Dear all,
I make a simulation. The cooling set temperature is 24*Summer schedule
(2162 h to 6552 h), The heating set temperature is 21*Winter schedule (the
rest hours). After running, however, it appears WEIRD phenomenon. Please
see the ATTACHED Energy_zone.BAL file. During the winter period, there are
Qcools and Qcool is very large up to 47000 kJ. And then it results in wrong
BAL_ENERG, it is not 0.
Please give me some advices and solutions to that!
Many thanks in advance!
Br.
wang
2012/6/11
Dear Wang,
As far as I understand, the cooling set temperature you define in your
model is :
* 24?C in summer, which seems to be correct
* and 0?C in winter... which seems to be wrong, since you don't
refresh your thermal zone at 0?C in winter!
That's why you obtain huge cooling loads.
BAL_ENERGY is not 0 because you heat and cool in the same time in winter.
I think you'd better put for cooling temperatures
* 35?C in winter (no cool) - heating temperature at 21?C
* 24?C in summer
which may be translated in an equation tool by something like :
* summer = GE(TIME,2162)*LT(TIME,6552)
* winter = 1 - summer
* Tcool = 35*Winter - 9*Summer
Best regards
------------------------------------------------------------------------
www.itf.biz
www.itf.biz
Adrien JEZEQUEL
Simulations Thermiques Dynamiques
*ITF*
62, Rue du Bolliet
73230 St Alban Leysse
FRANCE
Phone :
Fax :
Mail:
+33(0) 479 750 029
+33(0) 479 852 122
a.jezequel at itf.biz ou aj at itf.biz
/Afin de contribuer au respect de l'environnement, merci de n'imprimer
cet e-mail que si n?cessaire
Please, consider our environmental responsability before printing this email
/
Le 12/06/2012 14:55, ?? a ?crit :
Dear Adrien Jezequel,
Thanks for your quick reply!
Tcool = 35 - 9 * Summer means if in summer, Tcool = 26 ?C?
I tried to run the simulation based on your solution Tcool = 35 - 9 * Summer,
the result is also like the last Attached.
Oppositely, it is not my heating system seems to work all the time, it is
my cooling system seems to work all the time.
I set internal gains all the year.
Please see the Attached *.tpf and *.bui files, if you have free time ,
please help me have a look and give me some solutions.
Many thanks in advance!
Br.
wang
2012/6/12 ITF - Adrien JEZEQUEL
Dear Wang,
You are right : the Tcool I gave you was equal to 26, not to 24?C. Tset
value is not important as well, the most important is that you
understand how to do to define Tset.
In your model, your heating and cooling advices seem to work fine. Your
problem comes frome your internal gain : 31 people are defined all the
time in a room of approximatively 80 m?, without schedule.
Because of your important internal gains, air temperature increases
until 35?C in winter. Then air temperature is refreshed because Tcool =
35?C in winter.
In summer, air is cooled at 24?C, because this is the temperature you
define in your cooling advice.
Best regards
------------------------------------------------------------------------
www.itf.biz
www.itf.biz
Adrien JEZEQUEL
Simulations Thermiques Dynamiques
*ITF*
62, Rue du Bolliet
73230 St Alban Leysse
FRANCE
Phone :
Fax :
Mail:
+33(0) 479 750 029
+33(0) 479 852 122
a.jezequel at itf.biz ou aj at itf.biz
/Afin de contribuer au respect de l'environnement, merci de n'imprimer
cet e-mail que si n?cessaire
Please, consider our environmental responsability before printing this email
/
Le 12/06/2012 18:19, ?? a ?crit :
Dear Wrang,
You are right : the Tcool I gave you was equal to 26, not to 24?C. Tset
value is not important as well, the most important is that you
understand how to do to define Tset.
In your model, your heating and cooling advices seem to work fine. Your
problem comes frome your internal gain : 31 people are defined all the
time in a room of approximatively 80 m?, without schedule.
Because of your important internal gains, air temperature increases
until 35?C in winter. Then air temperature is refreshed because Tcool =
35?C in winter.
In summer, air is cooled at 24?C, because this is the temperature you
define in your cooling advice.
