CalcCTGeneratorModel Subroutine

private subroutine CalcCTGeneratorModel(GeneratorNum, RunFlag, MyLoad, FirstHVACIteration)

Arguments

Type	Intent		Name
integer,	intent(in)	::	GeneratorNum
logical,	intent(in)	::	RunFlag
real(kind=r64),	intent(in)	::	MyLoad
logical,	intent(in)	::	FirstHVACIteration
Source Code

SUBROUTINE CalcCTGeneratorModel(GeneratorNum,Runflag,MyLoad,FirstHVACIteration)
          ! SUBROUTINE INFORMATION:
          !       AUTHOR         Dan Fisher
          !       DATE WRITTEN   Sept. 2000
          !       MODIFIED       na
          !       RE-ENGINEERED  na

          ! PURPOSE OF THIS SUBROUTINE:
          ! simulate a vapor compression Generator using the CT model

          ! METHODOLOGY EMPLOYED:
          ! curve fit of performance data.  This model was originally
          ! developed by Dale Herron for the BLAST program

          ! REFERENCES: na

          ! USE STATEMENTS:
  USE DataHVACGlobals, ONLY : FirstTimeStepSysFlag, TimeStepSys

  USE DataEnvironment, ONLY : OutDryBulbTemp
  USE CurveManager,    ONLY : CurveValue
  USE FluidProperties, ONLY : GetSpecificHeatGlycol
  USE DataPlant,       ONLY : PlantLoop

  IMPLICIT NONE


          ! SUBROUTINE ARGUMENT DEFINITIONS:
  REAL(r64)   , INTENT(IN)    :: MyLoad          ! Generator demand
  INTEGER, INTENT(IN)    :: GeneratorNum    ! Generator number
  LOGICAL, INTENT(IN)    :: RunFlag         ! TRUE when Generator operating
  LOGICAL, INTENT(IN)    :: FirstHVACIteration

          ! SUBROUTINE PARAMETER DEFINITIONS:
  REAL(r64), PARAMETER   :: ExhaustCP = 1.047d0    !Exhaust Gas Specific Heat (J/kg-K)
  REAL(r64), PARAMETER   :: KJtoJ = 1000.d0        !convert Kjoules to joules

          ! INTERFACE BLOCK SPECIFICATIONS
            ! INTERFACE

            !  REAL(r64) FUNCTION CurveValue(CurveIndex,Var1,Var2)
            !
            !    INTEGER, INTENT (IN)        :: CurveIndex  ! index of curve in curve array
            !    REAL(r64), INTENT (IN)           :: Var1        ! 1st independent variable
            !    REAL(r64), INTENT (IN), OPTIONAL :: Var2        ! 2nd independent variable
            !
            !  END FUNCTION CurveValue
            !
            ! END INTERFACE

          ! DERIVED TYPE DEFINITIONS
          ! na

          ! SUBROUTINE LOCAL VARIABLE DECLARATIONS:
  REAL(r64)         :: MinPartLoadRat      ! min allowed operating frac full load
  REAL(r64)         :: MaxPartLoadRat      ! max allowed operating frac full load
  REAL(r64)         :: RatedPowerOutput    ! Generator nominal capacity (W)
  REAL(r64)         :: ElecPowerGenerated  ! Generator output (W)
  REAL(r64)         :: ElectricEnergyGen   ! Generator output (J)

