Hi,
I'm a Chilean mechanical engineering student currently working in my thesis. I'm doing simulation of combined Solar and Heat Pump Systems and recently I'm stuck with this problem, with no clue of how to solve this situation.
I wanted to describe a 5 stage building with 78 appartments. As a result, I made 89 thermal zones on the Type 56 module. I worked before on little 1 to 5 thermal zone buildings. The thing is, I have a 1 hour interval meteorological data file and the system runs well if I simulate with 1 hour timestep. But, if I try to do simulations with shorter timesteps (which is a necessity for what I'm doing) I get the following warnings and fatal error:
Examples:
*** Warning at time : 355.333333
Generated by Unit : 4
Generated by Type : 16
Message : The calculated horizontal diffuse radiation exceeded the horizontal extraterrestrial radiation and was set to the extraterrestrial for 2 timesteps during the simulation.
*** Fatal Error at time : 355.333333
Generated by Unit : 2
Generated by Type : 56
Message : Internal error in solar radiation distribution (sumsitot) of 76.095 % at time 355.33wave length band no.3 1:total solar, 2:visual solar, 3:non visual solar
I've lowered the timestep simulation with the control cards in the simulation studio to 45min-30min-15-min-5min, and I've also done my own weather file with a 5min timestep. The problem appears with all previous scenarios, but the fatal error always comes in a different timestep if I change the interval.
It's important to say I've noticed the solar radiation data must be interpolated by Type 16, and that's what I'm doing (if I haven't done anything wrong with that).
My biggest problem with this issue is that I don't understand it, so I don't know how to track it. If the problem comes from solar radiation, why would type 16 make a bad interpolation? And especially, why is it Type 56 the one who gives the fatal error?. I've tried to look for "sumsitot" in the trnsys documentation and the internet but I haven't found anything that helped me understand it.
Hoping for help,sincerely thanks
Javier Vega Benavente
Mechanical Engineering Student, Universidad de Concepción, Chile
Contact: (+569) 93529373