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!
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Le 13/06/2012 12:58, 王洋 a écrit :
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.
In winter your Tair is equal at least at Tset
heat (21°C in your model). Temperatures grow up due to solar and
internal heat gains, that's why you obtain Tair > 21°C in
winter.
Do you have some solutions to make sure that the set point is 21
°C in winter?
check Tair without internal heat gain and
solar gain to be sure that your thermal zone is heated at 21°C.
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?
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.
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?
Yes, you are right. But it's very difficult to
take into account accuracy airflows due to infiltration rate,
since this is generaly due in one hand to imperfections and in
other hand, as you say, to local situation : you have to estimate
wind velocity and direction near your building, then, calculate
pressure coefficient on each elements of your facade, and then
approach your infiltration rate with a law like m' = C.dp.n.
You may find some litteratures from Martin Liddament but in first
approximation, I advice you to take a constant value equal to
1/20eme airflowrate obtain under 50Pa which seems to be perfect
for energy studies.
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?
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 m², 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.
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contribuer au respect de l'environnement, merci de
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Le 12/06/2012 18:19, 王洋 a écrit :
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.
Regarding
your heating system it may be something like
:
Theat =
21*Winter
Regarding
your attached picture, your heating system
seems to work all the time.
In summer, either you cool at 21°C, either
there is no internal gains defined, and you
heat at 21°C.
Check your differents inputs.
You can procede step by step (internal gain
= 0, ventilation = 0, infiltration rate =
0...) to see the influence of each
parameters in your model to catch your
issue.
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de l'environnement, merci de n'imprimer
cet e-mail que si nécessaire
Please, consider our
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Le 12/06/2012 17:47, 王洋 a écrit :
Dear
Adrien Jezequel,
Many
thanks!
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
For Tcool =
35*Winter - 9*Summer, do you
mean if in winter, Tcool = 35 °C, so
Cooling doesn't work ; if in summer,
Tcool = -9°C or 24 °C?
Meanwhile, another weird phenomena
appear: After running based on your
solution in winter, indoor temperature
becomes 35 °C also not 21 °C, although I
set heating temperature as 21 °C; in
summer, however, indoor temperature
becomes 21 °C. Please see the Attached
On-Line Plotter image.
Furthermore, when I create another Tcool
equation as 35*winter+24*summer,
the result is also like the Attached
On-Line Plotter image.
Please give me some solutions or
advices!
I think the point how to set that
Cooling doesn't work in winter? The
possible reason of that problem is that
I also set a Mechanical Ventilation in
winter (Tset=19 °C) and summer (Tset=17 °C). I guess Maybe the Mechanical Ventilation will
influence on Cooling and heating?
---------- 已转发邮件 ----------
From: <jose.gonzalez@imdea.org>
To: trnsys-users@cae.wisc.edu
Cc:
Date: Tue, 12 Jun 2012 14:56:21 +0200
(CEST)
Subject: Re: [TRNSYS-users]
TRNSYS-users Digest, Vol 90, Issue 23
I am out of the office from Monday,
June 11 to Friday, June 15 and unable
to respond at this time.
Afin
de contribuer au respect de
l'environnement, merci de
n'imprimer cet e-mail que si
nécessaire
Please,
consider our environmental
responsability before
printing this email
Le 12/06/2012 14:55, 王洋 a écrit :
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!
---------- 已转发邮件 ----------
From: <jose.gonzalez@imdea.org>
To: trnsys-users@cae.wisc.edu
Cc:
Date: Mon, 11 Jun 2012
16:07:28 +0200 (CEST)
Subject: Re: [TRNSYS-users]
TRNSYS-users Digest, Vol 90,
Issue 21
I am out of the office from
Monday, June 11 to Friday,
June 15 and unable to respond
at this time.
I will be out of the office
from June 8 - 23 on a
backpacking trip with my son
and his Venture Crew at
Philmont Scout Ranch in New
Mexico. I will not have access
to email or phone service
while I am gone, but I will
reply to your message as soon
as possible after I return to
the office on Monday, June
25th.
In order to simulate a
water-cooled chiller, first
I need to create the 2
external files for this
component.
I'm trying to find some
catalogues with information
of a 40 to 45 kW
water-cooled chiller but the
web pages I run into it, ask
me to register, but I'm
still waiting the username
and pasword. Does anyone has
a catalgoue with this type
of info regarding this
cooling capacity machine?
Best regards,
Andrés
--
Andrés Montero I.
---------- 已转发邮件 ----------
From: Santeri Siren <santeri.siren1@gmail.com>
To: "trnsys käyttäjät" <trnsys-users@cae.wisc.edu>
Cc:
Date: Mon, 11 Jun 2012
19:56:40 +0300
Subject: [TRNSYS-users] Type
673 heating problem
Dear all,
I cant make type673 heating
mode to work. Cooling mode
works just fine but when I
change the cooling control
signal to 0 and heating
control signal to 1 it doesnt
work anymore. When the heating
mode is used nothing happens.
Does anyone know why?
---------- 已转发邮件 ----------
From: Mazen Darwish <mazentd@gmail.com>
To: trnsys-users@cae.wisc.edu
Cc:
Date: Tue, 12 Jun 2012 16:05:51 +0200
Subject: [TRNSYS-users] Flue gas stack
in TRNSYS
Hello everyone ,
Is there a way to model a flue
gas stack in TRNSYS , i need to
recirculate hot air and flue gases
from the economizer in an HRSG back
to a solar tower .
I will be out of the office from June
8 - 23 on a backpacking trip with my
son and his Venture Crew at Philmont
Scout Ranch in New Mexico. I will not
have access to email or phone service
while I am gone, but I will reply to
your message as soon as possible after
I return to the office on Monday, June
25th.