! Special variables for CT Generator
  REAL(r64)    :: MaxExhaustperCTPower   !MAX EXHAUST FLOW PER W POWER OUTPUT COEFF
  REAL(r64)    :: PLR                    ! Generator operating part load ratio
  REAL(r64)    :: FuelUseRate            !(EFUEL) rate of Fuel Energy Required to run COMBUSTION turbine (W)
  REAL(r64)    :: FuelEnergyUsed         !Amount of Fuel Energy Required to run COMBUSTION turbine (J)
  REAL(r64)    :: ExhaustFlow            !(FEX) Exhaust Gas Flow Rate cubic meters per second???
  REAL(r64)    :: ExhaustTemp            !(TEX) Exhaust Gas Temperature in C
  REAL(r64)    :: UA             !(UACGC) Heat Exchanger UA to Capacity
  REAL(r64)    :: AmbientDeltaT          !(ATAIR) Difference between ambient actual and ambient design temperatures
  REAL(r64)    :: DesignAirInletTemp     ! design turbine inlet temperature (C)
  REAL(r64)    :: QLubeOilRec          ! recovered lube oil heat (W)
  REAL(r64)    :: QExhaustRec          ! recovered exhaust heat (W)
  REAL(r64)    :: LubeOilEnergyRec     ! recovered lube oil heat (J)
  REAL(r64)    :: ExhaustEnergyRec     ! recovered exhaust heat (J)
  REAL(r64)    :: MinHeatRecMdot       ! Heat Recovery Flow Rate if minimal heat recovery is accomplished
  REAL(r64)    :: DesignMinExitGasTemp     ! design engine stact saturated steam temp. (C)
  REAL(r64)    :: ExhaustStackTemp       ! turbine stack temp. (C)
  INTEGER :: HeatRecInNode          !Heat Recovery Fluid Inlet Node Num
!notused  INTEGER :: HeatRecOutNode         !Heat Recovery Fluid Outlet Node Num
  REAL(r64)    :: HeatRecInTemp          !Heat Recovery Fluid Inlet Temperature (C)
  REAL(r64)    :: HeatRecOutTemp         !Heat Recovery Fluid Outlet Temperature (C)
  REAL(r64)    :: HeatRecMdot            !Heat Recovery Fluid Mass FlowRate (kg/s)
  REAL(r64)    :: HeatRecCp              !Specific Heat of the Heat Recovery Fluid (J/kg-K)
  REAL(r64)    :: FuelHeatingValue       !Heating Value of Fuel in (kJ/kg)
  REAL(r64)    :: HRecRatio              !When Max Temp is reached the amount of recovered heat has to be reduced.
                                    ! and this assumption uses this ratio to accomplish this task.

          !  LOAD LOCAL VARIABLES FROM DATA STRUCTURE (for code readability)
  MinPartLoadRat       = CTGenerator(GeneratorNum)%MinPartLoadRat
  MaxPartLoadRat       = CTGenerator(GeneratorNum)%MaxPartLoadRat
  RatedPowerOutput     = CTGenerator(GeneratorNum)%RatedPowerOutput
  MaxExhaustperCTPower = CTGenerator(GeneratorNum)%MaxExhaustperCTPower
  DesignAirInletTemp   = CTGenerator(GeneratorNum)%DesignAirInletTemp
  IF (CTGenerator(GeneratorNum)%HeatRecActive) THEN
    HeatRecInNode        = CTGenerator(GeneratorNum)%HeatRecInletNodeNum
    HeatRecInTemp = Node(HeatRecInNode)%Temp

    HeatRecCp = GetSpecificHeatGlycol(PlantLoop(CTGenerator(GeneratorNum)%HRLoopNum)%FluidName, &
                             HeatRecInTemp, &
                             PlantLoop(CTGenerator(GeneratorNum)%HRLoopNum)%FluidIndex, &
                             'CalcCTGeneratorModel')
    If(FirstHVACIteration .AND. RunFlag) Then
       HeatRecMdot = CTGenerator(GeneratorNum)%DesignHeatRecMassFlowRate
    Else
       HeatRecMdot = Node(HeatRecInNode)%MassFlowRate
    End If
  ELSE
    HeatRecInTemp=0.0d0
    HeatRecCp=0.0d0
    HeatRecMdot=0.0d0
  ENDIF

        !If no loop demand or Generator OFF, return
  IF (.NOT. Runflag) THEN
    CTGenerator(GeneratorNum)%ElecPowerGenerated  = 0.0d0
    CTGenerator(GeneratorNum)%ElecEnergyGenerated  = 0.0d0
    CTGenerator(GeneratorNum)%HeatRecInletTemp    = HeatRecInTemp
    CTGenerator(GeneratorNum)%HeatRecOutletTemp   = HeatRecInTemp
    CTGenerator(GeneratorNum)%HeatRecMdot         = 0.0d0
    CTGenerator(GeneratorNum)%QLubeOilRecovered   = 0.0d0
    CTGenerator(GeneratorNum)%QExhaustRecovered   = 0.0d0
    CTGenerator(GeneratorNum)%QTotalHeatRecovered   = 0.0d0
    CTGenerator(GeneratorNum)%LubeOilEnergyRec   = 0.0d0
    CTGenerator(GeneratorNum)%ExhaustEnergyRec  = 0.0d0
    CTGenerator(GeneratorNum)%TotalHeatEnergyRec  = 0.0d0
    CTGenerator(GeneratorNum)%FuelEnergyUseRate      = 0.0d0
    CTGenerator(GeneratorNum)%FuelEnergy     = 0.0d0
    CTGenerator(GeneratorNum)%FuelMdot      = 0.0d0
    CTGenerator(GeneratorNum)%ExhaustStackTemp    = 0.0d0
    RETURN
  END IF


