Re: [TRNSYS-users] problem with type 109 user format

[knut.erik.enerstvedt@niva.no]

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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