Merge pull request #1800 from khinkelman/issue1793_steamDocumentation

Issue1793 steam documentation

IBPSA/Media/Steam.mo

@@ -8,6 +8,7 @@ package Steam
     reducedX=true,
     fixedX=true,
     FluidConstants={Modelica.Media.IdealGases.Common.FluidData.H2O},
+    ThermoStates=Modelica.Media.Interfaces.Choices.IndependentVariables.pTX,
     reference_T=273.15,
     reference_p=101325,
     reference_X={1},
@@ -125,8 +126,8 @@ redeclare replaceable function extends specificEnthalpy
     constant Temperature TMean =  4.15555698340926E+02 "Mean temperature";
     constant Real pSD = 1.13236055019318E+05 "Normalization value";
     constant Real TSD = 1.32971013463839E+01 "Normalization value";
-    AbsolutePressure pHat;
-    Temperature THat;
+    Modelica.Units.SI.PressureDifference pHat;
+    Modelica.Units.SI.TemperatureDifference THat;
 algorithm
   pHat := (state.p - pMean)/pSD;
   THat := (state.T - TMean)/TSD;
@@ -170,8 +171,8 @@ redeclare replaceable function extends specificEntropy
     constant Temperature TMean =  4.15555698340926E+02 "Mean temperature";
     constant Real pSD = 1.13236055019318E+05 "Normalization value";
     constant Real TSD = 1.32971013463839E+01 "Normalization value";
-    AbsolutePressure pHat;
-    Temperature THat;
+    Modelica.Units.SI.PressureDifference pHat;
+    Modelica.Units.SI.TemperatureDifference THat;
 algorithm
   pHat := (state.p - pMean)/pSD;
   THat := (state.T - TMean)/TSD;
@@ -728,7 +729,7 @@ function temperature_ph
     constant Temperature TMean =  4.15555698340926E+02 "Mean temperature";
     constant Real pSD = 1.13236055019318E+05 "Normalization value";
     constant Real TSD = 1.32971013463839E+01 "Normalization value";
-    AbsolutePressure pHat;
+    Modelica.Units.SI.PressureDifference pHat;
 algorithm
   pHat := (p - pMean)/pSD;
   T := b[1] + b[2]*pHat + b[3]*h;
@@ -773,8 +774,8 @@ function temperature_ps
     constant Temperature TMean =  4.15555698340926E+02 "Mean temperature";
     constant Real pSD = 1.13236055019318E+05 "Normalization value";
     constant Real TSD = 1.32971013463839E+01 "Normalization value";
-    AbsolutePressure pHat;
-    Temperature THat;
+    Modelica.Units.SI.PressureDifference pHat;
+    Modelica.Units.SI.TemperatureDifference THat;
 algorithm
   pHat := (p - pMean)/pSD;
   THat := (s - a[1] - pHat*(a[2] + a[4]*pHat))/(a[3] + a[5]*pHat);
@@ -818,10 +819,14 @@ function rho_pT "Density as function of temperature and pressure"
   Modelica.Media.Common.GibbsDerivs g
     "Dimensionless Gibbs function and derivatives w.r.t. pi and tau";
   SpecificHeatCapacity R "Specific gas constant of water vapor";
+  function g2_smooth
+    extends Modelica.Media.Water.IF97_Utilities.BaseIF97.Basic.g2;
+    annotation(smoothOrder=2);
+  end g2_smooth;
 algorithm
   R := Modelica.Media.Water.IF97_Utilities.BaseIF97.data.RH2O;
   // Region 2 properties
-  g := Modelica.Media.Water.IF97_Utilities.BaseIF97.Basic.g2(p, T);
+  g := g2_smooth(p, T);
   rho := p/(R*T*g.pi*g.gpi);
   annotation (
     Inline=true,
@@ -847,7 +852,6 @@ algorithm
         region=2);
   annotation (Inline=true);
 end pressure_dT;
-
   annotation (Icon(graphics={
       Line(
         points={{50,30},{30,10},{50,-10},{30,-30}},
@@ -913,9 +917,42 @@ steam heating processes involving low and medium pressure steam.
 properties of water and steam,&rdquo; <i>J. Eng. Gas Turbines Power</i>, vol. 122, no.
 1, pp. 150&ndash;180, 2000.
 </p>
+<p>
+Kathryn Hinkelman, Saranya Anbarasu, Michael Wetter, Antoine Gautier, Wangda Zuo. 2022. 
+&ldquo;A Fast and Accurate Modeling Approach for Water and Steam 
+Thermodynamics with Practical Applications in District Heating System Simulation,&rdquo; 
+<i>Energy</i>, 254(A), pp. 124227.
+<a href=\\\"https://doi.org/10.1016/j.energy.2022.124227\\\">10.1016/j.energy.2022.124227</a>
+</p>
+<p>
+Kathryn Hinkelman, Saranya Anbarasu, Michael Wetter, Antoine Gautier, Baptiste Ravache, Wangda Zuo 2022. 
+&ldquo;Towards Open-Source Modelica Models For Steam-Based District Heating Systems.&rdquo; 
+<i>Proc. of the 1st International Workshop On Open Source Modelling And Simulation Of 
+Energy Systems (OSMSES 2022)</i>, Aachen, German, April 4-5, 2022.
+<a href=\\\"https://doi.org/10.1109/OSMSES54027.2022.9769121\\\">10.1109/OSMSES54027.2022.9769121</a>
+</p>
 </html>", revisions="<html>
 <ul>
 <li>
+September 29, 2023, by Kathryn Hinkelman:<br/>
+Added publication references.
+</li>
+<li>
+March 10, 2023, by Saranya Anbarasu:<br/>
+Changed the variable type definition of <code>pHat</code> and <code>THat</code> 
+from absolute to <code>Modelica.Units.SI.PressureDifference</code> and 
+<code>Modelica.Units.SI.TemperatureDifference</code> to prevent min/max 
+assertion errors during initilization.
+</li>
+<li>
+May 9, 2022, by David Blum:<br/>
+In function <code>rho_pT</code>, created and used new function extending
+<code>Modelica.Media.Water.IF97_Utilities.BaseIF97.Basic.g2</code> with an
+annotation <code>smoothOrder=2</code>.  This is to specifically pass on the 
+<code>smoothOrder=2</code> annotion placed on <code>rho_pT</code> to 
+the <code>g2</code> function.
+</li>
+<li>
 April 13, 2021, by Kathryn Hinkelman:<br/>
 Changed pressure from constant to variable and reduced applicable
 pressure-temperature range to improve accuracy of polynomial approximations.