    ! CALCULATE POWER GENERATED AND PLR
  ElecPowerGenerated = MIN(MyLoad,RatedPowerOutput)
  ElecPowerGenerated = MAX(ElecPowerGenerated,0.0d0)
  PLR = MIN(ElecPowerGenerated/RatedPowerOutput, MaxPartLoadRat)
  PLR = MAX(PLR, MinPartLoadRat)
  ElecPowerGenerated = PLR*RatedPowerOutput


    ! SET OFF-DESIGN AIR TEMPERATURE DIFFERENCE
    !   use OA node if set by user CR7021
  If  (CTGenerator(GeneratorNum)%OAInletNode == 0) then
    AmbientDeltaT = OutDryBulbTemp - DesignAirInletTemp
  ELSE
    AmbientDeltaT = Node(CTGenerator(GeneratorNum)%OAInletNode)%Temp - DesignAirInletTemp
  ENDIF


!Use Curve fit to determine Fuel Energy Input.  For electric power generated in Watts, the fuel
!energy input is calculated in J/s.  The PLBasedFuelInputCurve selects ratio of fuel flow (J/s)/power generated (J/s).
!The TempBasedFuelInputCurve is a correction based on deviation from design inlet air temperature conditions.
!The first coefficient of this fit should be 1.0 to ensure that no correction is made at design conditions.
  FuelUseRate = ElecPowerGenerated * CurveValue(CTGenerator(GeneratorNum)%PLBasedFuelInputCurve, PLR)  * &
                                      CurveValue(CTGenerator(GeneratorNum)%TempBasedFuelInputCurve, AmbientDeltaT)

!Use Curve fit to determine Exhaust Flow.  This curve shows the ratio of exhaust gas flow (kg/s) to electric power
!output (J/s).  The units on ExhaustFlowCurve are (kg/J).  When multiplied by the rated power of the unit,
!it gives the exhaust flow rate in kg/s
  ExhaustFlow = RatedPowerOutput * CurveValue(CTGenerator(GeneratorNum)%ExhaustFlowCurve, AmbientDeltaT)

!Use Curve fit to determine Exhaust Temperature.  This curve calculates the exhaust temperature (C) by
!multiplying the exhaust temperature (C) for a particular part load as given by PLBasedExhaustTempCurve
!a correction factor based on the deviation from design temperature, TempBasedExhaustTempCurve
  IF ((PLR > 0.0d0) .AND. ( (ExhaustFlow > 0.0D0) .or. (MaxExhaustperCTPower > 0.0D0))) THEN

    ExhaustTemp = CurveValue(CTGenerator(GeneratorNum)%PLBasedExhaustTempCurve, PLR)  * &
                  CurveValue(CTGenerator(GeneratorNum)%TempBasedExhaustTempCurve, AmbientDeltaT)

    UA = CTGenerator(GeneratorNum)%UACoef(1) * RatedPowerOutput **  &
                   CTGenerator(GeneratorNum)%UACoef(2)

    DesignMinExitGasTemp = CTGenerator(GeneratorNum)%DesignMinExitGasTemp
    ExhaustStackTemp = DesignMinExitGasTemp + (ExhaustTemp - DesignMinExitGasTemp) / &
                         EXP(UA/(MAX(ExhaustFlow, MaxExhaustperCTPower * RatedPowerOutput) * ExhaustCP))

    QExhaustRec = MAX(ExhaustFlow*ExhaustCP*(ExhaustTemp-ExhaustStackTemp),0.0d0)
  ELSE
    ExhaustStackTemp = CTGenerator(GeneratorNum)%DesignMinExitGasTemp
    QExhaustRec = 0.0d0
  END IF

!Use Curve fit to determine Heat Recovered Lubricant heat.  This curve calculates the lube heat recovered (J/s) by
!multiplying the total power generated by the fraction of that power that could be recovered in the lube oil at that
!particular part load.
  QLubeOilRec = ElecPowerGenerated * CurveValue(CTGenerator(GeneratorNum)%QLubeOilRecoveredCurve, PLR)


