Merge pull request #8101 from NREL/173380574_Issue8087

Support Electric Heating Coil with ASHRAE90VariableFan Capacity Control
NREL · Jul 2, 2020 · 7a28efb · 7a28efb · nrel-bot-2b · Jul 2, 2020
2 parents 2516c7e + d14936c
commit 7a28efb
Show file tree

Hide file tree

Showing 7 changed files with 7,008 additions and 4,259 deletions.
diff --git a/src/EnergyPlus/FanCoilUnits.cc b/src/EnergyPlus/FanCoilUnits.cc
@@ -3104,15 +3104,19 @@ namespace FanCoilUnits {
                                                    PLR,
                                                    CompressorOnFlag);
                     }
-                }
-                Calc4PipeFanCoil(state, FanCoilNum, ControlledZoneNum, FirstHVACIteration, QUnitOut);
+                } else if ((CoolingLoad && QUnitOutMax > QZnReq && QZnReq < 0.0) || (HeatingLoad && QUnitOutMax < QZnReq && QZnReq > 0.0)) {
+                    // load is larger than capacity, thus run the fancoil unit at full capacity
+                    PLR = 1.0;
+                } 
+                Calc4PipeFanCoil(state, FanCoilNum, ControlledZoneNum, FirstHVACIteration, QUnitOut, PLR);
                 PowerMet = QUnitOut;
                 AirMassFlow = Node(InletNode).MassFlowRate;
                 // CR9155 Remove specific humidity calculations
                 SpecHumOut = Node(OutletNode).HumRat;
                 SpecHumIn = Node(InletNode).HumRat;
                 // Latent rate (kg/s), dehumid = negative
                 LatOutputProvided = AirMassFlow * (SpecHumOut - SpecHumIn);
+                FanCoil(FanCoilNum).PLR = PLR;
 
                 // cycling fan constant water flow AND VarFanVarFlow
             } else if (SELECT_CASE_var == CCM_VarFanConsFlow) {

diff --git a/src/EnergyPlus/SZVAVModel.cc b/src/EnergyPlus/SZVAVModel.cc
@@ -86,6 +86,7 @@ namespace SZVAVModel {
 
     // MODULE PARAMETER DEFINITIONS
     static std::string const BlankString;
+    int const HCoil_Water(1);
 
