SUBROUTINE TYPE77 (TIME,XIN,OUT,T,DTDT,PAR,INFO,ICNTRL,*) C************************************************************************ C* Copyright ASHRAE A Toolkit for Primary HVAC System Energy C* Calculation C*********************************************************************** C* SUBROUTINE: TYPE77 (CCHIFLSI) C* C* LANGUAGE: FORTRAN 77 C* C* PURPOSE: Numerical simulation of a centrifugal C* chiller in steady-state regime. The C* routine mainly calculates the cooling C* capacity and the compressor consumption for C* specified working conditions. C*********************************************************************** C* INPUT VARIABLES C* Ifluid Selection of the refrigerant (-) C* If Ifluid C* =1: Refrigerant 12 C* =2: Refrigerant 134a C* =3: Refrigerant 114 C* =4: Refrigerant 22 C* =5: Refrigerant 502 C* =6: Refrigerant 717 (Ammonia) C* xin(1) (-) C* Mfrwev Water mass flow rate in the evaporator (kg/s) C* xin(2) (kg/hr) C* Mfrwcd Water mass flow rate in the condenser (kg/s) C* xin(3) (kg/hr) C* Choice If Choice (-) C* =1: the supply water temperature is known for both C* evaporator and condenser C* =2: the water temperature is known at the evaporator C* supply and at the condenser exhaust C* =3: the exhaust water temperature is known for both C* evaporator and condenser C* =4: the water temperature is known at the evaporator C* exhaust and at the condenser supply C* xin(4) (-) C* Twev1 This value is equal to the evaporator supply or (K) C* exhaust water temperature according to the value C* of Choice C* xin(5) (øC) C* Twcd1 This value is equal to the condenser supply or (K) C* exhaust water temperature according to the value C* of Choice C* xin(6) (øC) C* PevG Guess of the cooling capacity (W) C* xin(7) (kJ/hr) C* PcdG Guess of the heat rejected in the condenser (W) C* xin(8) (kJ/hr) C* C* OUTPUT VARIABLES C* MfrRef Refrigerant mass flow rate (kg/s) C* out(1) (kg/hr) C* Pev Cooling capacity (W) C* out(2) (kJ/hr) C* Pcomp Power consumed by the compressor (W) C* out(3) (kJ/hr) C* Pcd Heat rejected in the condenser (W) C* out(4) (kJ/hr) C* COP Coefficient of performance (-) C* out(5) (-) C* Twev2 This value is equal to the evaporator exhaust (K) C* or supply water temperature according to the value C* of Choice C* out(6) (øC) C* Twcd2 This value is equal to the condenser exhaust (K) C* or supply water temperature according to the value C* of Choice C* out(7) (øC) C* ErrDetec This variable is equal to 1 if the routine does (-) C* not converge C* out(8) (-) C* C* PARAMETERS C* AUev Evaporator heat transfer coefficient (W/K) C* par(1) (kJ/hr/øC) C* AUcd Condenser heat transfer coefficient (W/K) C* par(2) (kJ/hr/øC) C* Losses Constant part of the electromechanical losses (W) C* par(3) (kJ/hr) C* Alpha Loss factor allowing to define another (-) C* electromechanical loss which is assumed to be C* proportional to the internal power C* par(4) (-) C* U Peripheral speed of the impeller (m/s) C* par(5) (m/s) C* A Impeller exhaust area (m**2) C* par(6) (m**2) C* Beta Angle between the direction of the vanes at the (-) C* impeller exhaust and the plan tangent to the C* circumference of the impeller (90ø < Beta < 180ø) C* par(7) (-) C* C* WATER PROPERTY C* CpWat Specific heat of liquid water (J/kg/K) C* C* REFRIGERANT PROPERTIES C* To Reference temperature (K) C* cpliq Mean specific heat in saturated liquid state (J/kg/K) C* hfo Enthalpy of the saturated liquid at the (J/kg) C* reference temperature C* cpvap Mean specific heat at constant pressure (J/kg/K) C* in superheated vapor state for saturation C* temperatures ranging from 253 K to 283 K C* cpvapcd Mean specific heat at constant pressure (J/kg/K) C* in superheated vapor state for saturation C* temperatures ranging from 303 K to 333 K C* hfgb