Python Wrapper

PyFluids (3-party wrapper)

It is a simple, full-featured, lightweight CoolProp wrapper for Python. PyFluids gets published on PyPI, so you can easily install it using:

pip install pyfluids

All CoolProp features are included: thermophysical properties of pure fluids, mixtures and humid air. Also you can easily convert the results to a JSON string or Python dict, add new properties or inputs for lookups, and more.

Benefits

  • Easy to use: all fluids and properties are at hand, no need to remember CoolProp keys.

  • Processes for fluids and humid air are included: there is no need to code it anymore.

  • User-friendly interface: writing code is faster.

Examples

To calculate the specific heat of saturated water vapor at 1 atm:

from pyfluids import Fluid, FluidsList

water_vapour = Fluid(FluidsList.Water).dew_point_at_pressure(101325)
print(water_vapour.specific_heat)  # 2079.937085633241

To calculate the dynamic viscosity of propylene glycol aqueous solution with 60 % mass fraction at 100 kPa and -20 °C:

from pyfluids import Fluid, FluidsList, Input

propylene_glycol = Fluid(FluidsList.MPG, 60).with_state(
    Input.pressure(100e3), Input.temperature(-20)
)
print(propylene_glycol.dynamic_viscosity)  # 0.13907391053938878

To calculate the density of ethanol aqueous solution (with ethanol 40 % mass fraction) at 200 kPa and 4 °C:

from pyfluids import Mixture, FluidsList, Input

mixture = Mixture([FluidsList.Water, FluidsList.Ethanol], [60, 40]).with_state(
    Input.pressure(200e3), Input.temperature(4)
)
print(mixture.density)  # 883.3922771627963

To calculate the wet bulb temperature of humid air at 99 kPa, 30 °C and 50 % relative humidity:

from pyfluids import HumidAir, InputHumidAir

humid_air = HumidAir().with_state(
    InputHumidAir.pressure(99e3),
    InputHumidAir.temperature(30),
    InputHumidAir.relative_humidity(50),
)
print(humid_air.wet_bulb_temperature)  # 21.946578559079228

For any questions or more examples, see PyFluids on GitHub.

Automatic installation

Using the pip installation program, you can install the official release from the pypi server using:

pip install CoolProp

There are also unofficial Conda packages available from the conda-forge channel. To install, use:

conda install conda-forge::coolprop

If you dare, you can also try the latest nightly release from Python or get it directly from the development server using:

pip install -vvv --pre --trusted-host www.coolprop.dreamhosters.com --find-links http://www.coolprop.dreamhosters.com/binaries/Python/ -U --no-cache --force-reinstall CoolProp

Manual installation

Compilation of the python wrapper requires a few common wrapper pre-requisites

On all platforms, if it is not already there, you need Cython to be installed:

sudo pip install Cython

Then, follow the commands:

# Check out the sources for CoolProp
git clone https://github.com/CoolProp/CoolProp --recursive
# Move into the folder you just created
cd CoolProp/wrappers/Python
# Start the installation
sudo python setup.py install

If you would like to install CoolProp just for a given version of Python (for example if python links to python3.4 and you also have a python2.7 executable), simply use this version of python to execute the setup.py script:

sudo python2.7 setup.py install

If you have multiple versions of Visual Studio installed and need to specify the version to use and choice of 32-bit or 64-bit compilation, you can use:

# 64-bit using VS2008 on Pytnon 2.7
sudo python setup.py install --cmake-compiler vc9 --cmake-bitness 64

or, equivalently:

sudo python setup.py install cmake=vc9,64

Omitting the cmake options will use the default (latest) compiler on the machine.

