[TRNSYS-users] Double bypass - Mass balance discrepancies (no errors in lst file...)

[Flynn Ciaran]

Dear TRNSYS-users,

As part of my project, I have modeled a double bypass from a storage tank to a heat pump, but I am getting mass balance discrepancies (even though there are no such errors mentioned in the lst file). I have attached a diagram of the layout to this email (similar to Figure 4.6.2-4).

I only seem to be getting this problem when both massflow4 and massflow5 are non-zero. In the screenshot attached, a slight difference in mass flow rates can be observed between massflow2(AtoC) and massflow2(DtoB). Also, massflow4 at the diverter outlet is slightly different to the borehole flow rate...

Has someone encountered this before? I have looked over the diverter equations and I tried to reduce the time step down to 0.01 hour but that doesn't solve the problem. I have a simple example of this available, so I can send that on if someone would like to take a look.

Thanking you in advance,
Ciarán

----------------------------------------
Ciarán Flynn
Project Researcher
Aalto University - Department of Energy Technology
P.O.Box 14100, 00076 Aalto
Otakaari 4, 02150 ESPOO

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