[TRNSYS-users] Energy losses on solar collector's heat exchanger before the loop starts

[Javier Vega via TRNSYS-users]

Hi again!

Jeff, after your response, I've tried several things. The interesting
results I've got is that in the same configuration I have, supressing Type
93 (I put that to soften the control function before noticing this problem)
and connecting the "Fraction of Maximum Flow" directly to the pump's
"Control function" input, I get good results. As soon as I put the proper
capacitance of the collector's array, the negative peaks start to pop up
again.

Trying with the "Control Colector technique" it's the same. I've set the
control collector without mass and connecting the control output to Type
695 pump. Then, if I set the real collector without mass, i get good
results, if I put mass on the real collector, I get the negative peaks.

Is it really a control/numerical problem, or is it that because the
capacitance of the collectors, everytime the pump starts, the collectors
must heat first with the energy from the solar tank?

Again, I attach some pictures and plots.

Thanks in advance,
Javier Vega Benavente
Mechanical Engineering Student, Universidad de Concepción, Chile
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