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X Steam Tables for
MS Excel
or
OpenOffice.org
(OOo)
Calc
Steam and water properties according to the IAPWS IF97
standard formulation. (www.iapws.org)
A complete implementation. Uses short intuitive calling names. Everything is implemented as excel
scripts and stored inside a workbook. (No extra .DLL file or installation
required to run the excel spread sheet.)
The code are open source.
You are free to use, modify and distribute
the code as long as authorship is properly acknowledged (freeware).
Download it from the Download menu.
Advantages
-
Complete implementation. For a list of
calling functions se bellow.
-
No installation or .dll files needed,
everything is stored in the Excel, OpenOffice document.
-
Since the macros are stored in the
workbook calculations can be distrubuted to anyone without them
having to install any programs etc.
-
Simple to use
-
Fast calculations
Molliere chart produced with the steam tables.
(Download the excel chart from the download menu for free.)
Development
I appreciates all help I can get with the
steam tables. Se the
development page.
Calling syntax
A list of valid XSteam calling functions
are provided bellow and in the Excel/Open office Calc document. XSteam
functions take 1 or 2 arguments.
• Example: h_pt(1,20) Returns the enthalpy of water at 1 bar
and 20 degC
• Example: TSat_p(1) Returns the saturation temperature of
water at 1 bar.
For a list of valid Steam Table functions se bellow or XSteam for MS Excel
or the documentation that comes with the download.
Units and notation
Valid XSteam functions are listed in section 3. The notaions used in
XSteam are listed in the table bellow with the currently implemented.
The US unit set has not yet been tested yet. (BETA Release.) All
functions call unit conversion functions so you can easily adapted the
code to your own choice of units.
|
Notation |
Quantity |
Unit |
US Units (BETA) |
|
T |
Temperature |
°C |
°F |
|
p |
Pressure |
bar |
psi(a) |
|
h |
Enthalpy |
kJ/kg |
btu/lb |
|
v |
Specific volume |
m3/kg |
ft3/lb |
|
rho |
Density |
kg/ m3 |
lb/ft3 |
|
s |
Specific entropy
|
kJ/(kg °C) |
btu/(lb °F) |
|
u |
Specific internal energy
|
kJ/kg |
btu/lb |
|
Cp |
Specific isobaric heat
capacity |
kJ/(kg °C) |
btu/(lb °F) |
|
Cv |
Specific isochoric heat
capacity |
kJ/(kg °C) |
btu/(lb °F) |
|
w |
Speed of sound |
m/s |
ft/s |
|
my |
Viscosity |
Pa s |
lb/ft/hr |
|
tc |
Thermal Conductivity |
W/(m °C) |
btu/(h*ft*F) |
|
st |
Surface Tension |
N/m |
lb/ft |
|
x |
Vapour fraction (0-1) |
- |
- |
|
vx |
Vapour Volume Fraction (0-1) |
- |
- |
Valid calling functions
Temperature
|
Function |
Out |
|
Tsat_p |
Saturation temperature |
|
T_ph |
Temperture as a function of
pressure and enthalpy |
|
T_ps |
Temperture as a function of
pressure and entropy |
|
T_hs |
Temperture as a function of
enthalpy and entropy |
Pressure
|
Function |
Out |
|
psat_T |
Saturation pressure |
|
p_hs |
Pressure as a function of h
and s. |
|
p_hrho |
Pressure as a function of
enthalpy and density |
Enthalpy
|
Function |
Out |
|
hV_p |
Saturated vapour enthalpy |
|
hL_p |
Saturated liquid enthalpy |
|
hV_T |
Saturated vapour enthalpy |
|
hL_T |
Saturated liquid enthalpy |
|
h_pT |
Entalpy as a function of
pressure and temperature. |
|
h_ps |
Entalpy as a function of
pressure and entropy. |
|
h_px |
Entalpy as a function of
pressure and vapour fraction |
|
h_Tx |
Entalpy as a function of
temperature and vapour fraction |
|
h_prho |
Entalpy as a function of
pressure and density. Observe for low temperatures (liquid)
this equation has 2 solutions. (Not valid!!) |
Specific volume
|
Function |
Out |
|
vV_p |
Saturated vapour volume |
|
vL_p |
Saturated liquid volume |
|
vV_T |
Saturated vapour 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 |
Out |
|
rhoV_p |
Saturated vapour density |
|
rhoL_p |
Saturated liquid density |
|
rhoV_T |
Saturated vapour 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 |
Out |
|
sV_p |
Saturated vapour entropy |
|
sL_p |
Saturated liquid entropy |
|
sV_T |
Saturated vapour entropy |
|
sL_T |
Saturated liquid entropy |
|
s_pT |
Specific entropy as a function
of pressure and temperature (Returns saturated vapour
entalpy if mixture.) |
|
s_ph |
Specific entropy as a function
of pressure and enthalpy |
Specific internal energy
|
Function |
Out |
|
uV_p |
Saturated vapour internal
energy |
|
uL_p |
Saturated liquid internal
energy |
|
uV_T |
Saturated vapour 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 |
Out |
|
CpV_p |
Saturated vapour heat capacity
|
|
CpL_p |
Saturated liquid heat capacity
|
|
CpV_T |
Saturated vapour 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 |
Out |
|
CvV_p |
Saturated vapour isochoric
heat capacity |
|
CvL_p |
Saturated liquid isochoric
heat capacity |
|
CvV_T |
Saturated vapour 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 |
Out |
|
wV_p |
Saturated vapour speed of
sound |
|
wL_p |
Saturated liquid speed of
sound |
|
wV_T |
Saturated vapour 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
Viscosity is not part of IAPWS Steam
IF97. Equations from "Revised Release on the IAPWS Formulation 1985
for the Viscosity of Ordinary Water Substance", 2003 are used.
Viscosity in the mixed region (4) is
interpolated according to the density. This is not true since it
will be two fases.
|
Function |
Out |
|
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
Revised release on the IAPS
Formulation 1985 for the Thermal Conductivity of ordinary water
substance (IAPWS 1998)
|
Function |
Out |
|
tcL_p |
Saturated vapour thermal
conductivity |
|
tcV_p |
Saturated liquid thermal
conductivity |
|
tcL_T |
Saturated vapour 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
IAPWS Release on Surface Tension of
Ordinary Water Substance, September 1994
|
Function |
Out |
|
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 T |
Vapour fraction
|
Function |
Out |
|
x_ph |
Surface tension for two phase
water/steam as a function of T |
|
x_ps |
Surface tension for two phase
water/steam as a function of T |
Vapour
Volume Fraction
Observe that vapour volume fraction is
very sensitive. Vapour volume is about 1000 times greater than
liquid volume and therefore vapour volume fraction gets close to the
accurancy of IAPWS IF-97
|
Function |
Out |
|
vx_ph |
Vapour volume fraction as a
function of pressure and enthalpy |
|
vx_ps |
Vapour volume fraction as a
function of pressure and entropy. |
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