pyXSteam 0.4.8

pyXSteam is a port of the Matlab/Excel Package XSteam by Magnus Holmgren, www.x-eng.com to Python 3

XSteam

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

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

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: python setup.py test but make sure numpy is installed

To test if setup was successful, run python3 bin/pyXSteamDemo.py. This will require numpy and matplotlib to be installed. There are still (as of v0.4.2) some Errors in the speed of sound functions (w_ps), so be warned that they exceed the Error Range. Apart form accuracy errors, there should be no warnings.

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 bellow:

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
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
CpV_p	Saturated vapor heat capacity
CpL_p	Saturated liquid heat capacity
CpV_t	Saturated vapor heat capacity
CpL_t	Saturated liquid heat capacity
Cp_pt	Specific isobaric heat capacity as a function of pressure and temperature
Cp_ph	Specific isobaric heat capacity as a function of pressure and enthalpy
Cp_ps	Specific isobaric heat capacity as a function of pressure and entropy

Specific isochoric heat capacity

Function	Description
CvV_p	Saturated vapor isochoric heat capacity
CvL_p	Saturated liquid isochoric heat capacity
CvV_t	Saturated vapor isochoric heat capacity
CvL_t	Saturated liquid isochoric heat capacity
Cv_pt	Specific isochoric heat capacity as a function of pressure and temperature
Cv_ph	Specific isochoric heat capacity as a function of pressure and enthalpy
Cv_ps	Specific isochoric heat capacity as a function of pressure and entropy

Speed of sound

Function	Description
wV_p	Saturated vapor speed of sound
wL_p	Saturated liquid speed of sound
wV_t	Saturated vapor speed of sound
wL_t	Saturated liquid speed of sound
w_pt	Speed of sound as a function of pressure and temperature
w_ph	Speed of sound as a function of pressure and enthalpy
w_ps	Speed of sound as a function of pressure and entropy

Viscosity

Function	Description
my_pt	Viscosity as a function of pressure and temperature
my_ph	Viscosity as a function of pressure and enthalpy
my_ps	Viscosity as a function of pressure and entropy

Thermal Conductivity

Function	Description
tcL_p	Saturated vapor thermal conductivity
tcV_p	Saturated liquid thermal conductivity
tcL_t	Saturated vapor thermal conductivity
tcV_t	Saturated liquid thermal conductivity
tc_pt	Thermal conductivity as a function of pressure and temperature
tc_ph	Thermal conductivity as a function of pressure and enthalpy
tc_hs	Thermal conductivity as a function of enthalpy and entropy

Surface tension

Function	Description
st_t	Surface tension for two phase water/steam as a function of T
st_p	Surface tension for two phase water/steam as a function of p

vapor fraction

Function	Description
x_ph	vapor fraction as a function of pressure and enthalpy
x_ps	vapor fraction as a function of pressure and entropy

vapor volume fraction

Function	Description
vx_ph	vapor volume fraction as a function of pressure and enthalpy
vx_ps	vapor volume fraction as a function of pressure and entropy

Pressure along the Melting and Sublimation Curves

Function	Description
pmelt_t	Pressure along the melting curve as a function of temperature
vx_psubl_tps	Pressure along the sublimation curve as a function of temperature

Available Functions for Heavy Water

Function	Description
my_rhoT	Viscosity as a function of density and temperature
tc_rhoT	Thermal conductivity as a function of density and temperature