Local installation

If you prefer not to be sudoer when compiling coolprop on Linux/MacOS, you can also install it locally using the --user switch:

# Check out the sources for CoolProp
git clone https://github.com/CoolProp/CoolProp --recursive
# Move into the folder you just created
cd CoolProp/wrappers/Python
# Start the installation
python setup.py install --user

For Pyzo users

Suppose the directory containing pyzo is on your Desktop in ~/Desktop/pyzo2014a/. Then you can install CoolProp to be used within pyzo by following the same lines as above:

# Check out the sources for CoolProp
git clone https://github.com/CoolProp/CoolProp --recursive
# Move into the folder you just created
cd CoolProp/wrappers/Python
# Start the installation (~/Desktop/pyzo2014a/ to be changed according to
# your effective installation)
sudo ~/Desktop/pyzo2014a/bin/python setup.py install

Usage

There is example code at the end of this page

Once installed, you can use CoolProp for various things:

  • Compute special values in SI units:

    import CoolProp.CoolProp as CP
fluid = 'Water'
pressure_at_critical_point = CP.PropsSI(fluid,'pcrit')
# Massic volume (in m^3/kg) is the inverse of density
# (or volumic mass in kg/m^3). Let's compute the massic volume of liquid
# at 1bar (1e5 Pa) of pressure
vL = 1/CP.PropsSI('D','P',1e5,'Q',0,fluid)
# Same for saturated vapor
vG = 1/CP.PropsSI('D','P',1e5,'Q',1,fluid)

  • Get some nice graphs:

    import CoolProp.Plots as CPP
ph_plot = CPP.PropertyPlot('Water','Ph')
ph_plot.savefig('enthalpy_pressure_graph_for_Water.png')

  • Solve thermodynamics exercices

  • Make your own more complex graphs if you feel the graphing interface is lacking something

  • Make even more complex graphs using 3D stuff

Example Code

from __future__ import print_function
from CoolProp import AbstractState
from CoolProp.CoolProp import PhaseSI, PropsSI, get_global_param_string
import CoolProp.CoolProp as CoolProp
from CoolProp.HumidAirProp import HAPropsSI
from math import sin
print("**************** INFORMATION ***************")
print("This example was auto-generated by the language-agnostic dev/scripts/example_generator.py script written by Ian Bell")
print("CoolProp version:", get_global_param_string("version"))
print("CoolProp gitrevision:", get_global_param_string("gitrevision"))
print("CoolProp Fluids:", get_global_param_string("FluidsList"))
# See http://www.coolprop.org/coolprop/HighLevelAPI.html#table-of-string-inputs-to-propssi-function for a list of inputs to high-level interface
print("*********** HIGH LEVEL INTERFACE *****************")
print("Critical temperature of water:", PropsSI("Water", "Tcrit"), "K")
print("Boiling temperature of water at 101325 Pa:", PropsSI("T", "P", 101325, "Q", 0, "Water"), "K")
print("Phase of water at 101325 Pa and 300 K:", PhaseSI("P", 101325, "T", 300, "Water"))
print("c_p of water at 101325 Pa and 300 K:", PropsSI("C", "P", 101325, "T", 300, "Water"), "J/kg/K")
print("c_p of water (using derivatives) at 101325 Pa and 300 K:", PropsSI("d(H)/d(T)|P", "P", 101325, "T", 300, "Water"), "J/kg/K")
print("*********** HUMID AIR PROPERTIES *****************")
print("Humidity ratio of 50% rel. hum. air at 300 K, 101325 Pa:", HAPropsSI("W", "T", 300, "P", 101325, "R", 0.5), "kg_w/kg_da")
print("Relative humidity from last calculation:", HAPropsSI("R", "T", 300, "P", 101325, "W", HAPropsSI("W", "T", 300, "P", 101325, "R", 0.5)), "(fractional)")
print("*********** INCOMPRESSIBLE FLUID AND BRINES *****************")
print("Density of 50% (mass) ethylene glycol/water at 300 K, 101325 Pa:", PropsSI("D", "T", 300, "P", 101325, "INCOMP::MEG-50%"), "kg/m^3")
print("Viscosity of Therminol D12 at 350 K, 101325 Pa:", PropsSI("V", "T", 350, "P", 101325, "INCOMP::TD12"), "Pa-s")
# If you don't have REFPROP installed, disable the following lines
print("*********** REFPROP *****************")
print("REFPROP version:", get_global_param_string("REFPROP_version"))
print("Critical temperature of water:", PropsSI("REFPROP::WATER", "Tcrit"), "K")
print("Boiling temperature of water at 101325 Pa:", PropsSI("T", "P", 101325, "Q", 0, "REFPROP::WATER"), "K")
print("c_p of water at 101325 Pa and 300 K:", PropsSI("C", "P", 101325, "T", 300, "REFPROP::WATER"), "J/kg/K")
print("*********** TABULAR BACKENDS *****************")
TAB = AbstractState("BICUBIC&HEOS", "R245fa")
TAB.update(CoolProp.PT_INPUTS, 101325, 300)
print("Mass density of refrigerant R245fa at 300 K, 101325 Pa:", TAB.rhomass(), "kg/m^3")
print("*********** SATURATION DERIVATIVES (LOW-LEVEL INTERFACE) ***************")
AS_SAT = AbstractState("HEOS", "R245fa")
AS_SAT.update(CoolProp.PQ_INPUTS, 101325, 0)
print("First saturation derivative:", AS_SAT.first_saturation_deriv(CoolProp.iP, CoolProp.iT), "Pa/K")
print("*********** LOW-LEVEL INTERFACE *****************")
AS = AbstractState("HEOS", "Water&Ethanol")
z = [0.5, 0.5]
AS.set_mole_fractions(z)
AS.update(CoolProp.PQ_INPUTS, 101325, 1)
print("Normal boiling point temperature of water and ethanol:", AS.T(), "K")
# If you don't have REFPROP installed, disable the following block
print("*********** LOW-LEVEL INTERFACE (REFPROP) *****************")
AS2 = AbstractState("REFPROP", "METHANE&ETHANE")
z2 = [0.2, 0.8]
AS2.set_mole_fractions(z2)
AS2.update(CoolProp.QT_INPUTS, 1, 120)
print("Vapor molar density:", AS2.keyed_output(CoolProp.iDmolar), "mol/m^3")

