Reordering `PlantLoop` objects give different results

[lymereJ]

Reordering `PlantLoop` objects give different results

[lymereJ]

The models have an EMS program, commenting out the program reduces the differences but they're still there.

[mjwitte]

Try increasing " Minimum Plant Iterations" in ConvergenceLimits to see if that reduces the differences (without EMS).

[lymereJ]

Increasing the Minimum Plant Iterations (without EMS) seems to increase the energy use differences:

Minimum Plant Iterations = 2:

• Case 1:
  

• Case 2:
  

• Case 3:
  

Minimum Plant Iterations = 5:

• Case 1:
  

• Case 2:
  

• Case 3:
  

Case 1 and Case 3 see to always have similar results.

PlantLoop objects order: (CWH is chilled water loop, CW is condenser water loop)

• Case 1: CW, CWH secondary, CWH primary
• Case 2: CWH primary, CWH secondary, CW
• Case 3: CWH secondary, CW, CWH primary

[rraustad]

@EnergyArchmage any insight? I do know that HeatExchanger:FluidToFluid may have some issues with how node conditions are passed through in the plant.

[EnergyArchmage]

I think the cool tools cooling tower model is suspect, be interesting to try with the Merkel version.

I would try a test to reorder the Sizing:Plant objects to match the order of the PlantLoop objects. I keep finding places where the plant sizing index and plant loop index are mixed up. But if the eio's are the same then that probably isn't it.