Sandlersteam

Digitized steam tables from Sandler's 5th ed.

Sandlersteam implements a python interface to the steam tables found in Appendix III of Chemical, Biochemical, and Engineering Thermodynamics (5th edition) by Stan Sandler (Wiley, USA). It should be used for educational purposes only.

The interface operates similarly to the IAPWS steam tables.

Installation

Sandlersteam is available via pip:

pip install sandlersteam

Usage

Command-line interface

Querying properties of steam and water:

$ sandlersteam state --T 200 --P 40              
THERMODYNAMIC STATE OF UNSATURATED STEAM/WATER:
  T = 200 C
  P = 40 MPa
  u = 825.55 kJ/kg
  v = 0.0011224 m3/kg
  s = 2.27635 kJ/kg-K
  h = 870.4 kJ/kg
$ sandlersteam state --T 200 --x 0.5
THERMODYNAMIC STATE OF SATURATED STEAM/WATER:
  T = 200 C
  P = 0.0015538 MPa
  u = 1722.98 kJ/kg
  v = 0.0642585 m3/kg
  s = 4.3816 kJ/kg-K
  h = 1822.82 kJ/kg
  quality x = 0.5
    uL = 850.65 kJ/kg, uV = 2595.3 kJ/kg
    vL = 0.001157 m3/kg, vV = 0.12736 m3/kg
    sL = 2.3309 kJ/kg-K, sV = 6.4323 kJ/kg-K
    hL = 852.45 kJ/kg, hV = 2793.2 kJ/kg

Generating LaTeX source for a table or a block:

$ sandlersteam latex --suphP 4.0 --output tmp.tex
Request completed: wrote output to tmp.tex
$ cat tmp.tex

\clearpage
\noindent THERMODYNAMIC PROPERTIES OF STEAM (Selected)\\*[1cm]
Superheated steam:\\*[0mm]
\noindent\begin{minipage}{0.6\textwidth}
\footnotesize\vspace{5mm}
\begin{center}
$P$ = 4.0 MPa\\*[1ex]
\begin{tabular}{>{\raggedleft}p{8mm}@{}p{5mm}>{\raggedleft}p{4mm}@{}p{10mm}>{\raggedleft}p{10mm}@{}p{3mm}>{\raggedleft}p{10mm}@{}p{3mm}>{\raggedleft\arraybackslash}p{3mm}@{}p{8mm}}
\toprule
\multicolumn{2}{c}{$T$~($^\circ$C)} & \multicolumn{2}{c}{$\hat{V}$} & \multicolumn{2}{c}{$\hat{U}$} & \multicolumn{2}{c}{$\hat{H}$} & \multicolumn{2}{c}{$\hat{S}$}\\
\toprule
\midrule
250 & .4 & 0 & .04978 & 2602 & .3 & 2801 & .4 & 6 & .0701 \\
275 &  & 0 & .05457 & 2667 & .9 & 2886 & .2 & 6 & .2285 \\
300 &  & 0 & .05884 & 2725 & .3 & 2960 & .7 & 6 & .3615 \\
350 &  & 0 & .06645 & 2826 & .7 & 3092 & .5 & 6 & .5821 \\
400 &  & 0 & .07341 & 2919 & .9 & 3213 & .6 & 6 & .7690 \\
450 &  & 0 & .08002 & 3010 & .2 & 3330 & .3 & 6 & .9363 \\
500 &  & 0 & .08643 & 3099 & .5 & 3445 & .3 & 7 & .0901 \\
600 &  & 0 & .09885 & 3279 & .1 & 3674 & .4 & 7 & .3688 \\
700 &  & 0 & .11095 & 3462 & .1 & 3905 & .9 & 7 & .6198 \\
800 &  & 0 & .12287 & 3650 & .0 & 4141 & .5 & 7 & .8502 \\
900 &  & 0 & .13469 & 3843 & .6 & 4382 & .3 & 8 & .0647 \\
1000 &  & 0 & .14645 & 4042 & .9 & 4628 & .7 & 8 & .2662 \\
1100 &  & 0 & .15817 & 4248 & .0 & 4880 & .6 & 8 & .4567 \\
1200 &  & 0 & .16987 & 4458 & .6 & 5138 & .1 & 8 & .6376 \\
1300 &  & 0 & .18156 & 4674 & .3 & 5400 & .5 & 8 & .8100 \\
\bottomrule
\end{tabular}
\end{center}
\end{minipage}

\noindent $\hat{V}\ [=]\ \mbox{m$^3$/kg}$; $\hat{U}\ [=]\ \mbox{kJ/kg}$; $\hat{H}\ [=]\ \mbox{kJ/kg}$; $\hat{S}\ [=]\ \mbox{kJ/kg-K}$\\*[1cm]

API

Below we create a State object to define a thermodynamic state for steam at 100 deg. C and 0.1 MPa:

>>> from sandlersteam.state import State
>>> state1 = State(T=100.0, P=0.1)
>>> state1.h  # enthalpy in kJ/kg
2676.2
>>> state1.u  # internal energy in kJ/kg
2506.7
>>> state1.v  # volume in m3/kg
1.6958
>>> state1.s  # entropy in kJ/kg-K
7.3614

Specifying a state requires values for two independent state variables. The state variables recognized by sandlersteam are:

• T temperature in C
• P pressure in MPa
• u specific internal energy in kJ/kg
• v specific volume in m³/kg
• h specific enthalpy in kJ/kg
• s specific entropy in kJ/kg
• x quality; mass fraction of vapor in a saturated vapor/liquid system (between 0 and 1)

Initializing a State instance with any two of these values set by keyword parameters results in the other properties receiving values by (bi)linear interpolation.

