Introduction of CoolProp for Excel

CoolProp provides functions for thermophysical properties of fluids. It is open-source, free, and licensed under the MIT License. Basically, you can do anything you like with the MIT license. It is very permissive and not copy-left. You can use CoolProp in commercial code.

0.0 General

CoolProp supports lots of programming languages, 122 pure and pseudo-pure fluids, and some mixtures.

Download address:

https://sourceforge.net/projects/coolprop/files/CoolProp/

Detailed document:

http://www.coolprop.org

After installation, we need to activate CoolProp. In Excel, please activate "CoolProp" in Excel Add-ins dialog box. In VBA Editor, please activate "CoolProp" in References dialog box.

For a string literal in Excel or VBA, use double-quotation-marks ( " ) instead of single-quotation-marks ( ' ).

This article is tested per CoolProp Version 6.4.

1.0 High-Level Functions

CoolProp for Excel provides four high-level functions: PropsSI, Props1SI, PhaseSI, HAPropsSI.

1.1 PropsSI

Function PropsSI(ByVal output As String, ByVal Name1 As String, ByVal Value1 As Double, ByVal Name2 As String, ByVal Value2 As Double, ByVal fluid As String)

The parameter output is the name of output property that will be returned. Parameters Name1 and Value1 are the name and value of the first input property. Parameters Name2 and Value2 are the name and value of the second input property. The parameter fluid is the name of fluid for which the output property will be calculated.

Per State Postulate in thermodynamics, the state of a pure substance will be determined when two independent, intensive properties are given. That is why two properties are required as function input.

For the name of properties, please refer to Section 2.1 in this article.

CoolProp only uses SI units for input/output properties, other systems of units are not supported. For the unit of properties, please refer to Section 2.1 in this article.

VBA Example:

Private Sub Test1_1()

'density of Nitrogen at 101325 Pa & 300 K

D1 = PropsSI("D", "P", 101325, "T", 300, "Nitrogen")

Debug.Print D1 & " kg/m^3"     '1.13816468646245 kg/m^3

'order of input properties is irrelevant

D2 = PropsSI("D", "T", 300, "P", 101325, "Nitrogen")

Debug.Print D2 & " kg/m^3"     '1.13816468646245 kg/m^3

End Sub

1.2 Props1SI

Function Props1SI(ByVal fluid As String, ByVal output As String)

Some fluid information (e.g.,  pressure at the critical point) is not related to the state of the fluid, so only fluid name (parameter fluid) and output property name (parameter output) are required.

For the name and unit of parameter output in function Props1SI, please refer to Section 2.2 in this article.

VBA Example:

Private Sub Test1_2()

'call Props1SI function

Tcrit1 = Props1SI(“Tcrit”,”Water”)

Debug.Print Tcrit1 & " K"    '647.096 K

'call PropsSI function using dummy arguments for the unused parameters

Tcrit2 = PropsSI("Tcrit","",0,"",0,"Water")

Debug.Print Tcrit2 & " K"    '647.096 K

End Sub

1.3 PhaseSI 

Function PhaseSI(ByVal Name1 As String, ByVal Value1 As Double, ByVal Name2 As String, ByVal Value2 As Double, ByVal fluid As String)

PhaseSI function only returns the name of the phase, therefore there is no parameter output.

VBA Example:

Private Sub Test1_3()

'PhaseSI function returns name of phase (as string)

phase1 = PhaseSI('P',101325,'Q',0,'Water')

Debug.Print phase1    'twophase

'PropsSI function returns phase index (as floating point number)

phase2 = PropsSI('Phase','P',101325,'Q',0,'Water')

Debug.Print phase2    '6.0

End Sub

1.4 HAPropsSI

Function HAPropsSI(ByVal output As String, ByVal Input1Name As String, ByVal Value1 As Double, ByVal Input2Name As String, ByVal Value2 As Double, ByVal Input3name As String, ByVal Value3 As Double)

HAPropsSI function returns the property of humid air. It requires three properties as function input, and one of them should be humidity. HAPropsSI function is based on ASHREA-RP1485. It is applicable for pressure from 0.01 kPa up to 10 MPa, in a temperature range from -143.15 °C up to 350 °C with a humidity ratio from 0 kg of water up to 10 kg of water per kg of dry air.

For the name and unit of parameters in function HAPropsSI, please refer to Section 2.3 in this article.

