CalcTotCapSHR_VSWSHP Subroutine

private subroutine CalcTotCapSHR_VSWSHP(InletDryBulb, InletHumRat, InletEnthalpy, InletWetBulb, AirMassFlowRatio, WaterMassFlowRatio, AirMassFlow, CBF, TotCapNom1, CCapFTemp1, CCapAirFFlow1, CCapWaterFFlow1, TotCapNom2, CCapFTemp2, CCapAirFFlow2, CCapWaterFFlow2, TotCap1, TotCap2, TotCapSpeed, SHR, CondInletTemp, Pressure, SpeedRatio, NumSpeeds)

Uses:
CurveManager

Arguments

Type	Intent		Name
real(kind=r64),	intent(in)	::	InletDryBulb
real(kind=r64),	intent(in)	::	InletHumRat
real(kind=r64),	intent(in)	::	InletEnthalpy
real(kind=r64),	intent(in)	::	InletWetBulb
real(kind=r64),	intent(in)	::	AirMassFlowRatio
real(kind=r64),	intent(in)	::	WaterMassFlowRatio
real(kind=r64),	intent(in)	::	AirMassFlow
real(kind=r64),	intent(in)	::	CBF
real(kind=r64),	intent(in)	::	TotCapNom1
integer,	intent(in)	::	CCapFTemp1
integer,	intent(in)	::	CCapAirFFlow1
integer,	intent(in)	::	CCapWaterFFlow1
real(kind=r64),	intent(in)	::	TotCapNom2
integer,	intent(in)	::	CCapFTemp2
integer,	intent(in)	::	CCapAirFFlow2
integer,	intent(in)	::	CCapWaterFFlow2
real(kind=r64),	intent(out)	::	TotCap1
real(kind=r64),	intent(out)	::	TotCap2
real(kind=r64),	intent(out)	::	TotCapSpeed
real(kind=r64),	intent(out)	::	SHR
real(kind=r64),	intent(in)	::	CondInletTemp
real(kind=r64),	intent(in)	::	Pressure
real(kind=r64),	intent(in)	::	SpeedRatio
integer,	intent(in)	::	NumSpeeds

Source Code

SUBROUTINE CalcTotCapSHR_VSWSHP(InletDryBulb,InletHumRat,InletEnthalpy,InletWetBulb,AirMassFlowRatio, WaterMassFlowRatio, &
                         AirMassFlow,CBF, TotCapNom1,CCapFTemp1,CCapAirFFlow1, CCapWaterFFlow1,&
                          TotCapNom2,CCapFTemp2,CCapAirFFlow2, CCapWaterFFlow2,&
                         TotCap1, TotCap2, TotCapSpeed,SHR,CondInletTemp, Pressure, SpeedRatio, NumSpeeds)

          ! SUBROUTINE INFORMATION:
          !       AUTHOR         Bo Shen, , based on DX:CalcTotCapSHR, introducing two speed levels
          !       DATE WRITTEN   March 2012
          !       MODIFIED       na
          !       RE-ENGINEERED  na

          ! PURPOSE OF THIS SUBROUTINE:
          ! Calculates total capacity and sensible heat ratio of a DX coil at the specified conditions

          ! METHODOLOGY EMPLOYED:
          ! With the rated performance data entered by the user, the model employs some of the
          ! DOE-2.1E curve fits to adjust the capacity and SHR of the unit as a function
          ! of entering air temperatures and supply air flow rate (actual vs rated flow). The model
          ! does NOT employ the exact same methodology to calculate performance as DOE-2, although
          ! some of the DOE-2 curve fits are employed by this model.

          ! The model checks for coil dryout conditions, and adjusts the calculated performance
          ! appropriately.

          ! REFERENCES:
          ! ASHRAE HVAC 2 Toolkit page 4-81.
          !
          ! Henderson, H.I. Jr., K. Rengarajan and D.B. Shirey, III. 1992.The impact of comfort
          ! control on air conditioner energy use in humid climates. ASHRAE Transactions 98(2):
          ! 104-113.
          !
          ! Henderson, H.I. Jr., Danny Parker and Y.J. Huang. 2000.Improving DOE-2's RESYS routine:
          ! User Defined Functions to Provide More Accurate Part Load Energy Use and Humidity
          ! Predictions. Proceedings of ACEEE Conference.


