Jérôme,
There isn't much that you can do about the second error (radiation
exceeding extraterrestrial). It happens quite often and has to do
with the sub-hourly interpolation used. If it happens a lot during
your simulation (5 percent of the timesteps?) then it might be worth
having your distributor look at it.
For the issue about having the printer rounding. Trnsys takes the
timestep that you indicate (in decimal hours) and tries to fit it to
a ratio of two integers. If you enter a 10 minute timestep as
0.16666666666666666666667 (in other words lots of decimal places)
then chances are good that Trnsys will find 10/60 for the best
representation. If you put in 0.1667, however, it can find a crazy
representation of the time step and what ends up happening is that
the printer is trying to print at the end of the hour and there is
no time step at the end of the hour (0.1667 does not divide evenly
into 1). The safest approach is as follows:
in your control cards, set the simulation time step to a "string"
and enter "DELT" in the field.
in the small window at the bottom of the control cards, enter the
following:
EQUATIONS 1
DELT = 10/60
in this way you are giving TRNSYS the exact ratio of integers that
you want it to use and your printer and timestep will line up with
each other.
Best,
David
On 11/19/2010 08:32, wrote:
Hi everybody,
i have 2 warning messages in TRNSYS16 that i dont
succeed in fixing them.
The first one refers to output printers Type25a :
the printer has rounded the reset time to an even
number of steps.-Please check to make sure that it
doesnt adversly affect your simulation results.
I think it is because i have put my steptime (in
control cards) to 10min that is to say 0.1667h. I
havent this message when i put back 1h as a timestep.
I think the cause in printer is the 1st parameter set
to STEP with unit=hr. Could you tell me what STEP
represents? I was thinking this value to be the
steptime in control cards.
The second message refers to irradiation :
"the direct beam is greater than the maximum allowed
for this timestep. The extraterrestrial radiation has
been used for this time step."
this message refers to unit 60 which is type16c
(radiation processors).
i read my total horizontal radiation from datareader
(type 9c). the maximum value in my file for radiation
is 975W/m² (3510kJ/hr.m²). I use a multiplication
factor in data reader for radiation (3.6) in order to
switch to kJ/hr.m² and i send the output to radiation
processor which solar constant parameter is seto to
4920kJ/hr.m².
Maybe the problem is about units of the input from
data reader. I have tried to send the output of
datareader to unit conversion routine (type57). I put
parameter 1=17 parameter 2 and 3=1.
Thank you for reading. I hope i have put enough
details in order you can understand and help me.
_______________________________________________
TRNSYS-users mailing list
TRNSYS-users@cae.wisc.edu
https://www-old.cae.wisc.edu/mailman/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@tess-inc.com
http://www.tess-inc.com
http://www.trnsys.com
|