Skip to content

Set flow to 0 when load is 0 for air-source HeatPump:PlantLoop:EIR:* #11602

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
lymereJ wants to merge 7 commits into
base: develop
Choose a base branch
from
Open

Set flow to 0 when load is 0 for air-source HeatPump:PlantLoop:EIR:* #11602

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
c94f9dd
For AWHP, if no load then no flow.
lymereJ May 22, 2026
9d7a17d
Flow is expected when companion HP is used for HR.
lymereJ May 22, 2026
dc6abf3
Account for series config.
lymereJ May 23, 2026
c835e27
Adjust consideration for series configuration, edit unit test, and ad…
lymereJ May 26, 2026
8de2a4f
Add file to CMakeLists for PlantLoopHeatPump_EIR_AirSource_Parallel.i…
lymereJ May 26, 2026
d5ec12d
Exclude SP controls.
lymereJ May 26, 2026
a5e4b9c
Formatting.
lymereJ May 26, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 13 additions & 3 deletions src/EnergyPlus/PlantLoopHeatPumpEIR.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -298,8 +298,18 @@ void EIRPlantLoopHeatPump::setOperatingFlowRatesASHP(EnergyPlusData &state, bool
// Set flows if the heat pump is running
} else { // the heat pump must run
// apply min/max operating limits based on source side entering fluid temperature
if ((this->minSourceTempLimit > this->sourceSideInletTemp || this->maxSourceTempLimit < this->sourceSideInletTemp) &&
!this->heatRecoveryIsActive) {
// or if parallel configuration and no/very small load, the unit is turned off
bool tempOutOfRange = this->minSourceTempLimit > this->sourceSideInletTemp || this->maxSourceTempLimit < this->sourceSideInletTemp;
auto &comp = DataPlant::CompData::getPlantComponent(state, this->loadSidePlantLoc);
bool loadIndicator = false;
if (this->sysControlType == ControlType::Setpoint) {
Real64 leavingSetpoint = this->getLoadSideOutletSetPointTemp(state);
loadIndicator = std::abs(leavingSetpoint - this->loadSideInletTemp) < HVAC::SmallTempDiff;
} else {
loadIndicator = std::abs(currentLoad) < HVAC::SmallLoad;
}
bool lowLoadCondition = loadIndicator && comp.FlowCtrl != DataBranchAirLoopPlant::ControlType::SeriesActive;
if ((tempOutOfRange || lowLoadCondition) && !this->heatRecoveryAvailable) {
Comment on lines +303 to +312
Copy link
Copy Markdown
Collaborator Author

@lymereJ lymereJ May 27, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Revised approach to: 1) ensure equipment in series maintains flow even with no load, and 2) allow flow to pass through the unit when heat recovery is available.

this->loadSideMassFlowRate = 0.0;
this->sourceSideMassFlowRate = 0.0;
this->running = false;
Expand Down Expand Up @@ -2926,7 +2936,7 @@ void EIRFuelFiredHeatPump::doPhysics(EnergyPlusData &state, Real64 currentLoad)
// get setpoint on the load side outlet
// Real64 loadSideOutletSetpointTemp = this->getLoadSideOutletSetPointTemp(state);

// Use a logic similar to that for a boilder: If the specified load is 0.0 or the boiler should not run
// Use a logic similar to that for a boiler: If the specified load is 0.0 or the boiler should not run
// then we leave this subroutine. Before leaving
// if the component control is SERIESACTIVE we set the component flow to inlet flow so that flow resolver
// will not shut down the branch
Expand Down
1 change: 1 addition & 0 deletions testfiles/CMakeLists.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -465,6 +465,7 @@ add_simulation_test(IDF_FILE PlantLoopChainDeadband.idf EPW_FILE USA_IL_Chicago-
add_simulation_test(IDF_FILE PlantLoopChainDualDeadband.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
add_simulation_test(IDF_FILE PlantLoopChainHeating.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
add_simulation_test(IDF_FILE PlantLoopHeatPump_EIR_AirSource.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
add_simulation_test(IDF_FILE PlantLoopHeatPump_EIR_AirSource_Parallel.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
Copy link
Copy Markdown
Collaborator Author

@lymereJ lymereJ May 27, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

As requested, this is a new test file, based on PlantLoopHeatPump_EIR_AirSource.idf, that includes AWHPs in parallel (only one AWHP is used in PlantLoopHeatPump_EIR_AirSource.idf).

When running this file with develop we see that AWHP HEATING COIL 2 has flow even when it does not provide any heating:

Image

With this branch, we only see flow when the AWHP is providing heating:

Image

add_simulation_test(IDF_FILE PlantLoopHeatPump_EIR_AirSource_BufferTank.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
add_simulation_test(IDF_FILE PlantLoopHeatPump_EIR_WaterSource.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
add_simulation_test(IDF_FILE PlantLoopHeatPump_Fuel-Fired.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
Expand Down
Loading
Loading