VBA Example:

Private Sub Test1_4()

'Enthalpy at dry bulb temperature T of 25C, 

'pressure P of one atmosphere, relative humidity R of 50%

h = HAPropsSI('H','T',298.15,'P',101325,'R',0.5)

Debug.Print h & " J per kg dry air"    '50423.45039076901

#Temperature of saturated air

T1 = HAPropsSI('T','P',101325,'H',h,'R',1.0)

Debug.Print T1 & " K"    '290.96209246907983 K

'order of input properties doesn't matter

T2 = HAPropsSI('T','H',h,'R',1.0,'P',101325)

Debug.Print T2 & " K"    '290.96209246907983 K

End Sub

2.0 Table of String Inputs

2.1 Inputs/Outputs to PropsSI Function

Common properties for PropsSI function are listed in the following table. For a complete list, please refer to:

http://www.coolprop.org/coolprop/HighLevelAPI.html#table-of-string-inputs-to-propssi-function

Parameter	Units	Input/Output	Description
DMOLAR, Dmolar	mol/m^3	IO	Molar density
D, DMASS, Dmass	kg/m^3	IO	Mass density
HMOLAR, Hmolar	J/mol	IO	Molar specific enthalpy
H, HMASS, Hmass	J/kg	IO	Mass specific enthalpy
P	Pa	IO	Pressure
Q	mol/mol	IO	Mass vapor quality
SMOLAR, Smolar	J/mol/K	IO	Molar specific entropy
S, SMASS, Smass	J/kg/K	IO	Mass specific entropy
T	K	IO	Temperature
UMOLAR, Umolar	J/mol	IO	Molar specific internal energy
U, UMASS, Umass	J/kg	IO	Mass specific internal energy
CONDUCTIVITY, L, conductivity	W/m/K	O	Thermal conductivity
CP0MASS, Cp0mass	J/kg/K	O	Ideal gas mass specific constant pressure specific heat
CP0MOLAR, Cp0molar	J/mol/K	O	Ideal gas molar specific constant pressure specific heat
CPMOLAR, Cpmolar	J/mol/K	O	Molar specific constant pressure specific heat
CVMASS, Cvmass, O	J/kg/K	O	Mass specific constant volume specific heat
CVMOLAR, Cvmolar	J/mol/K	O	Molar specific constant volume specific heat
C, CPMASS, Cpmass	J/kg/K	O	Mass specific constant pressure specific heat
PHASE, Phase		O	Phase index as a float
PRANDTL, Prandtl		O	Prandtl number
V, VISCOSITY, viscosity	Pa s	O	Viscosity
Z		O	Compressibility factor

In Input/Output column, I indicates properties for parameters Name1, Name2; O indicates properties for parameters output.

2.2 Trivial Inputs for Props1SI Function

Common properties for Props1SI function are listed in the following table. For a complete list, please refer to:

http://www.coolprop.org/coolprop/HighLevelAPI.html#trivial-inputs

Parameter	Units	Description
GAS_CONSTANT, gas_constant	J/mol/K	Molar gas constant
M, MOLARMASS, MOLAR_MASS, molar_mass, molarmass	kg/mol	Molar mass
PCRIT, P_CRITICAL, Pcrit, p_critical, pcrit	Pa	Pressure at the critical point
RHOCRIT, RHOMASS_CRITICAL, rhocrit, rhomass_critical	kg/m^3	Mass density at critical point
RHOMOLAR_CRITICAL, rhomolar_critical	mol/m^3	Molar density at critical point
TCRIT, T_CRITICAL, T_critical, Tcrit	K	Temperature at the critical point
PTRIPLE, P_TRIPLE, p_triple, ptriple	Pa	Pressure at the triple point (pure only)
TTRIPLE, T_TRIPLE, T_triple, Ttriple	K	Temperature at the triple point
FRACTION_MAX, fraction_max		Fraction (mole, mass, volume) maximum value for incompressible solutions
FRACTION_MIN, fraction_min		Fraction (mole, mass, volume) minimum value for incompressible solutions
T_FREEZE, T_freeze	K	Freezing temperature for incompressible solutions
PMAX, P_MAX, P_max, pmax	Pa	Maximum pressure limit
PMIN, P_MIN, P_min, pmin	Pa	Minimum pressure limit
TMAX, T_MAX, T_max, Tmax	K	Maximum temperature limit
TMIN, T_MIN, T_min, Tmin	K	Minimum temperature limit

2.3 Inputs/Outputs to HAPropsSI Function

Complete properties for HAPropsSI function are listed in the following table:

Parameter	Units	Input/Output	Description
P	Pa	Input	Pressure
P_w	Pa	Input	Partial pressure of water vapor
T, Tdb, T_db	K	Input/Output	Dry-Bulb Temperature
B, Twb, T_wb, WetBulb	K	Input/Output	Wet-Bulb Temperature
D, Tdp, DewPoint, T_dp	K	Input/Output	Dew-Point Temperature
psi_w, Y	mol water/mol humid air	Input/Output	Water mole fraction
R, RH, RelHum		Input/Output	Relative humidity in [0, 1]
W, Omega, HumRat	kg water/kg dry air	Input/Output	Humidity Ratio
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
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
V, Vda	m^3 /kg dry air	Input/Output	Mixture volume per unit dry air
Vha	m^3 /kg humid air	Input/Output	Mixture volume per unit humid air
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
K, k, Conductivity	W/m/K	Output	Mixture thermal conductivity
M, Visc, mu	Pa-s	Output	Mixture viscosity
Z		Output	Compressibility factor Z=pv/(RT)

In Input/Output column, Input indicates properties for parameters Name1,  Name2,  Name3; Output indicates properties for parameters output.