Example Code Output

**************** INFORMATION ***************
This example was auto-generated by the language-agnostic dev/scripts/example_generator.py script written by Ian Bell
CoolProp version: 6.6.0
CoolProp gitrevision: ba21c74fd1c3a4934bbecbf459936983dec424c2
CoolProp Fluids: n-Nonane,MethylLinolenate,DimethylCarbonate,R21,DiethylEther,trans-2-Butene,R245fa,ParaDeuterium,OrthoDeuterium,Isohexane,R365MFC,n-Dodecane,R410A,Deuterium,D4,R13,MD2M,n-Hexane,Methane,Ethane,CarbonylSulfide,EthylBenzene,CarbonMonoxide,Isopentane,Xenon,cis-2-Butene,R152A,Oxygen,EthyleneOxide,R1234ze(E),n-Octane,R404A,R236EA,CycloHexane,n-Heptane,R22,R113,n-Pentane,MethylLinoleate,R11,SulfurDioxide,R23,Helium,R32,R227EA,R407C,HydrogenSulfide,Air,R245ca,Novec649,R143a,D5,R507A,R134a,Dichloroethane,ParaHydrogen,R1233zd(E),Acetone,n-Decane,HeavyWater,MethylPalmitate,n-Propane,R115,R1234yf,R236FA,Ethylene,R116,MD4M,Benzene,Methanol,SulfurHexafluoride,o-Xylene,R125,Fluorine,R1234ze(Z),CarbonDioxide,IsoButane,n-Butane,NitrousOxide,DimethylEther,RC318,Toluene,IsoButene,MethylStearate,Ammonia,Argon,R218,R41,Neon,Propyne,CycloPropane,R12,Nitrogen,Water,MethylOleate,R161,D6,SES36,HFE143m,n-Undecane,R123,HydrogenChloride,m-Xylene,R141b,R124,1-Butene,Propylene,R14,p-Xylene,Cyclopentane,MDM,Hydrogen,Neopentane,Ethanol,OrthoHydrogen,R114,Krypton,MD3M,R1243zf,MM,R142b,R40,R13I1
*********** HIGH LEVEL INTERFACE *****************
Critical temperature of water: 647.096 K
Boiling temperature of water at 101325 Pa: 373.1242958476844 K
Phase of water at 101325 Pa and 300 K: liquid
c_p of water at 101325 Pa and 300 K: 4180.6357765560715 J/kg/K
c_p of water (using derivatives) at 101325 Pa and 300 K: 4180.6357765560715 J/kg/K
*********** HUMID AIR PROPERTIES *****************
Humidity ratio of 50% rel. hum. air at 300 K, 101325 Pa: 0.011095529705199761 kg_w/kg_da
Relative humidity from last calculation: 0.5 (fractional)
*********** INCOMPRESSIBLE FLUID AND BRINES *****************
Density of 50% (mass) ethylene glycol/water at 300 K, 101325 Pa: 1061.1793077204613 kg/m^3
Viscosity of Therminol D12 at 350 K, 101325 Pa: 0.0005228837990955358 Pa-s
*********** REFPROP *****************
REFPROP version: 10.0
Critical temperature of water: 647.096 K
Boiling temperature of water at 101325 Pa: 373.124295847701 K
c_p of water at 101325 Pa and 300 K: 4180.635776575593 J/kg/K
*********** TABULAR BACKENDS *****************
Mass density of refrigerant R245fa at 300 K, 101325 Pa: 5.648128257046375 kg/m^3
*********** SATURATION DERIVATIVES (LOW-LEVEL INTERFACE) ***************
First saturation derivative: 4058.5197550507155 Pa/K
*********** LOW-LEVEL INTERFACE *****************
Normal boiling point temperature of water and ethanol: 357.2729801712649 K
*********** LOW-LEVEL INTERFACE (REFPROP) *****************
Vapor molar density: 0.44146562665387795 mol/m^3

