New Features for Liquid-cooled Data Centers

idd/Energy+.idd.in

@@ -23123,6 +23123,135 @@ ElectricEquipment:ITE:AirCooled,
        \type object-list
        \object-list ScheduleNames
 
+ElectricEquipment:ITE:LiquidCooled,
+       \memo Represents liquid-cooled data center IT equipment racks.
+       \memo Calculates power consumption and rejects heat to ITE cooling coils.
+       \min-fields 14
+  A1 , \field Name
+       \required-field
+       \type alpha
+       \reference ITEAndITEListNames
+  A2 , \field Zone or Space Name
+       \note ZoneList and SpaceList names are not allowed.
+       \required-field
+       \type object-list
+       \object-list ZoneNames
+       \object-list SpaceNames
+       \note Zone or Space the IT equipment is located in.
+       \note Spillover air heat will be rejected to this space's heat balance.
+  A3 , \field Availability Schedule Name
+       \type object-list
+       \object-list ScheduleNames
+       \note Availability schedule name for this equipment. Schedule value > 0 means the equipment is on.
+       \note If this field is blank, the equipment is always available.
+  A4 , \field Compute Load Schedule Name
+       \required-field
+       \type object-list
+       \object-list ScheduleNames
+       \note Defines the transient CPU loading schedule.
+       \note This 0-1 factor multiplied by the design power input is the current CPU power.
+  N1 , \field Design Power Input
+       \required-field
+       \type real
+       \units W
+       \minimum 0
+       \ip-units W
+       \note Max power consumption of a single IT equipment rack.
+  N2 , \field Multiplier
+       \type real
+       \default 1.0
+       \minimum 1.0
+       \note Scales power and heat to represent multiple identical racks.
+  N3 , \field Design Fan Power Input Fraction
+       \type real
+       \minimum 0.0
+       \maximum 1.0
+       \default 0.0
+       \note Retained for auxiliary server fans contributing to air load.
+  A5 , \field IT Equipment Power Modifier Curve Name
+       \type object-list
+       \object-list BivariateFunctions
+       \note Modifies power based on loading (x) and zone air temperature (y).
+       \note This curve (table) should equal 1.0 at design conditions.
+       \note If this field is left blank, the curve is assumed to always equal 1.0.
+  N4 , \field Liquid Heat Capture Fraction
+       \type real
+       \minimum 0.0
+       \maximum 1.0
+       \default 0.8
+       \note The fraction of the total ITE heat generation (CPU + Fan) that is removed by the liquid cooling
+       \note loop at design conditions. The remaining fraction is transferred to the zone air.
+  A6 , \field Liquid Heat Capture Fraction Schedule Name
+       \type object-list
+       \object-list ScheduleNames
+       \note If provided, this schedule multiplies the Liquid Heat Capture Fraction field. This allows the
+       \note capture effectiveness to vary dynamically during the simulation.
+  A7 , \field Cooling Coil 1 Object Type
+       \required-field
+       \type choice
+       \key Coil:Cooling:ITE:ColdPlate
+       \key Coil:Cooling:ITE:UserDefined
+       \note The type of the first cooling component handling physical heat transfer.
+  A8 , \field Cooling Coil 1 Name
+       \required-field
+       \type object-list
+       \object-list CoilCoolingITENames
+       \note The specific name of the first cooling component handling physical heat transfer.
+  N5 , \field Cooling Coil 1 Load Fraction
+       \type real
+       \minimum 0.0
+       \maximum 1.0
+       \note A static fraction (0.0 to 1.0) of the total IT liquid load directed to this coil.
+       \note If this field is used, the Schedule Name field below should be left blank.
+  A9 , \field Cooling Coil 1 Load Fraction Schedule Name
+       \type object-list
+       \object-list ScheduleNames
+       \note Schedule (0.0 to 1.0) defining the fraction of the total IT liquid load directed to this coil.
+       \note If this field is used, the static Load Fraction field above should be left blank.
+  A10, \field Cooling Coil 2 Object Type
+       \type choice
+       \key Coil:Cooling:ITE:ColdPlate
+       \key Coil:Cooling:ITE:UserDefined
+       \note The type of the second cooling component, if applicable (e.g., a secondary RDHx).
+  A11, \field Cooling Coil 2 Name
+       \type object-list
+       \object-list CoilCoolingITENames
+  N6 , \field Cooling Coil 2 Load Fraction
+       \type real
+       \minimum 0.0
+       \maximum 1.0
+  A12, \field Cooling Coil 2 Load Fraction Schedule Name
+       \type object-list
+       \object-list ScheduleNames
+  A13, \field Cooling Coil 3 Object Type
+       \type choice
+       \key Coil:Cooling:ITE:ColdPlate
+       \key Coil:Cooling:ITE:UserDefined
+  A14, \field Cooling Coil 3 Name
+       \type object-list
+       \object-list CoilCoolingITENames
+  N7 , \field Cooling Coil 3 Load Fraction
+       \type real
+       \minimum 0.0
+       \maximum 1.0
+  A15, \field Cooling Coil 3 Load Fraction Schedule Name
+       \type object-list
+       \object-list ScheduleNames
+  A16, \field Cooling Coil 4 Object Type
+       \type choice
+       \key Coil:Cooling:ITE:ColdPlate
+       \key Coil:Cooling:ITE:UserDefined
+  A17, \field Cooling Coil 4 Name
+       \type object-list
+       \object-list CoilCoolingITENames
+  N8 , \field Cooling Coil 4 Load Fraction
+       \type real
+       \minimum 0.0
+       \maximum 1.0
+  A18; \field Cooling Coil 4 Load Fraction Schedule Name
+       \type object-list
+       \object-list ScheduleNames
+
 ZoneBaseboard:OutdoorTemperatureControlled,
        \memo Specifies outside temperature-controlled electric baseboard heating.
        \memo If a ZoneList, SpaceList, or a Zone comprised of more than one Space is specified

