[TRNSYS-users] problem with type 109 user format

[Eleni Ampatzi]

Dear Knut,

Thank you very much. Your answer is very helpful. It did not make sense to me why the software would identify only a limited number of wrong radiation values. By the way, how can  I increase the maximum number of warnings allowed in a simulation?

In my case, the simulation is not aborted, it is completed, but obviously only the first 720 values with wrong radiation are corrected by the software (I guess 720 are the max allowed warnings?). As my data is in 5 min intervals, I would expect that the values which should be set to zero are much more(around 10-30.000). In my List file I get the message:
---------------------------------------------------------------
Radiation while sun is down found  720 times
only the first 10 warnings with data info are printed 
check: - Time of first data line
       - Longitude and Latitude
REMARK: these radiation values are set to ZERO !
---------------------------------------------------------------
And then messages like this:
---------------------------------------------------------------
***** WARNING FROM UNIT   4 TYPE 109 DATA READER
RADIATION DATA READ IN FROM FILE ==>C:\STACS\Weather_data\year 2007 analysis\Metsite_year2007_weatherdata.109
AT LINE #   13 ARE SET TO ZERO SINCE SUN IS DOWN, ORIGINAL VALUE:   14.05 W/m²
---------------------------------------------------------------
I will correct the file. Thank you again,

Best Regards

Eleni Ampatzi
WSA, Cardiff University


>>> <knut.erik.enerstvedt at niva.no> 04/03/08 9:19 AM >>>
Eleni,

After looking at your attached .109 file, it seems to me that the radiation
values are positive even at nighttime. This must be due to a small amount
of radiation from the ground and into space. TRNSYS expects radiation to be
zero when the sun is down, so if this is not the case TRNSYS will set the
values to zero and print a warning message to the List file each time this
happens. After a while, the maximum number of allowed warnings is reached,
an error message is printed and the simulation is aborted. I have
experienced a similar problem, but then the radiation values in my weather
data were negative when the sun was down. TRNSYS could not handle this
either, so my solution to the problem was to set all negative radiation
values to zero. This had no effect on my simulation results, as I was only
interested in radiation coming from the sun and to the ground. I guess that
this solution might not be as easy for you as it was for me, since all your
radiation values are positive. Maybe you can program an algorithm that runs
through your .109 file, compares radiation values with time of day and sets
them zo zero if necessary. A quick solution to the problem is of course to
increase the maximum number of warnings allowed in a simulation, although
this also seems like a temporary solution.

I hope this answer was helpful in some way.

Kind regards,
Knut Erik Enerstvedt



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