Variable Speed Pump and Two-way Common Pipe Causes Hard Crash

[mitchute]

Issue overview

A user submitted an IDF where a variable speed pump and two-way common pipe were used. This configuration is currently unsupported in EnergyPlus. Instead of throwing a warning and falling back to a constant speed pump, the file hard crashed with a segmentation fault.

Backtrace

#0  0x00007ffff30be08f in ObjexxFCL::IndexRange::contains (this=0x1e8, i=1) at /home/mitchute/Projects/EnergyPlus/third_party/ObjexxFCL/src/ObjexxFCL/IndexRange.hh:346
#1  0x00007ffff3655f2a in ObjexxFCL::Array1<EnergyPlus::DataPlant::BranchData>::contains (this=0x1a8, i=1) at /home/mitchute/Projects/EnergyPlus/third_party/ObjexxFCL/src/ObjexxFCL/Array1.hh:941
#2  0x00007ffff3654012 in ObjexxFCL::Array1<EnergyPlus::DataPlant::BranchData>::operator() (this=0x1a8, i=1) at /home/mitchute/Projects/EnergyPlus/third_party/ObjexxFCL/src/ObjexxFCL/Array1.hh:861
#3  0x00007ffff37ae14d in EnergyPlus::PlantUtilities::SetActuatedBranchFlowRate (state=..., CompFlow=@0x7fffffffa488: 0, ActuatedNode=77, plantLoc=..., ResetMode=false) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/PlantUtilities.cc:343
#4  0x00007ffff45ddf9d in EnergyPlus::HVACInterfaceManager::ManageTwoWayCommonPipe (state=..., plantLoc=..., TankOutletTemp=35) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HVACInterfaceManager.cc:1183
#5  0x00007ffff45dcb3e in EnergyPlus::HVACInterfaceManager::UpdateCommonPipe (state=..., TankInletPlantLoc=..., CommonPipeType=EnergyPlus::DataPlant::CommonPipeType::TwoWay, MixedOutletTemp=@0x7fffffffa9e8: 0) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HVACInterfaceManager.cc:844
#6  0x00007ffff45daa94 in EnergyPlus::HVACInterfaceManager::UpdatePlantLoopInterface (state=..., plantLoc=..., ThisLoopSideOutletNode=70, OtherLoopSideInletNode=77, OutOfToleranceFlag=@0x5555587221c8: true, CommonPipeType=EnergyPlus::DataPlant::CommonPipeType::TwoWay)
    at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HVACInterfaceManager.cc:521
#7  0x00007ffff4c00c71 in EnergyPlus::DataPlant::HalfLoopData::solve (this=0x555558721a90, state=..., FirstHVACIteration=true, ReSimOtherSideNeeded=@0x5555587221c8: true) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/Plant/LoopSide.cc:146
#8  0x00007ffff362d8f8 in EnergyPlus::PlantManager::ManagePlantLoops (state=..., FirstHVACIteration=true, SimAirLoops=@0x555555647628: true, SimZoneEquipment=@0x55555564762b: true, SimNonZoneEquipment=@0x55555564762c: true, SimPlantLoops=@0x55555564762a: true, 
    SimElecCircuits=@0x555555647629: true) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/Plant/PlantManager.cc:216
#9  0x00007ffff45ed3b5 in EnergyPlus::HVACManager::SimSelectedEquipment (state=..., SimAirLoops=@0x555555647628: true, SimZoneEquipment=@0x55555564762b: true, SimNonZoneEquipment=@0x55555564762c: true, SimPlantLoops=@0x55555564762a: true, SimElecCircuits=@0x555555647629: true, 
    FirstHVACIteration=@0x7fffffffadc5: true, LockPlantFlows=false) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HVACManager.cc:1867
#10 0x00007ffff45e5bcf in EnergyPlus::HVACManager::SimHVAC (state=...) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HVACManager.cc:862
#11 0x00007ffff45e149a in EnergyPlus::HVACManager::ManageHVAC (state=...) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HVACManager.cc:279
#12 0x00007ffff471a60e in EnergyPlus::HeatBalanceAirManager::CalcHeatBalanceAir (state=...) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HeatBalanceAirManager.cc:4575
#13 0x00007ffff46f1f3b in EnergyPlus::HeatBalanceAirManager::ManageAirHeatBalance (state=...) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HeatBalanceAirManager.cc:159
#14 0x00007ffff47c8157 in EnergyPlus::HeatBalanceSurfaceManager::ManageSurfaceHeatBalance (state=...) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HeatBalanceSurfaceManager.cc:183
#15 0x00007ffff475663a in EnergyPlus::HeatBalanceManager::ManageHeatBalance (state=...) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/HeatBalanceManager.cc:209
#16 0x00007ffff39e5cbb in EnergyPlus::SimulationManager::SetupSimulation (state=..., ErrorsFound=@0x7fffffffbd53: false) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/SimulationManager.cc:2092
#17 0x00007ffff39d6c31 in EnergyPlus::SimulationManager::ManageSimulation (state=...) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/SimulationManager.cc:352
#18 0x00007ffff30ca1d7 in RunEnergyPlus (state=..., filepath="") at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/api/EnergyPlusPgm.cc:421
#19 0x00007ffff30c92c7 in EnergyPlusPgm (args=std::__debug::vector of length 4, capacity 4 = {...}, filepath="") at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/api/EnergyPlusPgm.cc:240
#20 0x0000555555580be7 in main (argc=4, argv=0x7fffffffd7a8) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/main.cc:61

A temporary workaround is to use a constant speed pump.

in.idf.txt

Operating System (Multiple choices)

Ubuntu

Operating System Version

24.04

Version of EnergyPlus

26.1

Unmethours link or helpdesk ticket number

N/A

Defect file

No response

[rraustad]

From your backtrace, this is the line where my debugger stops.

#3 0x00007ffff37ae14d in EnergyPlus::PlantUtilities::SetActuatedBranchFlowRate (state=..., CompFlow=@0x7fffffffa488: 0, ActuatedNode=77, plantLoc=..., ResetMode=false) at /home/mitchute/Projects/EnergyPlus/src/EnergyPlus/PlantUtilities.cc:343

In my case it looks like I am running out of my 8 GB of memory:

[rraustad]

No, it's not lack of memory. The problem is that this plantLoc local was written long ago before plantLoc took on other information.

    PlantLocation TankOutletPlantLoc = {LoopNum, TankOutletLoopSide, 0, 0};
    ManageTwoWayCommonPipe(state, TankOutletPlantLoc, TankAverageTemp);

When I correct this local (the new references in plantLoc for loop, side, and branch), and correct the same issue in ManageTwoWayCommonPipe, the simulation runs with the VS pump.

    PlantLocation TankOutletPlantLoc = {LoopNum, TankOutletLoopSide, 1, 0};
    TankOutletPlantLoc.loop = &state.dataPlnt->PlantLoop(LoopNum);
    TankOutletPlantLoc.side = &state.dataPlnt->PlantLoop(LoopNum).LoopSide(TankOutletPlantLoc.loopSideNum);
    TankOutletPlantLoc.branch = &TankOutletPlantLoc.side->Branch(1);

    ManageTwoWayCommonPipe(state, TankOutletPlantLoc, TankAverageTemp);

I'm not saying it runs good since it's hard to know what good would look like, and the changes made in 11600 might be fine for now. But the simulation did run before with a VS pump? even if the model threw an error. I think this under initialized TankOutletPlantLoc local is the reason for the crash. I'm doing some testing now with my changes and #11600 changes to see if anything makes sense. I don't see any difference between the 2 simulations.

Testing my changs:

Testing PR #11600 branch: