CoolProp 물성 DB 및 함수 구조

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• CoolProp 물성 DB
  

CoolProp에서는 기본적으로 「PureFluid 122종류」, 「PredefinedMixture 105종류」의 물성 DB를 보유하고 있다.

해당 DB는 다음 링크를 통해 확인 가능하다.

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1. PureFluid

http://www.coolprop.org/fluid_properties/PurePseudoPure.html

2. PredefinedMixture

http://www.coolprop.org/fluid_properties/Mixtures.html

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• CoolProp 함수 구조
  

개요에서 설명하였듯이 CoolProp은 다양한 프로그램에서 연동되어 사용된다.

이번 장에서는 Excel VBA와 Python에서 사용하는 함수 구조를 설명할 것이다.

기본적으로 냉매는 PropsSI, 습공기는 HAPropsSI 함수를 사용하여 상태량을 계산한다.

「PropsSI」의 경우 상태량 계산을 위해 두 가지 상태량을 입력값으로 줘야하며 함수 구조는 다음과 같다.

Property_ref = PropsSI("Parameter", "Par_input_1", input_1_value, "Par_input_2", input_2_value, "Fluid_name")

<표1: 냉매의 Parameter 종류 및 설명>

Parameter	Units	Input/Output	Trivial	Description
DELTA, Delta		IO	False	Reduced density (rho/rhoc)
DMOLAR, Dmolar	mol/m^3	IO	False	Molar density
D, DMASS, Dmass	kg/m^3	IO	False	Mass density
HMOLAR, Hmolar	J/mol	IO	False	Molar specific enthalpy
H, HMASS, Hmass	J/kg	IO	False	Mass specific enthalpy
P	Pa	IO	False	Pressure
Q	mol/mol	IO	False	Mass vapor quality
SMOLAR, Smolar	J/mol/K	IO	False	Molar specific entropy
S, SMASS, Smass	J/kg/K	IO	False	Mass specific entropy
TAU, Tau		IO	False	Reciprocal reduced temperature (Tc/T)
T	K	IO	False	Temperature
UMOLAR, Umolar	J/mol	IO	False	Molar specific internal energy
U, UMASS, Umass	J/kg	IO	False	Mass specific internal energy
ACENTRIC, acentric		O	True	Acentric factor
ALPHA0, alpha0		O	False	Ideal Helmholtz energy
ALPHAR, alphar		O	False	Residual Helmholtz energy
A, SPEED_OF_SOUND, speed_of_sound	m/s	O	False	Speed of sound
BVIRIAL, Bvirial		O	False	Second virial coefficient
CONDUCTIVITY, L, conductivity	W/m/K	O	False	Thermal conductivity
CP0MASS, Cp0mass	J/kg/K	O	False	Ideal gas mass specific constant pressure specific heat
CP0MOLAR, Cp0molar	J/mol/K	O	False	Ideal gas molar specific constant pressure specific heat
CPMOLAR, Cpmolar	J/mol/K	O	False	Molar specific constant pressure specific heat
CVIRIAL, Cvirial		O	False	Third virial coefficient
CVMASS, Cvmass, O	J/kg/K	O	False	Mass specific constant volume specific heat
CVMOLAR, Cvmolar	J/mol/K	O	False	Molar specific constant volume specific heat
C, CPMASS, Cpmass	J/kg/K	O	False	Mass specific constant pressure specific heat
DALPHA0_DDELTA_CONSTTAU, dalpha0_ddelta_consttau		O	False	Derivative of ideal Helmholtz energy with delta
DALPHA0_DTAU_CONSTDELTA, dalpha0_dtau_constdelta		O	False	Derivative of ideal Helmholtz energy with tau
DALPHAR_DDELTA_CONSTTAU, dalphar_ddelta_consttau		O	False	Derivative of residual Helmholtz energy with delta
DALPHAR_DTAU_CONSTDELTA, dalphar_dtau_constdelta		O	False	Derivative of residual Helmholtz energy with tau
DBVIRIAL_DT, dBvirial_dT		O	False	Derivative of second virial coefficient with respect to T
DCVIRIAL_DT, dCvirial_dT		O	False	Derivative of third virial coefficient with respect to T
DIPOLE_MOMENT, dipole_moment	C m	O	True	Dipole moment
FH		O	True	Flammability hazard
FRACTION_MAX, fraction_max		O	True	Fraction (mole, mass, volume) maximum value for incompressible solutions
FRACTION_MIN, fraction_min		O	True	Fraction (mole, mass, volume) minimum value for incompressible solutions
FUNDAMENTAL_DERIVATIVE_OF_GAS_DYNAMICS, fundamental_derivative_of_gas_dynamics		O	False	Fundamental derivative of gas dynamics
GAS_CONSTANT, gas_constant	J/mol/K	O	True	Molar gas constant
GMOLAR_RESIDUAL, Gmolar_residual	J/mol/K	O	False	Residual molar Gibbs energy
GMOLAR, Gmolar	J/mol	O	False	Molar specific Gibbs energy
GWP100		O	True	100-year global warming potential
GWP20		O	True	20-year global warming potential
GWP500		O	True	500-year global warming potential
G, GMASS, Gmass	J/kg	O	False	Mass specific Gibbs energy
HELMHOLTZMASS, Helmholtzmass	J/kg	O	False	Mass specific Helmholtz energy
HELMHOLTZMOLAR, Helmholtzmolar	J/mol	O	False	Molar specific Helmholtz energy
HH		O	True	Health hazard
HMOLAR_RESIDUAL, Hmolar_residual	J/mol/K	O	False	Residual molar enthalpy
ISENTROPIC_EXPANSION_COEFFICIENT, isentropic_expansion_coefficient		O	False	Isentropic expansion coefficient
ISOBARIC_EXPANSION_COEFFICIENT, isobaric_expansion_coefficient	1/K	O	False	Isobaric expansion coefficient
ISOTHERMAL_COMPRESSIBILITY, isothermal_compressibility	1/Pa	O	False	Isothermal compressibility
I, SURFACE_TENSION, surface_tension	N/m	O	False	Surface tension
M, MOLARMASS, MOLAR_MASS, MOLEMASS, molar_mass, molarmass, molemass	kg/mol	O	True	Molar mass
ODP		O	True	Ozone depletion potential
PCRIT, P_CRITICAL, Pcrit, p_critical, pcrit	Pa	O	True	Pressure at the critical point
PHASE, Phase		O	False	Phase index as a float
PH		O	True	Physical hazard
PIP		O	False	Phase identification parameter
PMAX, P_MAX, P_max, pmax	Pa	O	True	Maximum pressure limit
PMIN, P_MIN, P_min, pmin	Pa	O	True	Minimum pressure limit
PRANDTL, Prandtl		O	False	Prandtl number
PTRIPLE, P_TRIPLE, p_triple, ptriple	Pa	O	True	Pressure at the triple point (pure only)
P_REDUCING, p_reducing	Pa	O	True	Pressure at the reducing point
RHOCRIT, RHOMASS_CRITICAL, rhocrit, rhomass_critical	kg/m^3	O	True	Mass density at critical point
RHOMASS_REDUCING, rhomass_reducing	kg/m^3	O	True	Mass density at reducing point
RHOMOLAR_CRITICAL, rhomolar_critical	mol/m^3	O	True	Molar density at critical point
RHOMOLAR_REDUCING, rhomolar_reducing	mol/m^3	O	True	Molar density at reducing point
SMOLAR_RESIDUAL, Smolar_residual	J/mol/K	O	False	Residual molar entropy (sr/R = s(T,rho) - s^0(T,rho))
TCRIT, T_CRITICAL, T_critical, Tcrit	K	O	True	Temperature at the critical point
TMAX, T_MAX, T_max, Tmax	K	O	True	Maximum temperature limit
TMIN, T_MIN, T_min, Tmin	K	O	True	Minimum temperature limit
TTRIPLE, T_TRIPLE, T_triple, Ttriple	K	O	True	Temperature at the triple point
T_FREEZE, T_freeze	K	O	True	Freezing temperature for incompressible solutions
T_REDUCING, T_reducing	K	O	True	Temperature at the reducing point
V, VISCOSITY, viscosity	Pa s	O	False	Viscosity
Z		O	False	Compressibility factor

