Fix VRF_FluidTCtrl cooling supply fan power calculation when cycling

doc/input-output-reference/src/overview/group-zone-forced-air-units.tex

@@ -4060,7 +4060,7 @@ \subsubsection{Inputs}\label{inputs-14-018}
 
 \paragraph{Field: Supply Air Fan Object Type}\label{field-supply-air-fan-object-type-8}
 
-This choice field contains the identifying type of supply air fan specified for the furnace. Fan type must be \textit{\hyperref[fanonoff]{Fan:OnOff}}, \textit{\hyperref[fanconstantvolume]{Fan:ConstantVolume}}, \textit{\hyperref[fansystemmodel]{Fan:SystemModel}} or \textit{\hyperref[fanvariablevolume]{Fan:VariableVolume}}. The Supply Air Fan Object Type must be \hyperref[fansystemmodel]{Fan:SystemModel}, \hyperref[fanonoff]{Fan:OnOff}, or \hyperref[fanconstantvolume]{Fan:ConstantVolume} if \hyperref[airconditionervariablerefrigerantflow]{AirConditioner:VariableRefrigerantFlow} is used to model the VRF outdoor unit. The Supply Air Fan Object Type must be \hyperref[fansystemmodel]{Fan:SystemModel} or \hyperref[fanvariablevolume]{Fan:VariableVolume} if AirConditioner:VariableRefrigerantFlow:\-FluidTemperatureControl or AirConditioner:VariableRefrigerantFlow:\-FluidTemperatureControl:HR is used to model the VRF outdoor unit.
+This choice field contains the identifying type of supply air fan specified for the furnace. Fan type must be \textit{\hyperref[fanonoff]{Fan:OnOff}}, \textit{\hyperref[fanconstantvolume]{Fan:ConstantVolume}}, \textit{\hyperref[fansystemmodel]{Fan:SystemModel}}. The Supply Air Fan Object Type must be \hyperref[fansystemmodel]{Fan:SystemModel}, \hyperref[fanonoff]{Fan:OnOff}, or \hyperref[fanconstantvolume]{Fan:ConstantVolume} if \hyperref[airconditionervariablerefrigerantflow]{AirConditioner:VariableRefrigerantFlow} is used to model the VRF outdoor unit. The Supply Air Fan Object Type must be \hyperref[fansystemmodel]{Fan:SystemModel} if AirConditioner:VariableRefrigerantFlow:\-FluidTemperatureControl or AirConditioner:VariableRefrigerantFlow:\-FluidTemperatureControl:HR is used to model the VRF outdoor unit.
 
 \hyperref[fanconstantvolume]{Fan:ConstantVolume} is used when the Supply Air Fan Operating Mode Schedule values are never 0 and the fan operates continuously. \hyperref[fanonoff]{Fan:OnOff} is used when the fan cycles on and off with the cooling or heating coil (i.e.~Supply Air Fan Operating Mode Schedule values are at times 0). The \hyperref[fansystemmodel]{Fan:SystemModel} may be used to model either of these fan operating characteristics.
 

idd/Energy+.idd.in

@@ -42466,11 +42466,10 @@ ZoneHVAC:TerminalUnit:VariableRefrigerantFlow,
         \key Fan:SystemModel
         \key Fan:OnOff
         \key Fan:ConstantVolume
-        \key Fan:VariableVolume
         \default Fan:ConstantVolume
         \note Supply Air Fan Object Type must be Fan:SystemModel, Fan:OnOff, or Fan:ConstantVolume
         \note if AirConditioner:VariableRefrigerantFlow is used to model VRF outdoor unit
-        \note Supply Air Fan Object Type must be Fan:SystemModel or Fan:VariableVolume if
+        \note Supply Air Fan Object Type must be Fan:SystemModel if
         \note AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl or
         \note AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl:HR
         \note is used to model VRF outdoor unit

src/EnergyPlus/HVACVariableRefrigerantFlow.cc

@@ -5494,7 +5494,7 @@ void CheckVRFTUNodeConnections(EnergyPlusData &state, int const VRFTUNum, bool &
         if (fanOutletNode != VRFTUOutletNodeNum) {
             ShowSevereError(state, fmt::format("{}=\"{}\",", cTerminalUnitType, cTUName));
             ShowContinueError(state,
-                              "... For blow through fan and no supplemental heating coil the fan outlet node name must "
+                              "... For draw through fan and no supplemental heating coil the fan outlet node name must "
                               "match the terminal unit outlet node name.");
             if (fanOutletNode > 0 && VRFTUOutletNodeNum > 0) {
                 ShowContinueError(state, format("... Fan outlet node name = {}.", nodeID(fanOutletNode)));
@@ -12841,12 +12841,16 @@ void VRFTerminalUnitEquipment::CalcVRF_FluidTCtrl(EnergyPlusData &state,
         state.dataHVACVarRefFlow->LoopDXHeatCoilRTF = 0.0;
     }
 