Vaporization enthalpy at standard boiling (J/kg) C* point (101325 Pa) C* Tb Standard boiling temperature (K) C* Tc Critical temperature (K) C* b Coefficient used in the calculation of the (-) C* vaporization enthalpy C* r Gas constant (J/kg/K) C* Zeta Mean compressibility factor for saturation (-) C* temperatures ranging from 253 K to 283 K C* Zetacd Mean compressibility factor for saturation (-) C* temperatures ranging from 303 K to 333 K C* Gamma Mean isentropic coefficient (-) C* Acl First coefficient in the Clausius-Clapeyron (-) C* equation C* Bcl Second coefficient in the Clausius-Clapeyron (K) C* equation C*********************************************************************** C MAJOR RESTRICTIONS: The surrounding heat exchanges are C neglected. The refrigerant leaves the C evaporator and the condenser as saturated C vapor and saturated liquid respectively. C The impeller and the diffuser are assumed C to be isentropic. C Perfect gas properties are used. C C DEVELOPER: Jean Lebrun C Jean-Pascal Bourdouxhe C Marc Grodent C University of LiŠge, Belgium C C DATE: March 1, 1995 C C SUBROUTINE CALLED: PROPERTY C LINKCK C*********************************************************************** C INTERNAL VARIABLES: C Twsuev Evaporator supply water temperature (K) C Twexev Evaporator exhaust water temperature (K) C Twsucd Condenser supply water temperature (K) C Twexcd Condenser exhaust water temperature (K) C T1 Evaporating temperature (K) C T1p Temperature after the heating-up (K) C v1p Specific volume after the heating-up (m**3/kg) C p1 Evaporating pressure (Pa) C dhfg Vaporization enthalpy (J/kg) C h1 Enthalpy at the evaporator exhaust (J/kg) C T3 Condensing temperature (K) C h3 Enthalpy at the condenser exhaust (J/kg) C p2 Condensing pressure (Pa) C Win Internal compression power (W) C Effev Evaporator effectiveness (-) C Effcd Condenser effectiveness (-) C pratio Ratio of the condensing pressure to the (-) C evaporating pressure C V Refrigerant volume flow rate at the impeller (m**3/s) C exhaust C pratioi Ratio of the pressure at the impeller exhaust (-) C to the evaporating pressure C Iter1,Iter2 Loop counters (-) C TolRel Relative error tolerance (-) C ErrRel Relative error (-) C IterMax Iteration maximum (-) C C Pevp,Pcdp and T1pp are variables used in the iterative scheme C*********************************************************************** INTEGER*4 INFO DOUBLE PRECISION XIN,OUT REAL Mfrwev,Mfrwcd,MfrRef,Ifluid,Losses DIMENSION PAR(7),XIN(8),OUT(8),INFO(15) COMMON /LUNITS/ LUR,LUW,IFORM,LUK COMMON /SIM/ TIME0,TFINAL,DELT,IWARN COMMON /STORE/ NSTORE,IAV,S(5000) COMMON /CONFIG/ TRNEDT,PERCOM,HEADER,PRTLAB,LNKCHK,PRUNIT,IOCHEK, & PRWARN INFO(6)=8 DATA TolRel,IterMax,CpWat/1E-05,200,4187/ C*** INPUTS 8 (converted in SI units) C************ Ifluid=SNGL(xin(1)) Mfrwev=SNGL(xin(2)/3600.) Mfrwcd=SNGL(xin(3)/3600.) Choice=SNGL(xin(4)) Twev1=SNGL(xin(5)+273.15) Twcd1=SNGL(xin(6)+273.15) PevG=SNGL(xin(7)/3.6) PcdG=SNGL(xin(8)/3.6) C*** PARAMETERS 7 (converted in SI units) C**************** AUev=par(1)/3.6 AUcd=par(2)/3.6 Losses=par(3)/3.6 Alpha=par(4) U=par(5) A=par(6) Beta=par(7) C2*** Selection of the refrigerant CALL PROPERTY (Ifluid,To,cpliq,hfo,cpvap,cpvapcd,hfgb,Tb,Tc, & b,r,Zeta,Zetacd,Gamma,Acl,Bcl,*1) CALL LINKCK('TYPE77','PROPERTY',1,99) 1 CONTINUE Pev=PevG Pcd=PcdG Gm1G=(Gamma-1)/Gamma ErrDetec=0 NChoice=INT(Choice) GOTO (10,20,30,40),NChoice C2*** The supply water temperature is known for both evaporator C2*** and condenser 10 Twsuev=Twev1 Twsucd=Twcd1 GOTO 50 C2*** The water temperature is known at the evaporator supply and C2*** at the condenser exhaust 20 Twsuev=Twev1 Twexcd=Twcd1 GOTO 50 C2*** The exhaust water temperature is known for both C2*** evaporator and condenser 30 Twexev=Twev1 Twexcd=Twcd1 GOTO 50 C2*** The water temperature is known at the evaporator exhaust and C2*** at the condenser supply 40 Twexev=Twev1 Twsucd=Twcd1 50 CONTINUE C1*** Calculate the evaporator and condenser effectivenesses Effev=1-EXP(-AUev/(CpWat*Mfrwev)) Effcd=1-EXP(-AUcd/(CpWat*Mfrwcd)) C1*** Beginning of the first loop Iter1=0 60 Iter1=Iter1+1 C1*** Calculate the evaporating temperature according to the C1*** information available IF ((NChoice.EQ.1).OR.