Use max of Tmin and Ttriple to build tables; closes #738

CoolProp · Aug 2, 2015 · 0afd230 · 0afd230
1 parent 55143c0
commit 0afd230
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Showing 2 changed files with 8 additions and 6 deletions.
diff --git a/src/Backends/Tabular/TabularBackends.cpp b/src/Backends/Tabular/TabularBackends.cpp
@@ -120,7 +120,8 @@ void CoolProp::PureFluidSaturationTableData::build(shared_ptr<CoolProp::Abstract
     // ------------------------
     // Actually build the table
     // ------------------------
-    AS->update(QT_INPUTS, 0, AS->Ttriple());
+    CoolPropDbl Tmin = std::max(AS->Ttriple(), AS->Tmin());
+    AS->update(QT_INPUTS, 0, Tmin);
     CoolPropDbl p_triple = AS->p();
     CoolPropDbl p, pmin = p_triple, pmax = 0.9999*AS->p_critical();
     for (std::size_t i = 0; i < N-1; ++i)

diff --git a/src/Backends/Tabular/TabularBackends.h b/src/Backends/Tabular/TabularBackends.h
@@ -292,7 +292,7 @@ class PureFluidSaturationTableData{
          */
         double first_saturation_deriv(parameters Of1, parameters Wrt1, int Q, double val, std::size_t i)
         {
-            if (i < 2 || i > TL.size() - 2){throw ValueError("Invalid index to calc_first_saturation_deriv in TabularBackends");}
+            if (i < 2 || i > TL.size() - 2){throw ValueError(format("Invalid index (%d) to calc_first_saturation_deriv in TabularBackends",i));}
             std::vector<double> *x, *y;
             // Connect pointers for each vector
             switch(Wrt1){
@@ -517,8 +517,9 @@ class LogPHTable : public SinglePhaseGriddedTableData
             if (this->AS.get() == NULL){
                 throw ValueError("AS is not yet set");
             }
+            CoolPropDbl Tmin = std::max(AS->Ttriple(), AS->Tmin());
             // Minimum enthalpy is the saturated liquid enthalpy
-            AS->update(QT_INPUTS, 0, AS->Ttriple());
+            AS->update(QT_INPUTS, 0, Tmin);
             xmin = AS->hmolar(); ymin = AS->p();
 
             // Check both the enthalpies at the Tmax isotherm to see whether to use low or high pressure
@@ -562,9 +563,9 @@ class LogPTTable : public SinglePhaseGriddedTableData
         void set_limits(){
             if (this->AS.get() == NULL){
                 throw ValueError("AS is not yet set");
-            }            
-            xmin = AS->Ttriple();
-            AS->update(QT_INPUTS, 0, AS->Ttriple());
+            }
+            CoolPropDbl Tmin = std::max(AS->Ttriple(), AS->Tmin());
+            AS->update(QT_INPUTS, 0, Tmin);
             ymin = AS->p();
 
             xmax = AS->Tmax()*1.499; ymax = AS->pmax();