XSteam

Original Released by Magnus Holmgren for Matlab and Excel: http://xsteam.sourceforge.net and/or http://www.x-eng.com

At this github repository you can find the/a matlab version.

A .NET implementation is availible thanks to the work of rogerlew here: XSteamNET.

XSteam provides (mostly) accurate steam and water properties from 0 - 1000 bar and from 0 - 2000 °C according to the IAPWS release IF-97. For accuracy of the functions in different regions see IF-97 Page 4

Also includes thermal conductivity and viscosity, which are not part of the IF97 release.

• Thermal Conductivity: (IAPWS 1998) http://www.iapws.org/relguide/ThCond.pdf
• Viscosity: (2003)

Some effort has been made to include the refined function of more recent releases and also functions for calculations on heavy water. This includes:

• IAPWS R4
• IAPWS R14

Contributors to pyXSteam

In chronological order:

• IAPWS
• Magnus Holmgren
• drunsinn
• mohit0749
• gonmolina
• xjtu-blacksmith
• sebastiantuinstra

Requirements

There are no requirements for installing pyXSteam with Python 3.6 and up.

Tests require numpy, demos require numpy and matplotlib

Install

run python3 setup.py install

To run unittests you need two additional packages: pytest and numpy. After installing both, just run pytest in the base directory. The tests use some fixed values from the documentation to make sure that every coefficient and formula works as intended.

To test if setup was successful, run python3 bin/pyXSteamDemo.py. This will require numpy and matplotlib to be installed.

Nomenclature

All Functions follow the same naming schema: First the wanted property, then a underscore _, then the wanted input properties Example: t_ph is temperature as a function of pressure and enthalpy. For a list of valid functions se below:

| Property | Description | |----------|--------------------------------------------------------------| | t | Temperature (°C or °F) | | p | Pressure (bar or psi) | | h | Enthalpy (kJ/kg or btu/lb) | | v | Specific volume (m3/kg or ft^3/lb) | | rho | Density (kg/m3 or lb/ft^3) | | s | Specific entropy (kJ/(kg °C) or btu/(lb °F)) | | u | Specific internal energy (kJ/kg or btu/lb) | | Cp | Specific isobaric heat capacity (kJ/(kg °C) or btu/(lb °F)) | | Cv | Specific isochoric heat capacity (kJ/(kg °C) or btu/(lb °F)) | | w | Speed of sound (m/s or ft/s) | | my | Viscosity (N s/m^2 or lbm/ft/hr) | | tc | Thermal Conductivity (W/(m °C) or btu/(h ft °F)) | | st | Surface Tension (N/m or lb/ft) | | x | Vapor fraction | | vx | Vapor Volume Fraction |

Usage

Simple Example:

from pyXSteam.XSteam import XSteam
steamTable = XSteam(XSteam.UNIT_SYSTEM_MKS)
print(steamTable.hL_p(220.0))

By using the unitSystem Parameter, you can tell XSteam witch Unit System you are using.

steamTable = XSteam(XSteam.UNIT_SYSTEM_MKS) # m/kg/sec/°C/bar/W
steamTable = XSteam(XSteam.UNIT_SYSTEM_FLS) # ft/lb/sec/°F/psi/btu
steamTable = XSteam(XSteam.UNIT_SYSTEM_BARE) # m/kg/sec/K/MPa/W

To enable logging, add the following lines to your code:

import logging
logging.basicConfig(level=logging.INFO)

or alternatively

import logging
logger = logging.getLogger('pyXSteam')
logger.setLevel(logging.DEBUG)
sh = logging.StreamHandler()
sh.setFormatter(logging.Formatter('%(name)s - %(levelname)s - %(message)s'))
logger.addHandler(sh)

Available Functions

Temperature

| Function | Description | |----------|----------------------------------------------------| | tsat_p | Saturation temperature | | t_ph | Temperature as a function of pressure and enthalpy | | t_ps | Temperature as a function of pressure and entropy | | t_hs | Temperature as a function of enthalpy and entropy |

Pressure

| Function | Description | |----------|----------------------------------------------------------------------------------------------------------------| | psat_t | Saturation pressure | | p_hs | Pressure as a function of h and s. | | p_hrho | Pressure as a function of h and rho. Very inaccurate for solid water region since it's almost incompressible! | | pmelt_t | Pressure as a function of temperature along the melting curve. Optional parameter to select ice region | | psubl_t | Pressure as a function of temperature along the sublimation curve. |

Enthalpy

| Function | Description | |----------|---------------------------------------------------------------------------------------------------------------------| | hV_p | Saturated vapor enthalpy | | hL_p | Saturated liquid enthalpy | | hV_t | Saturated vapor enthalpy | | hL_t | Saturated liquid enthalpy | | h_pt | Enthalpy as a function of pressure and temperature | | h_ps | Enthalpy as a function of pressure and entropy | | h_px | Enthalpy as a function of pressure and vapor fraction | | h_prho | Enthalpy as a function of pressure and density. Observe for low temperatures (liquid) this equation has 2 solutions | | h_tx | Enthalpy as a function of temperature and vapor fraction |

Specific volume

| Function | Description | |----------|-----------------------------------------------------------| | vV_p | Saturated vapor volume | | vL_p | Saturated liquid volume | | vV_t | Saturated vapor volume | | vL_t | Saturated liquid volume | | v_pt | Specific volume as a function of pressure and temperature | | v_ph | Specific volume as a function of pressure and enthalpy | | v_ps | Specific volume as a function of pressure and entropy |

Density

| Function | Description | |----------|---------------------------------------------------| | rhoV_p | Saturated vapor density | | rhoL_p | Saturated liquid density | | rhoV_t | Saturated vapor density | | rhoL_t | Saturated liquid density | | rho_pt | Density as a function of pressure and temperature | | rho_ph | Density as a function of pressure and enthalpy | | rho_ps | Density as a function of pressure and entropy |

Specific entropy

| Function | Description | |----------|----------------------------------------------------------------------------------------------------------| | sV_p | Saturated vapor entropy | | sL_p | Saturated liquid entropy | | sV_t | Saturated vapor entropy | | sL_t | Saturated liquid entropy | | s_pt | Specific entropy as a function of pressure and temperature (Returns saturated vapor enthalpy if mixture) | | s_ph | Specific entropy as a function of pressure and enthalpy |

Specific internal energy

| Function | Description | |----------|--------------------------------------------------------------------| | uV_p | Saturated vapor internal energy | | uL_p | Saturated liquid internal energy | | uV_t | Saturated vapor internal energy | | uL_t | Saturated liquid internal energy | | u_pt | Specific internal energy as a function of pressure and temperature | | u_ph | Specific internal energy as a function of pressure and enthalpy | | u_ps | Specific internal energy as a function of pressure and entropy |

Specific isobaric heat capacity

| Function | Description