Best regards
------------------------------------------------------------------------
www.itf.biz
www.itf.biz
Adrien JEZEQUEL
Simulations Thermiques Dynamiques
*ITF*
62, Rue du Bolliet
73230 St Alban Leysse
FRANCE
Phone :
Fax :
Mail:
+33(0) 479 750 029
+33(0) 479 852 122
a.jezequel at itf.biz ou aj at itf.biz
/Afin de contribuer au respect de l'environnement, merci de n'imprimer
cet e-mail que si n?cessaire
Please, consider our environmental responsability before printing this email
/
Le 12/06/2012 18:19, ?? a ?crit :
Dear Adrien JEZEQUEL,
Many thanks for your patient reply and checking for my programs.
You are right. The problem is indeed Internal Gains. I define a Schedule
based on your advice. After running, it seems better than the previous.
However, there are some unreasonable situations. Please see the Attached
image.
1. Tair and Top are higher than the set point 21 ?C in winter all the time.
Tair is closed to 23 ?C basically, and it is only 21 ?C when no occupancy.
I guess the reason is the compensation of internal gains and mechanical
ventilation.
Do you have some solutions to make sure that the set point is 21 ?C in
winter?
2.Tair and Top are lower than the set point 26 ?C in summer all the time.
The maximal is only 25.4 ?C. I guess the reason is due to the influence of
mechanical ventilation, and only a few hot days (Toutdoor>26 ?C) in summer.
I would like to ensure that the set point is 26 ?C in summer. Do you have
some solutions to that problem? Only reduce air change rate of mechanical
ventilation? Anything else?
3.Qinf and Qvent are different all over the year although the infiltration
rate and ventilation rate settings are the same all over the year. I think
Since the weather conditions especially outdoor temperature, wind direction
and wind velocity are different all over the year. Am I right?
4. Based on Energy_zone.BAL file, Qcool is 0 all the time. Do you have some
ideas? I think it is due to mechanical ventilation and only a few hot days
(Toutdoor>26 ?C) in summer. Anything else reasons?
Many thanks in advance!
Br.
wang
2012/6/13 ITF - Adrien JEZEQUEL
Dear Mr. Adrien,
Many thanks for your patient and careful answers!
You are right!
Set point for cooling is 26?C in your model. The problem comes from your
ventilation system : Temperature of air flow = 17?C in summer. So your
ventilation system cools your thermal zone.. Your cooling system is then
shunted since Tair < 26?C, that's why you obtain QCool = 0. i advice you to
adjust your air flow temperature.
Due to the lower set temperature of ventilation in summer, the Qcool = 0.
Since 17 ?C is our design standard, so generally it can't be adjusted. In
addition, I found there is another Weird phenomenon about Qcool and Tcool.
I adjust Tcool based on your suggestion and Equation (Tcool = 35 - 9 *
Summer ). I change it into e.g. Tcool = 35 - 8/10/11.../25 * Summer etc.,
but Tcool doesn't work i.e. Tair_room is keeping the same temperature
(please see the 1st attached on line plotter) in all the set point Tcool
situatuins (27/25/24.../10 ?C), therefore, Qcool is 0 all the time. I
checked and adjusted many times for this simulation. It also exists this
problem. It made me drive the nuts.
If you are free, please help me have a look the program and give me some
solutions or advices. Pleasae see the 2nd and 3rd attached.
Many thanks in advance! I'm very appreciated for all your help!
Br.
wang
2012/6/13 ITF - Adrien JEZEQUEL
Dear Mr. Adrien,
Many thanks for your quick reply!
Did you put a lower ACH for the simulation already? After that, the cooling
system works fine? I did. I set the ACH from 2.0 to 0.5 1/h, however, Qcool
is still 0, in addition, Tair_room in summer is up to 33/34 ?C. It means
the cooling system is still not working after reducing the ACH of
ventilation system.
So I think it is not reason of ventilation system. I guess there is
something wrong with the cooling system in TRNSYS. But I still can't find
the solution.
Please give us some suggestions for that! I don't know why there are so
many bugs or problems in TRNSYS although it has been a mature BES tool.
Many thanks in advance!
Br.
wang
2012/6/18 Adrien JEZEQUEL - ITF