
TRNSYS Coordinator
Solar Energy Laboratory
University of Wisconsin - Madison
1500 Engineering Drive
Madison, WI 53706
De: "Diego A. Arias" <daarias@wisc.edu>
Cc: trnsys-users@engr.wisc.edu
À: remi.charron@nrcan.gc.ca
Date: Wed, 03 May 2006 19:58:40 -0500
Objet: Re: [TRNSYS-users] Mistake in Type 19 conduction input wall?
Hi Rémi,
I do not think that there is an error. The formulation of the
conductive heat transfer in Type 19 is the result of an energy balance
on surface i, as follows:
Energy in:
- Q_i :
Conductive heat transfer
- A*s : Radiation absorption on the surface (absorption of solar radiation)
Energy out:
- A*h_c*(T_s,i - T_z) : convective heat transfer to the zone
- A*h_r_ij*(T_s,i - T_s,j) : radiation exchange between surface i and
surface j, using a linearized radiation coefficient. (For simplicity,
let's assume that there are only two surfaces, i and j)
Energy balance yields:
Q_i + A*s = A*h_c*(T_s,i - T_z) + A*h_r_ij*(T_s,i - T_s,j)
You can rearrange these terms as:
(Q_i/A + s)/h_c = (1 + h_r_ij/h_c )*T_s,i - h_r_ij/h_c*T_s,j - T_z
This equation is written in matrix form in equations 5.7.3.19 -
5.7.3.22. I guess that the confusion is given by the second part of the
paragraph, where it explains that Q_i should be evaluated using T_eq. I
have to admit that I am not entire sure of this: if Q_i only has
conductive heat transfer through the wall, you would only need the
actual temperatures on the
surfaces to calculate it.
I will appreciate the comments from the experts on this list.
Best regards,
Diego
Charron wrote:
> Hello,
>
> I believe there is a mistake in the formulation of the conduction input wall for Trnsys Type 19, can someone confirm?
>
> Equation 4.8.3.22 in the manual states that X_i=(Q_i/A_i +s_i)/hc_i for conduction input walls and that the equivalent temperature should be used in calculating Qi or else the effects of absorption of radiation on the inside surface would not be correctly accounted for.
>
> Equivalent temperature includes effects of s_i and the longwave radiation from other surfaces. Wouldn't including s_i in equation 4.8.3.22 be double counting of the absorbed radiation on the surface if T_equivalent is used? If we use zone temperature instead of equivalent temperature, the effect of longwave radiation would not be included.
>
> Rémi
>
>
_______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users@engr.wisc.edu
> https://www.cae.wisc.edu/mailman/listinfo/trnsys-users
>
--
Diego A. Arias
TRNSYS Coordinator
Solar Energy Laboratory
University of Wisconsin - Madison
1500 Engineering Drive
Madison, WI 53706
De: Charron, Rémi <remi.charron@nrcan.gc.ca>
Cc: trnsys-users@engr.wisc.edu
À: "Diego A. Arias " <daarias@wisc.edu>
Date: Thu, 4 May 2006 11:06:27 -0400
Objet: Re: [TRNSYS-users] Mistake in Type 19 conduction input wall?
Thanks Diego,
I was mistaken, and your response helped clarify how the equations for conduction input wall works. I believe the reason you need to use equivalent temperatures comes from the energy balance:
Q_i + A*s = A*h_c*(T_s,i - T_z) + A*h_r_ij*(T_s,i - T_s,j)
You can solve the above equation for Q_i as
follows:
Q_i=A*h_c*(T_S,i-T_eq)
so you would need to pass T_eq to the program that calculates Q_i for the above energy balance to work.
Rémi
-----Original Message-----
From: Diego A. Arias
To: Charron, Rémi
Cc: trnsys-users@engr.wisc.edu
Sent: 03/05/2006 8:58 PM
Subject: Re: [TRNSYS-users] Mistake in Type 19 conduction input wall?
Hi Rémi,
I do not think that there is an error. The formulation of the
conductive heat transfer in Type 19 is the result of an energy balance
on surface i, as follows:
Energy in:
- Q_i : Conductive heat transfer
- A*s : Radiation absorption on the surface (absorption of solar
radiation)
Energy out:
- A*h_c*(T_s,i - T_z) : convective heat transfer to the zone
- A*h_r_ij*(T_s,i - T_s,j) : radiation exchange between surface i and
surface j, using a linearized radiation coefficient. (For simplicity,
let's assume that there are only two surfaces, i and
j)
Energy balance yields:
Q_i + A*s = A*h_c*(T_s,i - T_z) + A*h_r_ij*(T_s,i - T_s,j)
You can rearrange these terms as:
(Q_i/A + s)/h_c = (1 + h_r_ij/h_c )*T_s,i - h_r_ij/h_c*T_s,j - T_z
This equation is written in matrix form in equations 5.7.3.19 -
5.7.3.22. I guess that the confusion is given by the second part of the
paragraph, where it explains that Q_i should be evaluated using T_eq. I
have to admit that I am not entire sure of this: if Q_i only has
conductive heat transfer through the wall, you would only need the
actual temperatures on the surfaces to calculate it.
I will appreciate the comments from the experts on this list.
Best regards,
Diego
Charron wrote:
> Hello,
>
> I believe there is a mistake in the formulation of the conduction
input wall for Trnsys Type 19, can someone confirm?
>
> Equation 4.8.3.22 in the manual states that X_i=(Q_i/A_i
+s_i)/hc_i
for conduction input walls and that the equivalent temperature should be
used in calculating Qi or else the effects of absorption of radiation on
the inside surface would not be correctly accounted for.
>
> Equivalent temperature includes effects of s_i and the longwave
radiation from other surfaces. Wouldn't including s_i in equation
4.8.3.22 be double counting of the absorbed radiation on the surface if
T_equivalent is used? If we use zone temperature instead of equivalent
temperature, the effect of longwave radiation would not be included.
>
> Rémi
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users@engr.wisc.edu
> https://www.cae.wisc.edu/mailman/listinfo/trnsys-users
>
--
Diego A. Arias
TRNSYS Coordinator
Solar Energy Laboratory
University of Wisconsin - Madison
1500 Engineering Drive
Madison,
WI 53706
De: "Monika Schulz" <Schulz@transsolar.com>
Cc: trnsys-users@engr.wisc.edu
À: <jfamailbox-i3er@yahoo.fr>, "Diego A. Arias" <daarias@wisc.edu>
Date: Thu, 4 May 2006 17:01:58 +0200
Objet: Re: [TRNSYS-users] MONTHLY SUMMARY STANDARD REPORT
Dear Jeff,
I attach the respective NTYPE numbers to the output description.
**************************************************************
* *
* MONTHLY SUMMARY STANDARD REPORT *
* *
**************************************************************
SUMMARY VALUES FOR ALL ZONES COMBINED
****************************************************
MONTH HEATING COOLING INFILTR. VENTILAT. SOLAR_RAD. INT_GAINS
- [KWH] [KWH] [KWH] [KWH] [KWH] [KWH]
NTYPE 32 33 35
36 42 (38+34)
ZONE NUMBER IS 1
****************************************************
MONTH HEATING COOLING INFILTR. VENTILAT.
SOLAR_RAD. INT_GAINS
- [KWH] [KWH] [KWH] [KWH] [KWH] [KWH]
NTYPE 30
31 4 5 12 (7+13)
Kind regards
Monika
Hi all,
I'm looking for informations about MONTHLY SUMMARY STANDARD REPORT sorted by Type56a
As exemple INT_GAINS is not gain defined in my BUI ?
Best regards,
JeFF
------------->JeFF
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