Code Warnings

Messages may be issued from the Python CoolProp wrapper via the Python warnings module. This module allows non-fatal warning messages to be issued to the calling program and stdout to warn of improper function usage or deprecation of features. These warnings will, by default, be issued each and every time a suspect call is made to CoolProp. While, the best solution is to correct the calling code according to the message received, sometimes this is difficult to do in a legacy or third party code and can result in many, many warning messages that obscure the output and hinder debugging.

Suppressing warning messages

The calling code can suppress or ignore these warning messages by overriding the default warnings filter and changing the behavior of the warnings module. As an example, the following script will result in a DeprecationWarning on each call to the deprecated function Props():

from CoolProp.CoolProp import Props
Rho = Props('D','T',298.15,'P',10000,'R744')
print("R744 Density at {} K and {} kPa      = {} kg/m³".format(298.15, 10000, Rho))
H = Props('H','T',298.15,'Q',1,'R134a');
print("R134a Saturated Liquid Enthalpy at {} K = {} kJ/kg".format(298.15, H))

Example output:

TestProps.py:14: DeprecationWarning: Props() function is deprecated; Use the PropsSI() function
Rho = Props('D','T',298.15,'P',10000,'R744')
R744 Density at 298.15 K and 10000 kPa      = 817.6273812375758 kg/m³
TestProps.py:16: DeprecationWarning: Props() function is deprecated; Use the PropsSI() function
H = Props('H','T',298.15,'Q',1,'R134a');
R134a Saturated Liquid Enthalpy at 298.15 K = 412.33395323186807 kJ/kg

Legacy applications can create a filter override to ignore all deprecation warnings by including the following code just after the last import from CoolProp, but before any calls to CoolProp:

import warnings
warnings.filterwarnings('ignore', category=DeprecationWarning)

To suppress, for example, only deprecation warning messages that contain the string “Props()”, the second parameter to filterwarnings() can be a pattern matching regular expression:

import warnings
warnings.filterwarnings('ignore', '.*Props()*.', category=DeprecationWarning)

This filter will suppress any DeprecationWarning messages that contain the string “Props()” but will allow all other warning messages to be displayed. The first parameter, ignore, can also be set to once, which will result in a given message to be issued only once and then ignored on further instances.

See Python >>> Module Warnings for more information on using filterwarnings()

Module Documentation