+    Real64 OnOffFanPartLoadFraction = 1.0;
+    if (state.dataHVACVarRefFlow->VRFTU(VRFTUNum).fanOp == HVAC::FanOp::Cycling) {
+        OnOffFanPartLoadFraction = state.dataHVACGlobal->OnOffFanPartLoadFraction;
+    }
     // if draw through, simulate coils then fan
     if (this->fanPlace == HVAC::FanPlace::DrawThru) {
         auto *fan = state.dataFans->fans(state.dataHVACVarRefFlow->VRFTU(VRFTUNum).FanIndex);
         if (state.dataHVACVarRefFlow->VRFTU(VRFTUNum).fanType == HVAC::FanType::SystemModel) {
             if (OnOffAirFlowRatio > 0.0) {
-                fan->simulate(state, FirstHVACIteration, _, _);
+                fan->simulate(state, FirstHVACIteration, _, _, _, fan->inletAirMassFlowRate, OnOffFanPartLoadFraction, 0, 0, _);
             } else {
                 fan->simulate(state, FirstHVACIteration, _, _, PartLoadRatio);
             }

src/Transition/CreateNewIDFUsingRulesV24_2_0.f90

@@ -124,6 +124,42 @@ SUBROUTINE CreateNewIDFUsingRules(EndOfFile,DiffOnly,InLfn,AskForInput,InputFile
 !                                     I N S E R T    L O C A L    V A R I A B L E S    H E R E                                     !
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
+  ! used in transition code for changing fan in ZoneHVAC:TerminalUnit:VariableRefrigerantFlow from VariableVolume to SystemModel
+  LOGICAL :: isVariableVolume
+  REAL :: fanTotalEff
+  REAL :: pressureRise
+  REAL :: maxAirFlow
+  REAL :: minAirFlowFrac
+  REAL :: fanPowerMinAirFlow
+  INTEGER :: NumFanVariableVolume
+  INTEGER :: NumOldFanVO = 1
+  INTEGER :: NumVRFTU = 1
+  INTEGER :: Num3 = 1
+  INTEGER :: VRFTU_i = 1
+  CHARACTER(len=MaxNameLength) :: sysFanName
+  CHARACTER(len=MaxNameLength), ALLOCATABLE, DIMENSION(:) :: vavFanNameToDelete
+
+  TYPE FanVOTransitionInfo
+    CHARACTER(len=MaxNameLength) :: oldFanName
+    CHARACTER(len=MaxNameLength) :: availSchedule
+    CHARACTER(len=MaxNameLength) :: fanTotalEff_str
+    CHARACTER(len=MaxNameLength) :: pressureRise_str
+    CHARACTER(len=MaxNameLength) :: maxAirFlow_str
+    CHARACTER(len=MaxNameLength) :: minFlowInputMethod
+    CHARACTER(len=MaxNameLength) :: minAirFlowFrac_str
+    CHARACTER(len=MaxNameLength) :: fanPowerMinAirFlow_str
+    CHARACTER(len=MaxNameLength) :: motorEfficiency
+    CHARACTER(len=MaxNameLength) :: motorInAirStreamFrac
+    CHARACTER(len=MaxNameLength) :: coeff1             !- Coefficient1 Constant
+    CHARACTER(len=MaxNameLength) :: coeff2             !- Coefficient2 x
+    CHARACTER(len=MaxNameLength) :: coeff3             !- Coefficient3 x**2
+    CHARACTER(len=MaxNameLength) :: coeff4             !- Coefficient4 x**3
+    CHARACTER(len=MaxNameLength) :: coeff5             !- Coefficient5 x**4
+    CHARACTER(len=MaxNameLength) :: inletAirNodeName
+    CHARACTER(len=MaxNameLength) :: outletAirNodeName
+    CHARACTER(len=MaxNameLength) :: endUseSubCat
+  END TYPE FanVOTransitionInfo
+  TYPE(FanVOTransitionInfo), ALLOCATABLE, DIMENSION(:) :: OldFanVO
 
   INTEGER :: TotSPMs = 0
   INTEGER :: spmNum = 0
@@ -317,6 +353,55 @@ SUBROUTINE CreateNewIDFUsingRules(EndOfFile,DiffOnly,InLfn,AskForInput,InputFile
               ENDDO
           ENDDO
 
