#11567: ZoneHVAC:HybridUnitaryHVAC - Add choice to optimize Supply Temperature

doc/input-output-reference/src/overview/group-zone-forced-air-units.tex

@@ -4431,9 +4431,8 @@ \subsubsection{Inputs}
 \paragraph{Field: Third Fuel Type}
 This alpha field specifies the fuel type associated with the \hyperref[tablelookup]{Table:Lookup} object specified in field ''System Third Fuel Consumption Lookup Table``. Valid choices include: None, Electricity, NaturalGas, Propane, FuelOilNo1, FuelOilNo2, Diesel, Gasoline, Coal, OtherFuel1, OtherFuel2, Steam, \hyperref[districtheating]{DistrictHeatingWater} and \hyperref[districtcooling]{DistrictCooling}. If this field is blank, the default second fuel type is None.
 
-\paragraph{Field: Objective Function to Minimize}
-In each time step ZoneHVAC:HybridUnitaryHVAC will choose one or more combinations of the controlled independent variables, subject to constraints, so as to best satisfy sensible load, latent load, and scheduled ventilation with the least amount of resource consumption. This alpha field specifies which resource will be minimized by the optimization.  Valid choices include: Electricity Use, Second Fuel Use, Third Fuel Use, and Water Use.  If this field is blank, the objective function will minimize electricity use.
-
+\paragraph{Field: Objective Function to Optimize}
+In each time step ZoneHVAC:HybridUnitaryHVAC will choose one or more combinations of the controlled independent variables, subject to constraints, so as to best satisfy sensible load, latent load, and scheduled ventilation with the least amount of resource consumption. This alpha field specifies which resource will be optimized.  Valid choices include: Electricity Use, Second Fuel Use, Third Fuel Use, Water Use, and Supply Temperature.  If this field is blank, the default objective function to optimize is Electricity Use.
 
 \paragraph{Field: Design Specification Outdoor Air Object Name}
 This alpha field specifies the name of a \hyperref[designspecificationoutdoorair]{DesignSpecification:OutdoorAir} object which specifies the a schedule for the required standard density volume of outdoor air. If this field is blank, the system may still supply outdoor air, if it is capable, when doing so is the most efficient way to satisfy other constraints.

idd/Energy+.idd.in

@@ -37524,7 +37524,7 @@ ZoneHVAC:HybridUnitaryHVAC,
         \type object-list
         \object-list ScheduleNames
     A8, \field Method to Choose Controlled Inputs and Part Runtime Fraction
-        \note Select the method that will be used to choose operating mode(s), supply air flow rate(s), outdoor air fraction(s) and part runtime fraction(s) in each time step. "Automatic" = chooses controlled inputs and part runtime fraction(s) to minimize resource use within each time step while best satisfying requested sensible cooling, dehumidification and ventilation, and subject to constraints. "User Defined" = EMS will be used to choose controlled inputs and part runtime fraction(s) in each time step. If this field is blank, default to "Automatic".
+        \note Select the method that will be used to choose operating mode(s), supply air flow rate(s), outdoor air fraction(s) and part runtime fraction(s) in each time step. "Automatic" = chooses controlled inputs and part runtime fraction(s) to optimize resource use within each time step while best satisfying requested sensible cooling, dehumidification and ventilation, and subject to constraints. "User Defined" = EMS will be used to choose controlled inputs and part runtime fraction(s) in each time step. If this field is blank, default to "Automatic".
         \type choice
         \key Automatic
         \key User Defined
@@ -37640,14 +37640,15 @@ ZoneHVAC:HybridUnitaryHVAC,
         \note Select the fuel type associated with field: "System Third Fuel Consumption Lookup Table" in each mode.
         \note If this field is blank, default third fuel type = None.
         \default None
-   A18, \field Objective Function to Minimize
+   A18, \field Objective Function to Optimize
         \type choice
         \key Electricity Use
         \key Second Fuel Use
         \key Third Fuel Use
         \key Water Use
-        \note In each time step, controlled variables will be chosen to minimize the selection in this field, subject to constraints.
-        \note If this field is blank, the objective function will minimize electricity use.
+        \key Supply Temperature
+        \note In each time step, controlled variables will be chosen to optimize the selection in this field, subject to constraints.
+        \note If this field is blank, the default objective function to optimize is Electricity Use.
         \default Electricity Use
    A19, \field Design Specification Outdoor Air Object Name
         \type object-list

src/EnergyPlus/HybridEvapCoolingModel.cc

@@ -1251,6 +1251,8 @@ namespace HybridEvapCoolingModel {
         bool DidWeMeetHumidification = false;
         bool DidWePartlyMeetLoad = false;
         Real64 OptimalSetting_RunFractionTotalFuel = IMPLAUSIBLE_POWER;
+        Real64 OptimalSetting_RunFractionSupplyTemperature =
+            CoolingRequested ? std::numeric_limits<Real64>::max() : std::numeric_limits<Real64>::min();
         Real64 Tma;
         Real64 Wma;
         Real64 Hsa;
@@ -1511,37 +1513,60 @@ namespace HybridEvapCoolingModel {
 