(NChoice.EQ.2)) THEN T1=Twsuev-Pev/(Effev*CpWat*Mfrwev) ELSE T1=Twexev+(Pev/(CpWat*Mfrwev))*(1-1/Effev) ENDIF C1*** Calculate the evaporating pressure p1=1000*EXP(Acl+Bcl/T1) C1*** Calculate the enthalpy at the evaporator exhaust dhfg=hfgb*((Tc-T1)/(Tc-Tb))**b h1=hfo+cpliq*(T1-To)+dhfg C1*** Beginning of the second loop Iter2=0 70 Iter2=Iter2+1 C1*** Calculate the condensing temperature according to the information C1*** available IF ((NChoice.EQ.1).OR.(NChoice.EQ.4)) THEN T3=Twsucd+Pcd/(Effcd*CpWat*Mfrwcd) ELSE T3=Twexcd+(Pcd/(CpWat*Mfrwcd))*(1/Effcd-1) ENDIF C1*** Calculate the condensing pressure p2=1000*EXP(Acl+Bcl/T3) C2*** Calculate the enthalpy at the condenser exhaust h3=hfo+cpliq*(T3-To) C1*** Calculate the system pressure ratio pratio=p2/p1 C1*** Beginning of the third loop C2*** First guess of the temperature after the heating-up T1p=T1 80 CONTINUE C2*** Calculate the specific volume after the heating-up v1p=Zeta*r*T1p/p1 C1*** Calculate the refrigerant volume flow rate at the impeller C1*** exhaust V=A/U*TAN(Beta)*(Zeta*r*T1p*(pratio**Gm1G-1)/Gm1G-U & **2) C2*** Test over the value of the argument of the impeller C2*** pressure ratio Test=1+Gm1G/(2*Zeta*r*T1p)*(U**2-(V/(A*SIN(Beta)))**2) IF (Test.LE.0) THEN ErrDetec=1 GOTO 200 ENDIF C1*** Calculate the impeller pressure ratio pratioi=(1+Gm1G/(2*Zeta*r*T1p)*(U**2-(V/(A*SIN(Beta)))**2 & ))**(1/Gm1G) C1*** Calculate the refrigerant mass flow rate MfrRef=V*pratioi**(1/Gamma)/v1p C2*** Calculate the internal compression power Win=MfrRef*Zeta*r*T1p*(pratio**Gm1G-1)/Gm1G T1pp=T1p C1*** Recalculate the temperature after the heating-up T1p=T1+(Losses+Alpha*Win)/(MfrRef*cpvap) ErrRel=ABS((T1p-T1pp)/T1pp) C2*** If converged, leave the third loop IF (ErrRel.GT.TolRel) GOTO 80 C1*** Calculate the power consumed by the compressor Pcomp=Losses+Alpha*Win+Win Pcdp=Pcd C1*** Calculate the heat rejected in the condenser Pcd=Pev+Pcomp ErrRel=ABS((Pcd-Pcdp)/Pcdp) C2*** If converged, leave the second loop IF ((ErrRel.GT.TolRel).AND.(Iter2.LE.IterMax)) GO TO 70 C1*** Calculate the cooling capacity Pcd=Pcdp Pevp=Pev Pev=MfrRef*(h1-h3) ErrRel=ABS((Pev-Pevp)/Pevp) C2*** If converged, leave the first loop IF ((ErrRel.GT.TolRel).AND.(Iter1.LE.IterMax)) GO TO 60 Pev=Pevp C1*** Calculate the coefficient of performance COP=Pev/Pcomp GOTO (90,100,110,120),NChoice C1*** Calculate the evaporator and condenser exhaust water temperatures 90 Twev2=Twsuev-Pev/(CpWat*Mfrwev) Twcd2=Twsucd+Pcd/(CpWat*Mfrwcd) GOTO 130 C1*** Calculate the evaporator exhaust water temperature and the condenser C1*** supply water temperature 100 Twev2=Twsuev-Pev/(CpWat*Mfrwev) Twcd2=Twexcd-Pcd/(CpWat*Mfrwcd) GOTO 130 C1*** Calculate the evaporator and condenser supply water temperatures 110 Twev2=Twexev+Pev/(CpWat*Mfrwev) Twcd2=Twexcd-Pcd/(CpWat*Mfrwcd) GOTO 130 C1*** Calculate the evaporator supply water temperature and the condenser C1*** exhaust water temperature 120 Twev2=Twexev+Pev/(CpWat*Mfrwev) Twcd2=Twsucd+Pcd/(CpWat*Mfrwcd) 130 CONTINUE 200 CONTINUE C*** OUTPUTS 8 (converted in TRNSYS units) C************* out(1)=DBLE(MfrRef*3600.) out(2)=DBLE(Pev*3.6) out(3)=DBLE(Pcomp*3.6) out(4)=DBLE(Pcd*3.6) out(5)=DBLE(COP) out(6)=DBLE(Twev2-273.15) out(7)=DBLE(Twcd2-273.15) out(8)=DBLE(ErrDetec) RETURN 1 END