+          ! collect old VAV fans to be deleted
+          NumVRFTU = GetNumObjectsFound('ZONEHVAC:TERMINALUNIT:VARIABLEREFRIGERANTFLOW')
+          IF(ALLOCATED(vavFanNameToDelete)) DEALLOCATE(vavFanNameToDelete)
+          ALLOCATE(vavFanNameToDelete(NumVRFTU))
+          DO Num = 1, NumIDFRecords
+            SELECT CASE (MakeUPPERCase(IDFRecords(Num)%Name))
+            CASE('ZONEHVAC:TERMINALUNIT:VARIABLEREFRIGERANTFLOW')
+              IF (SameString(TRIM(IDFRecords(Num)%Alphas(7)), 'FAN:VARIABLEVOLUME')) THEN
+                vavFanNameToDelete(VRFTU_i) =TRIM(IDFRecords(Num)%Alphas(8))
+              ELSE
+                vavFanNameToDelete(VRFTU_i) = ''
+              ENDIF
+              VRFTU_i = VRFTU_i + 1
+            END SELECT
+          END DO
+
+          ! accumulate info on VAV fans
+          NumFanVariableVolume = GetNumObjectsFound('FAN:VARIABLEVOLUME')
+          IF (ALLOCATED(OldFanVO)) DEALLOCATE(OldFanVO)
+          ALLOCATE(OldFanVO(NumFanVariableVolume))
+          NumOldFanVO = 1
+          DO Num = 1, NumIDFRecords
+            SELECT CASE (MakeUPPERCase(IDFRecords(Num)%Name))
+            CASE ('FAN:VARIABLEVOLUME')
+              OldFanVO(NumOldFanVO)%oldFanName = TRIM(IDFRecords(Num)%Alphas(1))
+              OldFanVO(NumOldFanVO)%availSchedule = TRIM(IDFRecords(Num)%Alphas(2))
+              OldFanVO(NumOldFanVO)%fanTotalEff_str = TRIM(IDFRecords(Num)%Numbers(1))
+              OldFanVO(NumOldFanVO)%pressureRise_str = TRIM(IDFRecords(Num)%Numbers(2))
+              OldFanVO(NumOldFanVO)%maxAirFlow_str = TRIM(IDFRecords(Num)%Numbers(3))
+              OldFanVO(NumOldFanVO)%minFlowInputMethod = TRIM(IDFRecords(Num)%Alphas(3))
+              OldFanVO(NumOldFanVO)%minAirFlowFrac_str = TRIM(IDFRecords(Num)%Numbers(4))
+              OldFanVO(NumOldFanVO)%fanPowerMinAirFlow_str = TRIM(IDFRecords(Num)%Numbers(5))
+              OldFanVO(NumOldFanVO)%motorEfficiency = TRIM(IDFRecords(Num)%Numbers(6))
+              OldFanVO(NumOldFanVO)%motorInAirStreamFrac = TRIM(IDFRecords(Num)%Numbers(7))
+              OldFanVO(NumOldFanVO)%coeff1 = TRIM(IDFRecords(Num)%Numbers(8))              !- Coefficient1 Constant
+              OldFanVO(NumOldFanVO)%coeff2 = TRIM(IDFRecords(Num)%Numbers(9))              !- Coefficient2 x
+              OldFanVO(NumOldFanVO)%coeff3 = TRIM(IDFRecords(Num)%Numbers(10))             !- Coefficient3 x**2
+              OldFanVO(NumOldFanVO)%coeff4 = TRIM(IDFRecords(Num)%Numbers(11))             !- Coefficient4 x**3
+              OldFanVO(NumOldFanVO)%coeff5 = TRIM(IDFRecords(Num)%Numbers(12))             !- Coefficient5 x**4
+              OldFanVO(NumOldFanVO)%inletAirNodeName = TRIM(IDFRecords(Num)%Alphas(4))
+              OldFanVO(NumOldFanVO)%outletAirNodeName = TRIM(IDFRecords(Num)%Alphas(5))
+              OldFanVO(NumOldFanVO)%endUseSubCat = TRIM(IDFRecords(Num)%Alphas(6))
+              IF (FindItemInList(TRIM(IDFRecords(Num)%Alphas(1)), vavFanNameToDelete, NumVRFTU) /= 0) THEN
+                DeleteThisRecord(Num) = .TRUE.
+              ENDIF
+              NumOldFanVO = NumOldFanVO + 1
+            END SELECT
+          END DO
+
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 !                                                       P R O C E S S I N G                                                        !
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
@@ -485,6 +570,104 @@ SUBROUTINE CreateNewIDFUsingRules(EndOfFile,DiffOnly,InLfn,AskForInput,InputFile
 