             // Calculate partload fraction required to meet all requirements
             // Fraction can be above 1 meaning its not able to do it completely in a time step
-            Real64 PartRuntimeFraction = CalculatePartRuntimeFraction(MinOA_Msa,
-                                                                      thisSetting.Supply_Air_Ventilation_Volume * state.dataEnvrn->StdRhoAir,
-                                                                      StepIns.RequestedCoolingLoad,
-                                                                      StepIns.RequestedHeatingLoad,
-                                                                      SensibleRoomORZone,
-                                                                      StepIns.ZoneDehumidificationLoad,
-                                                                      StepIns.ZoneMoistureLoad,
-                                                                      latentRoomORZone);
-
-            Real64 RunFractionTotalFuel;
+            thisSetting.Runtime_Fraction = CalculatePartRuntimeFraction(MinOA_Msa,
+                                                                        thisSetting.Supply_Air_Ventilation_Volume * state.dataEnvrn->StdRhoAir,
+                                                                        StepIns.RequestedCoolingLoad,
+                                                                        StepIns.RequestedHeatingLoad,
+                                                                        SensibleRoomORZone,
+                                                                        StepIns.ZoneDehumidificationLoad,
+                                                                        StepIns.ZoneMoistureLoad,
+                                                                        latentRoomORZone);
+
+            Real64 RunFractionTotalFuel(0);
+            Real64 RunFractionSupplyTemperature(0);
             switch (ObjectiveFunction) {
             default:
             case ObjectiveFunctionType::ElectricityUse:
-                RunFractionTotalFuel = thisSetting.ElectricalPower * PartRuntimeFraction;
+                RunFractionTotalFuel = thisSetting.ElectricalPower * thisSetting.Runtime_Fraction;
                 break;
             case ObjectiveFunctionType::SecondFuelUse:
-                RunFractionTotalFuel = thisSetting.SecondaryFuelConsumptionRate * PartRuntimeFraction;
+                RunFractionTotalFuel = thisSetting.SecondaryFuelConsumptionRate * thisSetting.Runtime_Fraction;
                 break;
             case ObjectiveFunctionType::ThirdFuelUse:
-                RunFractionTotalFuel = thisSetting.ThirdFuelConsumptionRate * PartRuntimeFraction;
+                RunFractionTotalFuel = thisSetting.ThirdFuelConsumptionRate * thisSetting.Runtime_Fraction;
                 break;
             case ObjectiveFunctionType::WaterUse:
-                RunFractionTotalFuel = thisSetting.WaterConsumptionRate * PartRuntimeFraction;
+                RunFractionTotalFuel = thisSetting.WaterConsumptionRate * thisSetting.Runtime_Fraction;
+                break;
+            case ObjectiveFunctionType::SupplyTemperature:
+                RunFractionSupplyTemperature = thisSetting.SupplyAirTemperature * thisSetting.Runtime_Fraction;
                 break;
             }
-            thisSetting.Runtime_Fraction = PartRuntimeFraction; //
 
