Please check the appended screenshot to see how my TRNSYS project looks like (note that this screenshot is zoomed in the loop I am having problems with).
In my project, a variable speed pump flow rate is set with a control function. A tempering valve controls the pump entering temperature according to a set temperature (read from an external file). It is a very common system.
However, the problem is the following : mass balance check fails across the pump (warning messages + I have checked the results and indeed, it occurs during most of the timesteps). The difference between input and output flow rates can be as large as 100%. On the other hand, mass balance is checked when control signal is 0 or 1 (rated flow rate). Connections are set as it follows :
- Tee piece outlet temperature / flowrate --> pump inlet temperature / flowrate
- Pump outlet flowrate --> valve inlet flowrate
- Valve inlet temperature from external file
- Valve set temperature from external file
- Pump control signal from external file
Please feel free to ask for more information about the project.
Thanks in advance for your help,
Have a good day,
Regards,
--
Damien CASETTA
INSA Lyon / Génie Energétique et Environnement
ENERTECH / Cabinet SIDLER
26160 Félines sur Rimandoule
Tél & Fax : 04 75 90 18 54