               ! If your original object starts with Z, insert the rules here
 
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+              CASE('ZONEHVAC:TERMINALUNIT:VARIABLEREFRIGERANTFLOW')
+                isVariableVolume = .FALSE.
+                CALL GetNewObjectDefInIDD(ObjectName, NwNumArgs, NwAorN, NwReqFld, NwObjMinFlds, NwFldNames, NwFldDefaults, NwFldUnits)
+                nodiff = .false.
+                OutArgs(1:13) = InArgs(1:13)
+                IF (SameString(InArgs(14), 'FAN:VARIABLEVOLUME')) THEN
+                  isVariableVolume = .TRUE.
+                  OutArgs(14) = 'Fan:SystemModel'
+                  OutArgs(15) = TRIM(InArgs(15))
+                  sysFanName = TRIM(InArgs(15))
+                ELSE
+                  OutArgs(14:15) = InArgs(14:15)
+                ENDIF
+                OutArgs(16:CurArgs) = InArgs(16:CurArgs)
+                CALL WriteOutIDFLines(DifLfn, 'ZoneHVAC:TerminalUnit:VariableRefrigerantFlow', CurArgs, OutArgs, NwFldNames, NwFldUnits)
+
+                IF (isVariableVolume) THEN
+                  ! create fan system model object
+                  ObjectName = 'Fan:SystemModel'
+                  DO Num3 = 1, NumFanVariableVolume
+                    IF (SameString(OldFanVO(Num3)%oldFanName, sysFanName)) THEN
+                      CALL GetNewObjectDefInIDD(ObjectName, NwNumArgs, NwAorN, NwReqFld, NwObjMinFlds, NwFldNames, NwFldDefaults, NwFldUnits)
+                      OutArgs(1) = TRIM(sysFanName)
+                      OutArgs(2) = OldFanVO(Num3)%availSchedule
+                      OutArgs(3) = OldFanVO(Num3)%inletAirNodeName
+                      OutArgs(4) = OldFanVO(Num3)%outletAirNodeName
+                      OutArgs(5) = OldFanVO(Num3)%maxAirFlow_str
+                      OutArgs(6) = 'Continuous'                             !- Speed Control Method
+                      IF (SameString(OldFanVO(Num3)%minFlowInputMethod, "FixedFlowRate")) THEN
+                        IF (.NOT. SameString(OldFanVO(Num3)%maxAirFlow_str, "AUTOSIZE")) THEN
+                          fanPowerMinAirFlow = ProcessNumber(OldFanVO(Num3)%fanPowerMinAirFlow_str, ErrFlag)
+                          IF (ErrFlag) THEN
+                            CALL ShowSevereError('Invalid Number, FAN:VARIABLEVOLUME field 8, Fan Power Minimum Air Flow Rate, Name=' // TRIM(OutArgs(1)), Auditf)
+                          END IF
+                          maxAirFlow = ProcessNumber(OldFanVO(Num3)%maxAirFlow_str, ErrFlag)
+                          IF (ErrFlag) THEN
+                            CALL ShowSevereError('Invalid Number, FAN:VARIABLEVOLUME field 5, Maximum Flow Rate, Name=' // TRIM(OutArgs(1)), Auditf)
+                          END IF
+                          WRITE(OutArgs(7), '(F15.5)') (fanPowerMinAirFlow / maxAirFlow)
+                      ELSE ! maxAirFlow_stris autosize
+                          fanPowerMinAirFlow = ProcessNumber(OldFanVO(Num3)%fanPowerMinAirFlow_str, ErrFlag)
+                          IF (ErrFlag) THEN
+                            CALL ShowSevereError('Invalid Number, FAN:VARIABLEVOLUME field 8, Fan Power Minimum Air Flow Rate, Name=' // TRIM(OutArgs(1)), Auditf)
+                          END IF
+                          IF (.NOT. fanPowerMinAirFlow == 0) THEN ! don't know how to do division with autosize
+                            CALL writePreprocessorObject(DifLfn, PrognameConversion, 'Warning', &
+                                    'Cannot calculate Electric Power Minimum Flow Rate Fraction for Fan:SystemModel=' // sysFanName // &
+                                            ' when old Fan:VariableVolume Maximum Flow Rate is autosize and Fan Power Minimum Air Flow Rate is non-zero. ' // &
+                                            'Electric Power Minimum Flow Rate Fraction is set to zero. ' // &
+                                            'Manually size the Maximum Flow Rate if Electric Power Minimum Flow Rate Fraction should not be zero.')
+                            CALL ShowWarningError('Cannot calculate Electric Power Minimum Flow Rate Fraction for Fan:SystemModel=' // sysFanName // &
+                                    ' when old Fan:VariableVolume Maximum Flow Rate is autosize and Fan Power Minimum Air Flow Rate is non-zero. ' // &