             if (Conditioning_load_met && Humidification_load_met) {
-                // store best performing mode
-                if (RunFractionTotalFuel < OptimalSetting_RunFractionTotalFuel) {
+                bool store_best_performing_mode = false;
+
+                if (ObjectiveFunction == ObjectiveFunctionType::SupplyTemperature) {
+                    if (CoolingRequested && RunFractionSupplyTemperature < OptimalSetting_RunFractionSupplyTemperature) {
+                        store_best_performing_mode = true;
+                        OptimalSetting_RunFractionSupplyTemperature = RunFractionSupplyTemperature;
+                    }
+                    if (HeatingRequested && RunFractionSupplyTemperature > OptimalSetting_RunFractionSupplyTemperature) {
+                        store_best_performing_mode = true;
+                        OptimalSetting_RunFractionSupplyTemperature = RunFractionSupplyTemperature;
+                    }
+                    // fall back to ElectricityUse since ventilation-only is just fan operation
+                    if (!CoolingRequested && !HeatingRequested && VentilationRequested &&
+                        RunFractionTotalFuel < OptimalSetting_RunFractionTotalFuel) {
+                        store_best_performing_mode = true;
+                        OptimalSetting_RunFractionTotalFuel = RunFractionTotalFuel;
+                    }
+                } else if (RunFractionTotalFuel < OptimalSetting_RunFractionTotalFuel) {
+                    store_best_performing_mode = true;
                     OptimalSetting_RunFractionTotalFuel = RunFractionTotalFuel;
+                }
+
+                if (store_best_performing_mode) {
                     OptimalSetting = thisSetting;
                     DidWeMeetLoad = true;
                     DidWeMeetHumidification = true;
@@ -1572,8 +1597,19 @@ namespace HybridEvapCoolingModel {
                             PreviousMaxiumConditioningOutput = SensibleRoomORZone;
                         }
                     }
+
                     if (store_best_attempt) {
-                        OptimalSetting_RunFractionTotalFuel = RunFractionTotalFuel;
+                        if (ObjectiveFunction == ObjectiveFunctionType::SupplyTemperature) {
+                            if (CoolingRequested || HeatingRequested) {
+                                OptimalSetting_RunFractionSupplyTemperature = RunFractionSupplyTemperature;
+                            }
+                            // fall back to ElectricityUse since ventilation-only is just fan operation
+                            if (!CoolingRequested && !HeatingRequested && VentilationRequested) {
+                                OptimalSetting_RunFractionTotalFuel = RunFractionTotalFuel;
+                            }
+                        } else {
+                            OptimalSetting_RunFractionTotalFuel = RunFractionTotalFuel;
+                        }
                         OptimalSetting = thisSetting;
                         DidWePartlyMeetLoad = true;
                     }

src/EnergyPlus/HybridEvapCoolingModel.hh

@@ -98,11 +98,12 @@ namespace HybridEvapCoolingModel {
         SecondFuelUse,
         ThirdFuelUse,
         WaterUse,
+        SupplyTemperature,
         Num
     };
 
     constexpr std::array<std::string_view, (int)ObjectiveFunctionType::Num> objectiveFunctionNamesUC = {
-        "ELECTRICITY USE", "SECOND FUEL USE", "THIRD FUEL USE", "WATER USE"};
+        "ELECTRICITY USE", "SECOND FUEL USE", "THIRD FUEL USE", "WATER USE", "SUPPLY TEMPERATURE"};
 
     class CModeSolutionSpace
     {
@@ -261,7 +262,7 @@ namespace HybridEvapCoolingModel {
         Constant::eFuel firstFuel = Constant::eFuel::Invalid;                            // First fuel type, currently electricity is only option
         Constant::eFuel secondFuel = Constant::eFuel::Invalid;                           // Second fuel type
         Constant::eFuel thirdFuel = Constant::eFuel::Invalid;                            // Third fuel type
-        ObjectiveFunctionType ObjectiveFunction = ObjectiveFunctionType::ElectricityUse; // Objective function to minimize
+        ObjectiveFunctionType ObjectiveFunction = ObjectiveFunctionType::ElectricityUse; // Objective function to optimize
 
         int UnitOn;                          // feels like it should be a bool but its an output and I couldn't get it to work as a bool
         Real64 UnitTotalCoolingRate;         // unit output to zone, total cooling rate [W]

testfiles/UnitaryHybridAC_DedicatedOutsideAir.idf

@@ -631,7 +631,7 @@
     Electricity,             !- First Fuel Type
     NaturalGas,              !- Second Fuel Type
     DistrictCooling,         !- Third Fuel Type
-    ,                        !- Objective Function to Minimize
+    ,                        !- Objective Function to Optimize
     SZ DSOA SPACE2-1,        !- Design Specification Outdoor Air Object Name
     Mode0 Standby,           !- Mode 0 Name
     ,                        !- Mode 0 Supply Air Temperature Lookup Table Name

tst/EnergyPlus/unit/Resources/UnitaryHybridUnitTest_DOSA.idf

@@ -636,7 +636,7 @@
     Electricity,             !- First Fuel Type
     NaturalGas,              !- Second Fuel Type
     DistrictCooling,         !- Third Fuel Type
-    ,                        !- Objective Function to Minimize
+    ,                        !- Objective Function to Optimize
     SZ DSOA SPACE2-1,        !- Design Specification Outdoor Air Object Name
     Mode0 Standby,           !- Mode 0 Name
     ,                        !- Mode 0 Supply Air Temperature Lookup Table Name