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Dear Marion Thanks for your swift reply. I have got
the point and will do that. Your effort is highly appreciated. Regards From:
Marion Hiller [mailto:hiller@transsolar.com] Dear Mehdi, Well, you should use in fact this
equation: IB_N_180_90 = [109,37]*GT([109,36],1)
Because you want to set all radiation data
to 0 if the total radiation [109,36] is less than 1 kJ/hr and not the beam
radiation [109,37]. To be honest, I assume you don’t need this
for the beam radiation at all, because if the total radiation is very very low
you don’t have beam radiation only diffuse. However, it’s consistent and better to
understand if you use the equation. Best, Dipl.-Ing.
Marion Hiller Geschäftsführer:
Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer, Dipl.Phys. Stefan Holst,
Prof. Dipl.-Ing. Bleicher Von: Mehdi
Shahrestani [mailto:mahdishahrestani@yahoo.com] Dear Marion Many thanks for your reply. It is highly
appreciated. Just for double checking could you please
confirm the second line of modification? Your second modification: IB_N_180_90 = [109,37]*GT([109,36],1) Is it correct or it should be:
IB_N_180_90 = [109,37]*GT([109,37],1)
I am waiting for your kind reply Many thanks again Mehdi From:
Marion Hiller [mailto:hiller@transsolar.com] Dear Mehdi, thanks for resending your simplified
files! The error is due to very low radiation
data on the north façade of your model from Type 109 of 0.02 KJ/hr m².
Type 56 does a radiation distribution for
this very low value which yields to a total distribution error of radiation
entering all windows of 3.63 KJ/hr for your 3 floor window. The 2floor model runs fine because there
are less windows leading to an error smaller than 3.6 kJ/hr. As a quick fix I suggest to set radiation
input to Type 56 lower than 1 KJ/hr m² to 0 by the following IT_N_180_90 = [109,36]*GT([109,36],1)
IB_N_180_90 = [109,37]*GT([109,36],1)
In addition, I put it on my list for
Type56 improvements. Best regards, Dipl.-Ing.
Marion Hiller Geschäftsführer:
Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer, Dipl.Phys. Stefan Holst,
Prof. Dipl.-Ing. Bleicher Von: Mehdi
Shahrestani [mailto:mahdishahrestani@yahoo.com] Dear TRNSYS team and users It is around 10 days that
I have got stuck in simulation of a building. After many things that I have
already checked, it seems that there is a bug in Trnsys. Here, I am going to raise
the issue in detail hoping to get some response from users and Trnsys bodies. Project: Modelling of a building
with 3 floors without considering system (just using type 56) Each floor has 20 zones
and the plans of all 3 floors are the same. Followed process: In the first round the
building was drawn in Trnsys3d-SketchUp and imported into the Trnsys. After
importing the *.idf file, a *.tpf file was automatically generated and was working
very well. The problem came up when I needed to reduce simulation time step
from 1 hr to 0.2 hr. (for controller settings in the next steps of my project) Any way, a simple type 56
for a building with 3 floors, each floor 20 zone was not working with 0.2hr
simulation time step. The error is:
“Internal
error in solar radiation distribution (sumsitot) of 56.388 %
at time 56.40wave length band no.3 1:total solar, 2:visual
solar, 3:non visual solar” I was checking every
thing but nothing was wrong. Finally, I sent an Email for users and asked for
help. Christian from TRANSSOLAR and Matt from TESS kindly replied. Matt
suggested me to follow the Christian advice and Christian wrote: “One reason for this can be that in your 3DModel you have infinitesimal
small surfaces. Please check if this is the case and if so you'll have to
redraw the geometry“ Then, I checked every
little part of the 3D model in Sketchup and also imported model in studio but
there was not such evidence. Even though I was quite
sure that there is no such a little surface I redraw the entire model several
times (at least 10 times) precisely but the result was the same and after
importing the *.idf file into studio exactly at 56.4 hr the error comes up
every time. In the next try I decided
to draw and import building floor by floor. After drawing the first floor, it
was imported to the studio. Generated *.tpf file including Type 56 ran with 0.2
hr simulation time step. The result was perfect, and I decided to check the building
with 2 floors. To make the drawing I used the drawing of the first floor
(previously drawn) and copy it on the top of the first floor as second floor
and then import the related *.idf file into studio. Type 56 of the building
with two floors was working in 0.2 hr time step perfectly without error. Then,
I repeat the process and copy the drawing of the second floor and paste it as
third floor in Sketchup. After importing the *.idf of the building with 3
floors, type 56 was only able to run in simulation time step 1.0 hr. when I was
reducing time step to 0.5 or 0.2 the previous error came up. All in all, this approach
proved that there Christian’s expectation was not correct because if it was
correct I could not run the related type 56 for the first floor and second
floor without error as well.( third floor was copy and paste of second floor) Even though it was quite
clear that there is no any small surface (Christian expectation) I was thinking
maybe there is some problem about connection between Sketchup and studio.
Therefore, I decided to insert entire building manually in type 56. The result
of manual filling type 56 was 100% similar to the importing building from
Sketchup. That means, first floor and second floor was running perfectly in
different simulation time step (0.2 hr , 0.5 hr and 1 hr) but just when I added
the third floor, type 56 came into the same error (mentioned above) at the same
time (56.4 hr). By following these two
approaches I have got sure that the error is not because of small and
unattended surface (Christian expectation) and also is not because of importing
*idf file from Sketchup. This error has also
detected by other users Xavier
(2004) which Michaël Kummert was replied and accepted the bug in version 15. My expectation: 1-
There are limits on number of zone
for each type 56. 2-
Weather component (type 109) is
not able to deal with some time steps. 3-
There is a bug in type 56 to run
model with time steps less than 1.0 hr. 4-
There is a bug for solar radiation
distribution within type 56. For further detail
following files are attached: 1-
Folder 1 including related files
of building with two floors developed in Sketchup and imported into
Trnsys which works fine in different time steps (*.idf, *.tpf, *.dck and
*.b17 files) 2-
Folder 2 including related
files of building with three floors developed in Sketchup and imported
into Trnsys which is not working in time steps less than 1.0 hr
(*.idf, *.tpf, *.dck and *.b17 files) Hereby, I was wondering
if anybody could help me. I am not a freelance researcher; I am a PhD student
with dispread need on doing simulation. I hope you consider user situation with
your kind responses. Sorry about the long
story and thanks for your time Regards Mehdi Shahrestani |