     // Functions
 
@@ -772,8 +773,11 @@ namespace SZVAVModel {
                         Par(9) = lowWaterMdot; // minCoilFluidFlow - low fan speed water flow rate > 0 if SAT limited
                         Par(12) = AirMassFlow; // sets air flow rate used when iterating on coil capacity
                         Par(13) = 0.0;         // other than 0 means to iterate on SA temperature
-
-                        TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilWaterFlowResidual, 0.0, 1.0, Par);
+                        if (SZVAVModel.HCoilType_Num == HCoil_Water || !HeatingLoad) {
+                            TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilWaterFlowResidual, 0.0, 1.0, Par);
+                        } else {
+                            TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilLoadResidual, 0.0, 1.0, Par);
+                        }
                         outletTemp = DataLoopNode::Node(OutletNode).Temp;
                         if ((CoolingLoad && outletTemp < maxOutletTemp) || (HeatingLoad && outletTemp > maxOutletTemp)) {
                             // must do something here to maintain outlet temp while in Region 2
@@ -784,20 +788,32 @@ namespace SZVAVModel {
                     } else { // not enough capacity at this air flow rate. Unit does have enough capacity a full water/air, otherwise wouldn't be here
                         // this is different from the PTUnit and UnitarySys routines in this module
                         // find the water flow rate that meets the min load at region 1/2 bounday
-                        TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, lowWaterMdot, FanCoilUnits::CalcFanCoilWaterFlowResidual, 0.0, 1.0, Par);
-                        Par(9) = lowWaterMdot;
-                        if (SolFlag < 0) {
-                            MessagePrefix = "Step 2a: ";
+                        if (SZVAVModel.HCoilType_Num == HCoil_Water || !HeatingLoad) {
+                            TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, lowWaterMdot, FanCoilUnits::CalcFanCoilWaterFlowResidual, 0.0, 1.0, Par);
+                            Par(9) = lowWaterMdot;
+                            if (SolFlag < 0) {
+                                MessagePrefix = "Step 2a: ";
+                            } else {
+                                Par(9) = 0.0;
+                            }
+                            TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilAirAndWaterFlowResidual, 0.0, 1.0, Par);
+                            if (SolFlag < 0) {
+                                MessagePrefix = "Step 2b: ";
+                            }
                         } else {
-                            Par(9) = 0.0;
-                        }
-                        TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilAirAndWaterFlowResidual, 0.0, 1.0, Par);
-                        if (SolFlag < 0) {
-                            MessagePrefix = "Step 2b: ";
+                            TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilLoadResidual, 0.0, 1.0, Par);
+                            if (SolFlag < 0) {
+                                MessagePrefix = "Step 2: ";
+                            }
                         }
                     }
                 } else { // too much capacity when coil off, could lower air flow rate here to meet load if air flow is above minimum
-                    TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilAirAndWaterFlowResidual, 0.0, 1.0, Par);
+                    if (SZVAVModel.HCoilType_Num == HCoil_Water || !HeatingLoad) {
+                        TempSolveRoot::SolveRoot(
+                            state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilAirAndWaterFlowResidual, 0.0, 1.0, Par);
+                    } else {
+                        TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilLoadResidual, 0.0, 1.0, Par);
+                    }
                     if (SolFlag < 0) {
                         MessagePrefix = "Step 2c: ";
                     }
@@ -855,12 +871,20 @@ namespace SZVAVModel {
                     // otherwise iterate on load
                     Par(12) = maxAirMassFlow; // operating air flow rate, minAirMassFlow indicates low speed, maxAirMassFlow indicates full speed
                     Par(13) = 0.0;            // SA Temp target, 0 means iterate on load and not SA temperature
-                    TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilWaterFlowResidual, 0.0, 1.0, Par);
+                    if (SZVAVModel.HCoilType_Num == HCoil_Water || !HeatingLoad) {
+                        TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilWaterFlowResidual, 0.0, 1.0, Par);
+                    } else {
+                        TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilLoadResidual, 0.0, 1.0, Par);
+                    }
                     if (SolFlag < 0) {
                         MessagePrefix = "Step 3: ";
                     }
                 } else { // too much capacity at full air flow with coil off, operate coil and fan in unison
-                    TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilAirAndWaterFlowResidual, 0.0, 1.0, Par);
+                    if (SZVAVModel.HCoilType_Num == HCoil_Water || !HeatingLoad) {
+                        TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilAirAndWaterFlowResidual, 0.0, 1.0, Par);
+                    } else {
+                        TempSolveRoot::SolveRoot(state, 0.001, MaxIter, SolFlag, PartLoadRatio, FanCoilUnits::CalcFanCoilLoadResidual, 0.0, 1.0, Par);
+                    }
                     if (SolFlag < 0) {
                         MessagePrefix = "Step 3a: ";
                     }

diff --git a/src/EnergyPlus/SZVAVModel.hh b/src/EnergyPlus/SZVAVModel.hh
@@ -77,7 +77,7 @@ namespace SZVAVModel {
     // parts of the simulation.
 
     // MODULE PARAMETER DEFINITIONS
-    // na
+    extern int const HCoil_Water;
 
     // DERIVED TYPE DEFINITIONS
     // na

diff --git a/testfiles/CMakeLists.txt b/testfiles/CMakeLists.txt
@@ -261,6 +261,7 @@ ADD_SIMULATION_TEST(IDF_FILE ExhFiredAbsorptionChiller.idf EPW_FILE USA_IL_Chica
 ADD_SIMULATION_TEST(IDF_FILE ExteriorLightsAndEq.idf EPW_FILE USA_CO_Golden-NREL.724666_TMY3.epw)
 ADD_SIMULATION_TEST(IDF_FILE FanCoilAutoSize.idf EPW_FILE USA_CO_Golden-NREL.724666_TMY3.epw)
 ADD_SIMULATION_TEST(IDF_FILE FanCoilAutoSizeScalableSizing.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
+ADD_SIMULATION_TEST(IDF_FILE FanCoilAutoSize_ASHRAE90VariableFan.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
 ADD_SIMULATION_TEST(IDF_FILE FanCoilAutoSize_MultiSpeedFan.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
 ADD_SIMULATION_TEST(IDF_FILE FanCoil_HybridVent_VentSch.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)
 ADD_SIMULATION_TEST(IDF_FILE Fault_ChillerSWTSensorOffset_RefBldgLargeOfficeNew2004.idf EPW_FILE USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw)