Merge pull request #8511 from NREL/8492_FuellCell_Test

#8492 #8513 - Add a FuelCellElectricGenerator Unit Test and do not zero out Constant Skin Loss Rate in Generator:FuelCell:PowerModule

doc/input-output-reference/src/overview/group-electric-load-center-generator.tex

@@ -3238,6 +3238,10 @@ \subsubsection{Outputs}\label{outputs-9-001}
   HVAC,Sum, Generator Fuel Cell Model Iteration Count {[]}
 \item
   HVAC,Sum,Generator Root Solver Iteration Count {[]}
+\item
+  HVAC,Average,Generator Number of Cycles {[]}
+\item
+  HVAC,Average,Generator Power Module Skin Heat Loss Rate {[}W{]}
 \end{itemize}
 
 \paragraph{Generator Air Inlet Temperature {[}C{]}}\label{generator-air-inlet-temperature-c}
@@ -3412,6 +3416,16 @@ \subsubsection{Outputs}\label{outputs-9-001}
 
 This is the flow of condensed water in kmol/s.
 
+\paragraph{Generator Number of Cycles {[]}}\label{generator-number-of-cycles}
+
+This is the number of start-stop cycles that the fuel cell power module has experienced so far.
+It is initialized to the value of \hyperref[field-number-of-stops-at-start-of-simulation]{Number of Stops at Start of Simulation} provided in the \hyperref[generatorfuelcellpowermodule]{Generator:FuelCell:PowerModule} object.
+
+\paragraph{Generator Power Module Skin Heat Loss Rate {[}W{]}}\label{generator-power-module-skin-heat-loss-rate-w}
+
+This is the which is the rate of energy lost to the surroundings via the skin of the fuel cell power module.
+
+
 \subsection{Generator:FuelCell:PowerModule}\label{generatorfuelcellpowermodule}
 
 This object is used to describe the core power module subsystem of the FC. This includes the fuel cell stack, fuel reformer, and whatever ancillary devices are included inside. If the model has multiple FC generators that are of the exact same type, then only one of these objects is needed and all the \hyperref[generatorfuelcell]{Generator:FuelCell} can reference it. The model uses a number of curves to describe operating performance. Input data for specific models of FC are not yet available but will be produced by IEA Annex 42 and should be available in the future.

src/EnergyPlus/FuelCellElectricGenerator.cc

@@ -266,7 +266,8 @@ namespace FuelCellElectricGenerator {
 
                 state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.NomEff = NumArray(1);
                 state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.NomPel = NumArray(2);
-                state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.NumCycles = NumArray(3);
+                state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.NumCyclesAtStart = NumArray(3);
+                state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.NumCycles = state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.NumCyclesAtStart;
                 state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.CyclingDegradRat = NumArray(4);
                 state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.NumRunHours = NumArray(5);
                 state.dataFuelCellElectGen->FuelCell(thisFuelCell).FCPM.OperateDegradRat = NumArray(6);
@@ -1330,6 +1331,20 @@ namespace FuelCellElectricGenerator {
                                 "System",
                                 "Sum",
                                 this->Name);
+
+            SetupOutputVariable(state, "Generator Number of Cycles",
+                                OutputProcessor::Unit::None,
+                                this->Report.NumCycles,
+                                "System",
+                                "Average",
+                                this->Name);
+
+            SetupOutputVariable(state, "Generator Power Module Skin Heat Loss Rate",
+                                OutputProcessor::Unit::W,
+                                this->Report.FCPMSkinLoss,
+                                "System",
+                                "Average",
+                                this->Name);
         }
     }
 
@@ -3194,7 +3209,7 @@ namespace FuelCellElectricGenerator {
             this->AirSup.TairIntoBlower = 0.0;
             this->AirSup.QskinLoss = 0.0;
             this->AirSup.QintakeRecovery = 0.0;
-            this->FCPM.NumCycles = 0;
+            this->FCPM.NumCycles = this->FCPM.NumCyclesAtStart;
             this->FCPM.Pel = 0.0;
             this->FCPM.PelLastTimeStep = 0.0;
             this->FCPM.Eel = 0.0;
@@ -3340,7 +3355,10 @@ namespace FuelCellElectricGenerator {
                 cell.AirSup.QskinLoss = 0.0;
                 cell.WaterSup.QskinLoss = 0.0;
                 cell.AuxilHeat.QskinLoss = 0.0;
-                cell.FCPM.QdotSkin = 0.0;
+                if (cell.FCPM.SkinLossMode != DataGenerators::SkinLoss::ConstantRate) {
+                    // If Constant Skin Loss Rate, then do not zero out
+                    cell.FCPM.QdotSkin = 0.0;
+                }
                 cell.Report.SkinLossConvect = 0.0;
                 cell.Report.SkinLossRadiat = 0.0;
                 cell.AuxilHeat.QairIntake = 0.0;
@@ -3484,6 +3502,8 @@ namespace FuelCellElectricGenerator {
 
         this->Report.SeqSubstIterations = this->FCPM.SeqSubstitIter;     // number of iterations in FuelCell loop
         this->Report.RegulaFalsiIterations = this->FCPM.RegulaFalsiIter; // number of iterations in Tproduct gas solving
+        this->Report.NumCycles = this->FCPM.NumCycles;                   // number of start-stop cycles
+        this->Report.FCPMSkinLoss = this->FCPM.QdotSkin;                 // Skin loss of power module
 
         this->Report.ACancillariesPower = this->FCPM.PelancillariesAC;
         this->Report.ACancillariesEnergy = this->FCPM.PelancillariesAC * DataHVACGlobals::TimeStepSys * DataGlobalConstants::SecInHour;

src/EnergyPlus/FuelCellElectricGenerator.hh

@@ -68,6 +68,7 @@ namespace FuelCellElectricGenerator {
         int EffCurveID;             // pointer to curve for efficiency
         Real64 NomEff;              // nominal efficiency
         Real64 NomPel;              // nominal power rate at rating point
+        int NumCyclesAtStart;       // number of start stop cycles at beggining of simulation (user input)
         int NumCycles;              // number of start stop cycles
         Real64 CyclingDegradRat;    // rate of degradation from cycles
         Real64 NumRunHours;         // number of hours of operation
@@ -437,6 +438,8 @@ namespace FuelCellElectricGenerator {
         Real64 ThermalEfficiency;
         Real64 OverallEfficiency;
         Real64 ExergyEfficiency;
+        int NumCycles;               // Number of start-stop cycles
+        Real64 FCPMSkinLoss;         // Power module skin losses [W]
 
         // Default Constructor
         FCReportDataStruct()
@@ -450,7 +453,8 @@ namespace FuelCellElectricGenerator {
               WaterVaporFractExh(0.0), CondensateRate(0.0), SeqSubstIterations(0), RegulaFalsiIterations(0), ACancillariesPower(0.0),
               ACancillariesEnergy(0.0), PCUlosses(0.0), DCPowerGen(0.0), DCPowerEff(0.0), ElectEnergyinStorage(0.0), StoredPower(0.0),
               StoredEnergy(0.0), DrawnPower(0.0), DrawnEnergy(0.0), SkinLossPower(0.0), SkinLossEnergy(0.0), SkinLossConvect(0.0),
-              SkinLossRadiat(0.0), ElectEfficiency(0.0), ThermalEfficiency(0.0), OverallEfficiency(0.0), ExergyEfficiency(0.0)
+              SkinLossRadiat(0.0), ElectEfficiency(0.0), ThermalEfficiency(0.0), OverallEfficiency(0.0), ExergyEfficiency(0.0), NumCycles(0),
+              FCPMSkinLoss(0.0)
         {
         }
     };