*출처: http://www.coolprop.org/coolprop/HighLevelAPI.html#propssi-function

「HAPropsSI」의 경우 세 가지 상태량을 입력값으로 줘야하며 함수 구조는 다음과 같다. (절대습도/상대습도 둘 중 하나는 반드시 들어가야 함.)

Property_air = HAPropsSI("Parameter", "Par_input_1", input_1_value, "Par_input_2", input_2_value, "Par_input_3", input_3_value)

<표2: 공기의 Parameter 종류 및 설명>

Parameter	Units	Input/Output	Description
B, Twb, T_wb, WetBulb	K	Input/Output	Wet-Bulb Temperature
C, cp	J/kg dry air/K	Output	Mixture specific heat per unit dry air
Cha, cp_ha	J/kg humid air/K	Output	Mixture specific heat per unit humid air
CV	J/kg dry air/K	Output	Mixture specific heat at constant volume per unit dry air
CVha, cv_ha	J/kg humid air/K	Output	Mixture specific heat at constant volume per unit humid air
D, Tdp, DewPoint, T_dp	K	Input/Output	Dew-Point Temperature
H, Hda, Enthalpy	J/kg dry air	Input/Output	Mixture enthalpy per dry air
Hha	J/kg humid air	Input/Output	Mixture enthalpy per humid air
K, k, Conductivity	W/m/K	Output	Mixture thermal conductivity
M, Visc, mu	Pa-s	Output	Mixture viscosity
psi_w, Y	mol water/mol humid air	Input/Output	Water mole fraction
P	Pa	Input	Pressure
P_w	Pa	Input	Partial pressure of water vapor
R, RH, RelHum		Input/Output	Relative humidity in [0, 1]
S, Sda, Entropy	J/kg dry air/K	Input/Output	Mixture entropy per unit dry air
Sha	J/kg humid air/K	Input/Output	Mixture entropy per unit humid air
T, Tdb, T_db	K	Input/Output	Dry-Bulb Temperature
V, Vda	m 3${}^3$ /kg dry air	Input/Output	Mixture volume per unit dry air
Vha	m 3${}^3$ /kg humid air	Input/Output	Mixture volume per unit humid air
W, Omega, HumRat	kg water/kg dry air	Input/Output	Humidity Ratio
Z		Output	Compressibility factor (Z = $pv/(RT)$)

*출처: http://www.coolprop.org/fluid_properties/HumidAir.html

추가로 「Excel」에서는 냉매의 경우 PhaseSI 로 유체의 상(phase)을 구하거나 Props1SI 로 임계점(critical point)을 계산할 수 있으며,

「Python」에서는 PropsSI 에서 "Phase" 를 입력하여 유체의 상(phase)을 구하거나, "p_critical" 을 입력하여 임계점(critical point)을 계산할 수 있다.

해당 내용은 뒤에서 자세히 다루도록 하자.