!Check for divide by zero
  IF ((HeatRecMdot .GT. 0.0d0) .AND. (HeatRecCp .GT. 0.0d0)) THEN
    HeatRecOutTemp = (QExhaustRec + QLubeOilRec)/(HeatRecMdot * HeatRecCp) + HeatRecInTemp
  ELSE
    HeatRecMdot = 0.0d0
    HeatRecOutTemp = HeatRecInTemp
    QExhaustRec =0.0d0
    QLubeOilRec =0.0d0
  END IF


  !Now verify the maximum temperature was not exceeded
  HRecRatio = 1.0d0
  MinHeatRecMdot=0.0d0
  IF(HeatRecOutTemp > CTGenerator(GeneratorNum)%HeatRecMaxTemp) THEN
   IF(CTGenerator(GeneratorNum)%HeatRecMaxTemp /= HeatRecInTemp)THEN
      MinHeatRecMdot = (QExhaustRec + QLubeOilRec)/(HeatRecCp * (CTGenerator(GeneratorNum)%HeatRecMaxTemp - HeatRecInTemp))
      If(MinHeatRecMdot < 0.0d0) MinHeatRecMdot = 0.0d0
   END IF

    !Recalculate Outlet Temperature, with adjusted flowrate
    IF ((MinHeatRecMdot .GT. 0.0d0) .AND. (HeatRecCp .GT. 0.0d0)) THEN
      HeatRecOutTemp = (QExhaustRec + QLubeOilRec)/(MinHeatRecMdot * HeatRecCp) + HeatRecInTemp
      HRecRatio = HeatRecMdot/MinHeatRecMdot
    ELSE
      HeatRecOutTemp = HeatRecInTemp
      HRecRatio = 0.0d0
    END IF
    QLubeOilRec = QLubeOilRec*HRecRatio
    QExhaustRec = QExhaustRec*HRecRatio
  END IF


        !Calculate Energy
  ElectricEnergyGen    = ElecPowerGenerated*TimeStepSys*SecInHour
  FuelEnergyUsed       = FuelUseRate*TimeStepSys*SecInHour
  LubeOilEnergyRec     = QLubeOilRec*TimeStepSys*SecInHour
  ExhaustEnergyRec     = QExhaustRec*TimeStepSys*SecInHour


  CTGenerator(GeneratorNum)%ElecPowerGenerated = ElecPowerGenerated
  CTGenerator(GeneratorNum)%ElecEnergyGenerated = ElectricEnergyGen

  CTGenerator(GeneratorNum)%HeatRecInletTemp = HeatRecInTemp
  CTGenerator(GeneratorNum)%HeatRecOutletTemp = HeatRecOutTemp

  CTGenerator(GeneratorNum)%HeatRecMdot         = HeatRecMdot
  CTGenerator(GeneratorNum)%QExhaustRecovered   = QExhaustRec
  CTGenerator(GeneratorNum)%QLubeOilRecovered   = QLubeOilRec
  CTGenerator(GeneratorNum)%QTotalHeatRecovered = QExhaustRec + QLubeOilRec
  CTGenerator(GeneratorNum)%FuelEnergyUseRate   = ABS(FuelUseRate)
  CTGenerator(GeneratorNum)%ExhaustEnergyRec    = ExhaustEnergyRec
  CTGenerator(GeneratorNum)%LubeOilEnergyRec    = LubeOilEnergyRec
  CTGenerator(GeneratorNum)%TotalHeatEnergyRec  = ExhaustEnergyRec + LubeOilEnergyRec
  CTGenerator(GeneratorNum)%FuelEnergy          = ABS(FuelEnergyUsed)

  FuelHeatingValue = CTGenerator(GeneratorNum)%FuelHeatingValue

  CTGenerator(GeneratorNum)%FuelMdot =  ABS(FuelUseRate)/(FuelHeatingValue  * KJtoJ)

  CTGenerator(GeneratorNum)%ExhaustStackTemp = ExhaustStackTemp

  RETURN
END SUBROUTINE CalcCTGeneratorModel
All Procedures

CalcCTGeneratorModel Subroutine

Source Code

All Procedures

private subroutine CalcCTGeneratorModel(GeneratorNum, RunFlag, MyLoad, FirstHVACIteration)

Uses:

Arguments

Calls

Called By

Source Code

Source Code

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