+                                    'Electric Power Minimum Flow Rate Fraction is set to zero. ' // &
+                                    'Manually size the Maximum Flow Rate if Electric Power Minimum Flow Rate Fraction should not be zero.', Auditf)
+                          END IF
+                          OutArgs(7) = '0.0'
+                        ENDIF
+                      ELSE ! input method is "Fraction"
+                        OutArgs(7) = OldFanVO(Num3)%minAirFlowFrac_str
+                      ENDIF
+                      OutArgs(8) = OldFanVO(Num3)%pressureRise_str          !- Design Pressure Rise {Pa}
+                      OutArgs(9) = OldFanVO(Num3)%motorEfficiency           !- Motor Efficiency
+                      OutArgs(10) = OldFanVO(Num3)%motorInAirStreamFrac     !- Motor In Air Stream Fraction
+                      OutArgs(11) = 'autosize'
+                      OutArgs(12) = 'TotalEfficiencyAndPressure' ! chose this becuase power per flow or per pressure are unknown
+                      OutArgs(13) = ''                       !- Electric Power Per Unit Flow Rate {W/(m3/s)}
+                      OutArgs(14) = ''                       !- Electric Power Per Unit Flow Rate Per Unit Pressure {W/((m3/s)-Pa)}
+                      OutArgs(15) = OldFanVO(Num3)%fanTotalEff_str          !- Fan Total Efficiency
+                      OutArgs(16) = TRIM(sysFanName) // '_curve'    !- Electric Power Function of Flow Fraction Curve Name
+                      OutArgs(17) = ''
+                      OutArgs(18) = ''
+                      OutArgs(19) = ''
+                      OutArgs(20) = ''
+                      OutArgs(21) = OldFanVO(Num3)%endUseSubCat !- End-Use Subcategory
+                      CurArgs = 21                           !- Design Electric Power Consumption {W}
+                      CALL WriteOutIDFLines(DifLfn, ObjectName, CurArgs, OutArgs, NwFldNames, NwFldUnits)
+
+                      ! create curve object
+                      ObjectName = 'Curve:Quartic'
+                      CALL GetNewObjectDefInIDD(ObjectName, NwNumArgs, NwAorN, NwReqFld, NwObjMinFlds, NwFldNames, NwFldDefaults, NwFldUnits)
+                      OutArgs(1) = TRIM(sysFanName) // '_curve'
+                      OutArgs(2) = OldFanVO(Num3)%coeff1             !- Coefficient1 Constant
+                      OutArgs(3) = OldFanVO(Num3)%coeff2             !- Coefficient2 x
+                      OutArgs(4) = OldFanVO(Num3)%coeff3             !- Coefficient3 x**2
+                      OutArgs(5) = OldFanVO(Num3)%coeff4             !- Coefficient4 x**3
+                      OutArgs(6) = OldFanVO(Num3)%coeff5             !- Coefficient5 x**4
+                      OutArgs(7) = '0.0'              !- Minimum Value of x
+                      OutArgs(8) = '1.0'              !- Maximum Value of x
+                      OutArgs(9) = '0.0'              !- Minimum Curve Output
+                      OutArgs(10) = '5.0'             !- Maximum Curve Output
+                      OutArgs(11) = 'Dimensionless'   !- Input Unit Type for X
+                      OutArgs(12) = 'Dimensionless'   !- Output Unit Type
+                      CurArgs = 12
+                    ENDIF
+                  ENDDO
+                ENDIF
+
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 !                                   Changes for report variables, meters, tables -- update names                                   !
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

src/Transition/InputRulesFiles/Rules24-1-0-to-24-2-0.md

@@ -73,3 +73,11 @@ There are three new optional heat recovery fields at the end which transition wi
 # Object Change: ObjectStartsWithY
 
 # Object Change: ObjectStartsWithZ
+## "ZoneHVAC:TerminalUnit:VariableRefrigerantFlow"
+If field "Supply Air Fan Object Type" (A7, the 14th field) in
+"ZoneHVAC:TerminalUnit:VariableRefrigerantFlow" is "Fan:VariableVolume", it
+needs to be changed to "Fan:SystemModel". A "Fan:SystemModel" object need to be
+created based on the former "Fan:VariableVolume" object. A fan power curve will
+be created as well that holds the "Fan Power Coefficient i" in Fan:VariableVolume.
+
+See PR https://github.com/NREL/EnergyPlus/pull/10341