          ! USE STATEMENTS:
  USE CurveManager, ONLY: CurveValue

  IMPLICIT NONE    ! Enforce explicit typing of all variables in this routine

          ! SUBROUTINE ARGUMENT DEFINITIONS:
  REAL(r64), INTENT (IN) :: InletDryBulb       ! inlet air dry bulb temperature [C]
  REAL(r64), INTENT (IN) :: InletHumRat        ! inlet air humidity ratio [kg water / kg dry air]
  REAL(r64), INTENT (IN) :: InletEnthalpy      ! inlet air specific enthalpy [J/kg]
  REAL(r64), INTENT (IN) :: InletWetBulb       ! inlet air wet bulb temperature [C]
  REAL(r64), INTENT (IN) :: AirMassFlowRatio   ! Ratio of actual air mass flow to nominal air mass flow
  REAL(r64), INTENT (IN) :: WaterMassFlowRatio   ! Ratio of actual water mass flow to nominal water mass flow
  REAL(r64), INTENT (IN) :: AirMassFlow        ! actual mass flow for capacity and SHR calculation
  REAL(r64), INTENT (IN) :: CBF                ! coil bypass factor
  INTEGER, INTENT (IN) :: NumSpeeds            ! number of speeds for input

  REAL(r64), INTENT (IN) :: TotCapNom1         ! nominal total capacity at low speed [W]
  INTEGER, INTENT (IN) :: CCapFTemp1           ! capacity modifier curve index, function of entering wetbulb at low speed
  INTEGER, INTENT (IN) :: CCapAirFFlow1        ! capacity modifier curve, function of actual air flow vs rated flow at low speed
  INTEGER, INTENT (IN) :: CCapWaterFFlow1      ! capacity modifier curve, function of actual water flow vs rated flow at low speed

  REAL(r64), INTENT (IN) :: TotCapNom2         ! nominal total capacity at high speed [W]
  INTEGER, INTENT (IN) :: CCapFTemp2           ! capacity modifier curve index, function of entering wetbulb at high speed
  INTEGER, INTENT (IN) :: CCapAirFFlow2        ! capacity modifier curve, function of actual air flow vs rated flow at high speed
  INTEGER, INTENT (IN) :: CCapWaterFFlow2      ! capacity modifier curve, function of actual water flow vs rated flow at high speed


  REAL(r64), INTENT (OUT)   :: TotCap1           ! total capacity at the given conditions [W] at low speed
  REAL(r64), INTENT (OUT)   :: TotCap2           ! total capacity at the given conditions [W] at high speed
  REAL(r64), INTENT (OUT)   :: TotCapSpeed       ! integrated total capacity corresponding to the speed ratio

  REAL(r64), INTENT (OUT)   :: SHR               ! sensible heat ratio at the given conditions
  REAL(r64), INTENT (IN) :: CondInletTemp      ! Condenser inlet temperature [C]
  REAL(r64), INTENT (IN) :: Pressure           ! air pressure [Pa]
  REAL(r64), INTENT (IN) :: SpeedRatio         ! from 0.0 to 1.0


          ! SUBROUTINE PARAMETER DEFINITIONS:
  CHARACTER(len=*), PARAMETER :: RoutineName='CalcTotCapSHR_VSWSHP'

          ! INTERFACE BLOCK SPECIFICATIONS
          ! na

          ! DERIVED TYPE DEFINITIONS
          ! na

          ! SUBROUTINE LOCAL VARIABLE DECLARATIONS:
  REAL(r64) :: InletWetBulbCalc    ! calculated inlet wetbulb temperature used for finding dry coil point [C]
  REAL(r64) :: InletHumRatCalc     ! calculated inlet humidity ratio used for finding dry coil point [kg water / kg dry air]
  REAL(r64) :: TotCapTempModFac1
  ! Total capacity modifier (function of entering wetbulb, outside water inlet temp) at low speed
  REAL(r64) :: TotCapAirFlowModFac1
  ! Total capacity modifier (function of actual supply air flow vs nominal flow) at low speed
  REAL(r64) :: TotCapWaterFlowModFac1
  ! Total capacity modifier (function of actual supply water flow vs nominal flow) at low speed
  REAL(r64) :: TotCapTempModFac2
  ! Total capacity modifier (function of entering wetbulb, outside water inlet temp) at high speed
  REAL(r64) :: TotCapAirFlowModFac2
  ! Total capacity modifier (function of actual supply air flow vs nominal flow) at high speed
  REAL(r64) :: TotCapWaterFlowModFac2
  ! Total capacity modifier (function of actual supply water flow vs nominal flow) at high speed
  REAL(r64) :: hDelta              ! Change in air enthalpy across the cooling coil [J/kg]
  REAL(r64) :: hADP                ! Apparatus dew point enthalpy [J/kg]
  REAL(r64) :: tADP                ! Apparatus dew point temperature [C]
  REAL(r64) :: wADP                ! Apparatus dew point humidity ratio [kg/kg]
  REAL(r64) :: hTinwADP            ! Enthalpy at inlet dry-bulb and wADP [J/kg]
  REAL(r64) :: SHRCalc             ! temporary calculated value of SHR
  REAL(r64) :: TotCapCalc          ! temporary calculated value of total capacity [W]
  REAL(r64) :: TotCapCalc1          ! temporary calculated value of total capacity [W] at low speed
  REAL(r64) :: TotCapCalc2          ! temporary calculated value of total capacity [W] at high speed
  INTEGER :: Counter             ! Counter for dry evaporator iterations
  INTEGER :: MaxIter             ! Maximum number of iterations for dry evaporator calculations
  REAL(r64) :: RF                  ! Relaxation factor for dry evaporator iterations
  REAL(r64) :: Tolerance           ! Error tolerance for dry evaporator iterations
  REAL(r64) :: werror              ! Deviation of humidity ratio in dry evaporator iteration loop
  LOGICAL   :: LoopOn = .TRUE.     ! flag to control the loop iteration

  MaxIter = 30
  RF = 0.4d0
  Counter = 0
  Tolerance = 0.01d0
  werror = 0.0d0

  InletWetBulbCalc = InletWetBulb
  InletHumRatCalc = InletHumRat
  LoopOn = .TRUE.

