FUNCTION PsyTsatFnHPb(H,PB,calledfrom) RESULT(T)
! FUNCTION INFORMATION:
! AUTHOR George Shih
! DATE WRITTEN May 1976
! MODIFIED July 2003; LKL -- peg min/max values (outside range of functions)
! RE-ENGINEERED na
! PURPOSE OF THIS FUNCTION:
! This function provides the saturation temperature from the enthalpy
! and barometric pressure.
! METHODOLOGY EMPLOYED:
! na
! REFERENCES:
! ASHRAE HANDBOOK OF FUNDAMENTALS, 1972, P99, EQN 22
! USE STATEMENTS:
USE psychrolib, ONLY: GetSatAirEnthalpy
IMPLICIT NONE ! Enforce explicit typing of all variables in this routine
! FUNCTION ARGUMENT DEFINITIONS:
REAL(r64), intent(in) :: H ! enthalpy {J/kg}
REAL(r64), intent(in) :: PB ! barometric pressure {Pascals}
character(len=*), intent(in), optional :: calledfrom ! routine this function was called from (error messages)
REAL(r64) :: T ! result=> saturation temperature {C}
! FUNCTION PARAMETER DEFINITIONS:
! na
! INTERFACE BLOCK SPECIFICATIONS
! na
! DERIVED TYPE DEFINITIONS
! na
! FUNCTION LOCAL VARIABLE DECLARATIONS:
REAL(r64) T1 ! APPROXIMATE SATURATION TEMPERATURE (C)
REAL(r64) T2 ! APPROXIMATE SATURATION TEMPERATURE (C)
REAL(r64) TN ! NEW ASSUMED SATURATION TEMPERATURE (C)
REAL(r64) H1 ! APPROXIMATE ENTHALPY (J/KG)
REAL(r64) H2 ! APPROXIMATE ENTHALPY (J/KG)
REAL(r64) Y1 ! ERROR IN ENTHALPY
REAL(r64) Y2 ! ERROR IN ENTHALPY
INTEGER IterCount
REAL(r64) HH ! temporary enthalpy (calculation) value
LOGICAL FlagError ! Set when errors should be flagged
REAL(r64) :: Hloc ! local value of H
! CHECK H IN RANGE.
HH = H + 1.78637d4
IF (H >= 0.0d0) THEN
Hloc = MAX(0.00001d0,H)
ELSE IF (H < 0.0d0) THEN
Hloc = MIN(-.00001d0,H)
END IF
FlagError=.false.
!
IF (HH > 7.5222d4) GO TO 20
IF (HH > 2.7297d4) GO TO 60
IF (HH > -6.7012d2) GO TO 50
IF (HH > -2.2138d4) GO TO 40
IF (HH < -4.24d4) HH=-4.24d4 ! Peg to minimum
GO TO 30
20 CONTINUE
IF (HH < 1.8379d5) GO TO 70
IF (HH < 4.7577d5) GO TO 80
IF (HH < 1.5445d6) GO TO 90
IF (HH < 3.8353d6) GO TO 100
IF (HH > 4.5866d7) HH=4.5866d7 ! Peg to maximum
GO TO 110
!
! TEMP. IS FROM -60 C TO -40 C
30 CONTINUE
T=F6(HH,-19.44d0,8.53675d-4,-5.12637d-9,-9.85546d-14,-1.00102d-18,-4.2705d-24)
GO TO 120
! TEMP. IS FROM -40 C TO -20 C
40 CONTINUE
T=F6(HH,-1.94224d1,8.5892d-4,-4.50709d-9,-6.19492d-14,8.71734d-20,8.73051d-24)
GO TO 120
! TEMP. IS FROM -20 C TO 0 C
50 CONTINUE
T=F6(HH,-1.94224d1,8.59061d-4,-4.4875d-9,-5.76696d-14,7.72217d-19,3.97894d-24)
GO TO 120
! TEMP. IS FROM 0 C TO 20 C
60 CONTINUE
T=F6(HH,-2.01147d1,9.04936d-4,-6.83305d-9,2.3261d-14,7.27237d-20,-6.31939d-25)
GO TO 120
! TEMP. IS FROM 20 C TO 40 C
70 CONTINUE
T=F6(HH,-1.82124d1,8.31683d-4,-6.16461d-9,3.06411d-14,-8.60964d-20,1.03003d-25)
GO TO 120
! TEMP. IS FROM 40 C TO 60 C
80 CONTINUE
T=F6(HH,-1.29419d0,3.88538d-4,-1.30237d-9,2.78254d-15,-3.27225d-21,1.60969d-27)
GO TO 120
! TEMP. IS FROM 60 C TO 80 C
90 CONTINUE
T=F6(HH,2.39214d1,1.27519d-4,-1.52089d-10,1.1043d-16,-4.33919d-23,7.05296d-30)
GO TO 120
! TEMP. IS FROM 80 C TO 90 C
100 CONTINUE
T=F6(HH,4.88446d1,3.85534d-5,-1.78805d-11,4.87224d-18,-7.15283d-25,4.36246d-32)
GO TO 120
! TEMP. IS FROM 90 C TO 100C
110 CONTINUE
T=F7(HH,7.60565d11,5.80534d4,-7.36433d-3,5.11531d-10,-1.93619d-17,3.70511d-25, -2.77313d-33)
! IF THE BAROMETRIC PRESSURE IS
! EQUAL TO 1.0133E5 , SATURATION
! TEMP. IS CALCULATED BY ABOVE EQUA
! OTHERWISE TEMP. IS COMPUTED BY
! FOLLOWING ITERATION METHOD
120 CONTINUE
IF (ABS(PB-1.0133d5)/1.0133d5 <= 0.01d0) GO TO 170
IterCount=0
T1=T
H1=GetSatAirEnthalpy(T1,PB)
Y1=H1-Hloc
IF (ABS(Y1/Hloc) <= 0.1d-4) GO TO 140
T2=T1*0.9d0
130 IterCount=IterCount+1
H2=GetSatAirEnthalpy(T2,PB)
Y2=H2-Hloc
IF (ABS(Y2/Hloc) <= 0.1d-4) GO TO 150
IF (Y2 == Y1) GO TO 150
TN=T2-Y2/(Y2-Y1)*(T2-T1)
IF (IterCount > 30) GO TO 160
T1=T2
T2=TN
Y1=Y2
GO TO 130
140 CONTINUE
T=T1
GO TO 170
150 CONTINUE
T=T2
GO TO 170
160 CONTINUE
170 CONTINUE
! result is T
RETURN
CONTAINS
REAL(r64) FUNCTION F6(X,A0,A1,A2,A3,A4,A5)
IMPLICIT NONE
REAL(r64) X
REAL(r64) A0,A1,A2,A3,A4,A5
F6=A0+X*(A1+X*(A2+X*(A3+X*(A4+X*A5))))
RETURN
END FUNCTION F6
REAL(r64) FUNCTION F7(X,A0,A1,A2,A3,A4,A5,A6)
IMPLICIT NONE
REAL(r64) X,A6
REAL(r64) A0,A1,A2,A3,A4,A5
F7=(A0+X*(A1+X*(A2+X*(A3+X*(A4+X*(A5+X*A6))))))/1.0D10
RETURN
END FUNCTION F7
END FUNCTION PsyTsatFnHPb