3.0 Fluids

3.1 Pure and Pseudo-Pure Fluids

Common pure and pseudo-pure fluids are listed in the following table. For a complete list, please refer to:

http://www.coolprop.org/fluid_properties/PurePseudoPure.html#list-of-fluids

Name	Thermal Conductivity	Viscosity	Melting Line	Surface Tension
Air	✓	✓
Ammonia	✓	✓		✓
Argon	✓	✓	✓	✓
CarbonDioxide	✓	✓	✓	✓
CarbonMonoxide			✓	✓
Ethane	✓	✓	✓	✓
Ethanol	✓	✓	✓	✓
Hydrogen	✓	✓	✓	✓
IsoButane	✓	✓	✓	✓
Isopentane	✓	✓	✓	✓
Methane	✓	✓	✓	✓
Methanol	✓	✓	✓	✓
Nitrogen	✓	✓	✓	✓
Oxygen	✓	✓	✓	✓
Water	✓	✓	✓	✓
n-Butane	✓	✓	✓	✓
n-Hexane	✓	✓		✓
n-Pentane	✓	✓	✓	✓
n-Propane	✓	✓	✓	✓

For Thermal Conductivity, Viscosity, Melting Line, Surface Tension, not all of these properties are supported for a given fluid.

3.2 IAPWS-IF97

The International Association for the Properties of Water and Steam released IAPWS-IF97 for fast computation of water properties. The IF97 backend can be accessed in function PropsSI and function Props1SI. However, water is the only fluid name that can be specified, as "IF97::Water". The following figure is the valid range of temperature and pressure. Temperature and pressure outside of these regions will result in an “Out of Range” error.

VBA Example:

Private Sub Test3_2()

T_init = 500#

P_init = 101325

S_init = PropsSI("S", "T", T_init, "P", P_init, "IF97::Water")  '7938.58736435735

H_init = PropsSI("H", "S", S_init, "P", P_init, "IF97::Water")  '2928535.50133066

T_final = PropsSI("T", "H", H_init, "P", P_init, "IF97::Water") '499.998052904717

Debug.Print S_init & " J/kg/K"

Debug.Print H_init & " J/kg"

Debug.Print T_final & " K"

End Sub

3.3 Incompressible Fluids

In CoolProp, the incompressible fluids are divided into three major groups.

• Pure fluids
• Mass-based binary mixtures
• Volume-based binary mixtures

The incompressible pure fluids implemented in CoolProp cover secondary refrigerants, heat transfer oils, and molten salt mixture. For a complete list of incompressible pure fluids and temperature range, please refer to:

http://www.coolprop.org/fluid_properties/Incompressibles.html#pure

For mass-based binary mixtures and volume-based binary mixtures. Most of them are secondary heat transfer fluids, but there are also aqueous ammonia (MAM) and lithium bromide (LiBr). The concentration always refers to the added component ranging from 0.0 for pure water to 1.0 for no water at all. For a complete list of mass-based and volume-based binary mixtures, temperature range and concentration range, please refer to:

http://www.coolprop.org/fluid_properties/Incompressibles.html#massmix

http://www.coolprop.org/fluid_properties/Incompressibles.html#volumix

VBA Example:

Private Sub Test3_3()

'Incompressible, Pure fluid

T_init = 500#

P_init = 101325

H_init = PropsSI("H", "T", T_init, "P", P_init, "INCOMP::DowQ") '408385.32146991

Debug.Print H_init & " J/kg"

'Incompressible, Mass-based binary mixture

'The fraction notation can be in the form of percent, LiBr-23%, or as a fraction between 0 and 1, LiBr[0.23]

D1 = PropsSI("D", "T", 300, "P", 101325, "INCOMP::LiBr[0.23]")  '1187.54382436172

D2 = PropsSI("D", "T", 300, "P", 101325, "INCOMP::LiBr-23%")    '1187.54382436172

Debug.Print "D1 = " & D1 & " kg/m^3" & vbNewLine & _

            "D2 = " & D2 & " kg/m^3"

'Incompressible, MITSW  (MIT Seawater)

Dsea = PropsSI("D", "T", 300, "P", 101325, "INCOMP::MITSW-3.5%")    '1022.97856743166

Debug.Print Dsea & " kg/m^3"

End Sub

3.4 Mixture

The only types of inputs that are allowed for mixtures right now are:

• Pressure/quality
• Temperature/quality
• Temperature/pressure

The format of mixture name is:

"Name1[Frac1]&Name2[Frac2]&Name3[Frac3]"

Components are separated by ("&"); the fraction of the component is in ("[") and ("]") brackets; the fraction of mixture adopts mole fractions; space (" ") is not allowed in mixture name.

CoolProp provides MixtureString function for Excel:

Function MixtureString(names As Range, fractions As Range) As String

The parameter names is the Excel cells for component names of the mixture. The parameter fractions is the Excel cells for component fractions of the mixture. A string for mixture name will be returned.

Mixture calculations require binary interaction parameters for each pair in the mixture. While many binary interaction parameters are available in the CoolProp library, sadly, many are not. For a complete list of binary pairs, please refer to:

http://www.coolprop.org/fluid_properties/Mixtures.html#binary-pairs