!  DO WHILE (ABS(werror) .gt. Tolerance .OR. Counter == 0)
!   Get capacity modifying factor (function of inlet wetbulb & outside drybulb) for off-rated conditions
  DO WHILE(LoopOn)
    TotCapTempModFac1 = CurveValue(CCapFTemp1,InletWetBulbCalc,CondInletTemp)
!   Get capacity modifying factor (function of mass flow) for off-rated conditions
    TotCapAirFlowModFac1 = CurveValue(CCapAirFFlow1,AirMassFlowRatio)
    !Get capacity modifying factor (function of mass flow) for off-rated conditions
    IF(CCapWaterFFlow1 .EQ. 0 ) THEN
        TotCapWaterFlowModFac1 = 1.0d0
    ELSE
        TotCapWaterFlowModFac1 = CurveValue(CCapWaterFFlow1,WaterMassFlowRatio)
    END IF

!   Get total capacity
    IF( NumSpeeds  < 2 ) THEN !ONLY ONE SPEED
        TotCapCalc = TotCapNom1 * TotCapAirFlowModFac1 * TotCapWaterFlowModFac1 * TotCapTempModFac1
        TotCapCalc1 = TotCapCalc
        TotCapCalc2 = 0.0d0
    ELSE
        TotCapTempModFac2 = CurveValue(CCapFTemp2,InletWetBulbCalc,CondInletTemp)
        TotCapAirFlowModFac2 = CurveValue(CCapAirFFlow2,AirMassFlowRatio)

        IF(CCapWaterFFlow2 .EQ. 0) THEN
            TotCapWaterFlowModFac2 = 1.0d0
        ELSE
            TotCapWaterFlowModFac2 = CurveValue(CCapWaterFFlow2,WaterMassFlowRatio)
        END IF

        TotCapCalc1 = TotCapNom1 * TotCapAirFlowModFac1 * TotCapWaterFlowModFac1 * TotCapTempModFac1
        TotCapCalc2 = TotCapNom2 * TotCapAirFlowModFac2 * TotCapWaterFlowModFac2 * TotCapTempModFac2

        TotCapCalc = TotCapCalc2*SpeedRatio + (1.0d0 - SpeedRatio ) * TotCapCalc1

    END IF

!   Calculate apparatus dew point conditions using TotCap and CBF
    hDelta = TotCapCalc/AirMassFlow
    hADP = InletEnthalpy - hDelta/(1.d0-CBF)
    tADP = PsyTsatFnHPb(hADP,Pressure)
    wADP = PsyWFnTdbH(tADP,hADP)
    hTinwADP = PsyHFnTdbW(InletDryBulb,wADP)
    SHRCalc = MIN((hTinwADP-hADP)/(InletEnthalpy-hADP),1.d0)
!
!   Check for dry evaporator conditions (win < wadp)
!
    IF (wADP .gt. InletHumRatCalc .or. (Counter .ge. 1 .and. Counter .lt. MaxIter)) THEN
      If(InletHumRatCalc == 0.0d0)InletHumRatCalc=0.00001d0
      werror = (InletHumRatCalc - wADP)/InletHumRatCalc
!
!     Increase InletHumRatCalc at constant inlet air temp to find coil dry-out point. Then use the
!     capacity at the dry-out point to determine exiting conditions from coil. This is required
!     since the TotCapTempModFac doesn't work properly with dry-coil conditions.
!
      InletHumRatCalc = RF*wADP + (1.d0-RF)*InletHumRatCalc
      InletWetBulbCalc = PsyTwbFnTdbWPb(InletDryBulb,InletHumRatCalc,Pressure)
      Counter = Counter + 1
      IF (ABS(werror) .gt. Tolerance) THEN
        LoopOn = .TRUE. !go to 50   ! Recalculate with modified inlet conditions
      ELSE
        LoopOn = .FALSE.
      END IF
    ELSE
      LoopOn = .FALSE.
    END IF
  END DO

! END DO

!  Calculate full load output conditions
  IF (SHRCalc .gt. 1.d0 .OR. Counter .gt. 0) SHRCalc = 1.d0

  SHR = SHRCalc
  TotCap1 = TotCapCalc1
  TotCap2 = TotCapCalc2
  TotCapSpeed = TotCapCalc

 ! IF(SHR < 0.3d0) SHR = 0.3d0

  RETURN
END SUBROUTINE CalcTotCapSHR_VSWSHP

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CalcTotCapSHR_VSWSHP Subroutine

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