When specifying quality, a State objects acquires Liquid and Vapor attributes that each hold intensive, saturated single-phase property values. The property value attributes owned directly by the State object reflect the quality-weighted sum of the respective single-phase values:

>>> s = State(T=100,x=0.5)
>>> s.P
0.10135
>>> s.v
0.836972
>>> s.Vapor.v
1.6729
>>> s.Liquid.v
0.001044
>>> 0.5*(s.Vapor.v+s.Liquid.v)
0.836972

One can also import the SteamTables dictionary from the state state module and then generate LaTeX-compatible versions of either blocks in the superheated/subcooled steam tables or entire saturated steam stables, listed by temperature or pressure. For example:

>>> from sandlersteam.state import SteamTables as st
>>> print(st['suph'].to_latex(P=1.0))  # generates latex for the 1 MPa block of the superheated steam table

\begin{minipage}{0.6\textwidth}
\footnotesize\vspace{5mm}
\begin{center}
$P$ = 1.0 MPa\\*[1ex]
\begin{tabular}{>{\raggedleft}p{8mm}@{}p{5mm}>{\raggedleft}p{4mm}@{}p{10mm}>{\raggedleft}p{10mm}@{}p{3mm}>{\raggedleft}p{10mm}@{}p{3mm}>{\raggedleft\arraybackslash}p{3mm}@{}p{8mm}}
\toprule
\multicolumn{2}{c}{$T$~($^\circ$C)} & \multicolumn{2}{c}{$\hat{V}$} & \multicolumn{2}{c}{$\hat{U}$} & \multicolumn{2}{c}{$\hat{H}$} & \multicolumn{2}{c}{$\hat{S}$}\\
\toprule
\midrule
179 & .91 & 0 & .19444 & 2583 & .6 & 2778 & .1 & 6 & .5865 \\
200 &  & 0 & .2060 & 2621 & .9 & 2827 & .9 & 6 & .6940 \\
250 &  & 0 & .2327 & 2709 & .9 & 2942 & .6 & 6 & .9247 \\
300 &  & 0 & .2579 & 2793 & .2 & 3051 & .2 & 7 & .1229 \\
350 &  & 0 & .2825 & 2875 & .2 & 3157 & .7 & 7 & .3011 \\
400 &  & 0 & .3066 & 2957 & .3 & 3263 & .9 & 7 & .4651 \\
500 &  & 0 & .3541 & 3124 & .4 & 3478 & .5 & 7 & .7622 \\
600 &  & 0 & .4011 & 3296 & .8 & 3697 & .9 & 8 & .0290 \\
700 &  & 0 & .4478 & 3475 & .3 & 3923 & .1 & 8 & .2731 \\
800 &  & 0 & .4943 & 3660 & .4 & 4154 & .7 & 8 & .4996 \\
900 &  & 0 & .5407 & 3852 & .2 & 4392 & .9 & 8 & .7118 \\
1000 &  & 0 & .5871 & 4050 & .5 & 4637 & .6 & 8 & .9119 \\
1100 &  & 0 & .6335 & 4255 & .1 & 4888 & .6 & 9 & .1017 \\
1200 &  & 0 & .6798 & 4465 & .6 & 5145 & .4 & 9 & .2822 \\
1300 &  & 0 & .7261 & 4681 & .3 & 5407 & .4 & 9 & .4543 \\
\bottomrule
\end{tabular}
\end{center}
\end{minipage}

This renders as

Release History

• 0.5.1:
  • units bugfix after cli introduction
• 0.5.0:
  • command-line interface
• 0.4.2:
  • RandomState class introduced
• 0.3.3:
  • Included subcooled liquid data in the Request capability
• 0.2.1
  • bugfix: set left and right parameters in all numpy.interp() to numpy.nan to override the pinning default for extrapolated values
• 0.2.0
  • Added the Request class for dynamically selecting and outputting (as LaTeX) steam table blocks requested by (for example) exam problems
• 0.1.9
  • bugfix: allows for specification of x as 0
• 0.1.8
  • Update readme
• 0.1.7
  • Updated pandas indexing for saturated table LaTeX printing
• 0.1.5
  • Updated interpolators
• 0.1.1
  • Updated pyproject.toml and README.md
• 0.1.0
  • Initial version

Meta

Cameron F. Abrams – cfa22@drexel.edu

Distributed under the MIT license. See LICENSE for more information.

https://github.com/cameronabrams

Contributing

1. Fork it (https://github.com/cameronabrams/sandlersteam/fork)
2. Create your feature branch (git checkout -b feature/fooBar)
3. Commit your changes (git commit -am 'Add some fooBar')
4. Push to the branch (git push origin feature/fooBar)
5. Create a new Pull Request