src/EnergyPlus/DataHeatBalance.hh

@@ -272,6 +272,7 @@ namespace DataHeatBalance {
         AirTerminalUserDefined,
         PackagedTESCoilTank,
         ElectricEquipmentITEAirCooled,
+        ElectricEquipmentITELiquidCooled,
         SecCoolingDXCoilSingleSpeed,
         SecHeatingDXCoilSingleSpeed,
         SecCoolingDXCoilTwoSpeed,
@@ -355,6 +356,7 @@ namespace DataHeatBalance {
         "AIRTERMINAL:SINGLEDUCT:USERDEFINED",
         "COIL:COOLING:DX:SINGLESPEED:THERMALSTORAGE",
         "ELECTRICEQUIPMENT:ITE:AIRCOOLED",
+        "ELECTRICEQUIPMENT:ITE:LIQUIDCOOLED",
         "COIL:COOLING:DX:SINGLESPEED",
         "COIL:HEATING:DX:SINGLESPEED",
         "COIL:COOLING:DX:TWOSPEED",
@@ -413,6 +415,7 @@ namespace DataHeatBalance {
         "AirTerminal:SingleDuct:UserDefined",
         "Coil:Cooling:DX:SingleSpeed:ThermalStorage",
         "ElectricEquipment:ITE:AirCooled",
+        "ElectricEquipment:ITE:LiquidCooled",
         "Coil:Cooling:DX:SingleSpeed",
         "Coil:Heating:DX:SingleSpeed",
         "Coil:Cooling:DX:TwoSpeed",
@@ -987,6 +990,29 @@ namespace DataHeatBalance {
         Num
     };
 
+    // Liquid-cooled ITE Equipment cooling coil type (Cooling Coil N Object Type field)
+    enum class ITECoolingCoilType
+    {
+        Invalid = -1,
+        ColdPlate,
+        UserDefined,
+        Num
+    };
+    static constexpr std::array<std::string_view, static_cast<int>(ITECoolingCoilType::Num)> ITECoolingCoilTypeNamesUC = {
+        "COIL:COOLING:ITE:COLDPLATE", "COIL:COOLING:ITE:USERDEFINED"};
+
+    enum class LiquidITERptVars
+    {
+        Invalid = -1,
+        CPU = 0,        // ITE CPU Electric Power/Energy
+        Fan,            // ITE Fan Electric Power/Energy
+        TotalElectric,  // ITE Total Electric Power/Energy
+        TotalHeatGen,   // ITE Total Heat Generation Power(Rate)/Energy
+        LiquidHeatGain, // ITE Liquid Heat Gain Power(Rate)/Energy
+        AirHeatGain,    // ITE Air Heat Gain to Zone Power(Rate)/Energy - convective gain
+        Num
+    };
+
     struct ITEquipData // IT Equipment
     {
         // Members
@@ -1061,6 +1087,40 @@ namespace DataHeatBalance {
         Real64 RHBelowDeltaRH = 0.0;       // ITE Air Inlet Relative Humidity Difference Below Operating Range [%]
     };
 
+    // One Cooling Coil N Object Type/Name/Load Fraction slot for ElectricEquipment:ITE:LiquidCooled
+    struct ITELiquidCoolingCoilSpec
+    {
+        ITECoolingCoilType CoilType = ITECoolingCoilType::Invalid; // Cooling Coil N Object Type
+        std::string CoilName;                                     // Cooling Coil N Name
+        Real64 LoadFraction = 0.0;                                 // Cooling Coil N Load Fraction (static)
+        Sched::Schedule *LoadFractionSched = nullptr;              // Cooling Coil N Load Fraction Schedule Name
+    };
+
+    static constexpr int MaxITELiquidCoolingCoils = 4;
+
+    struct ITEquipDataLiquidCooled // Liquid-Cooled IT Equipment
+    {
+        // Members
+        std::string Name;                     // EQUIPMENT object name
+        int ZonePtr = 0;                      // Which zone internal gain is in
+        int spaceIndex = 0;                    // Space index for this equipment instance
+        Sched::Schedule *availSched = nullptr;        // Availability schedule
+        Sched::Schedule *computeLoadSched = nullptr;  // Compute Load Schedule (0.0-1.0 CPU loading fraction)
+        Real64 DesignTotalPower = 0.0;                // Design Power Input [W]
+        Real64 Multiplier = 1.0;                      // Scales power and heat to represent multiple identical racks
+        Real64 DesignFanPowerInputFraction = 0.0;      // Fraction of design power input that is for auxiliary fans
+        int PowerModifierCurve = 0;                    // Index for power modifier function of CPU loading (x) and zone air temperature (y) curve
+        Real64 LiquidHeatCaptureFractionDesign = 0.8; // Design (nominal) fraction of total heat generation captured by the liquid loop
+        Sched::Schedule *liquidHeatCaptureFracSched = nullptr; // Optional schedule multiplying the design liquid heat capture fraction
+
+        std::array<ITELiquidCoolingCoilSpec, MaxITELiquidCoolingCoils> CoolingCoils;
+
+        // Report variables
+        std::array<Real64, (int)LiquidITERptVars::Num> PowerRpt;
+        std::array<Real64, (int)LiquidITERptVars::Num> EnergyRpt;
+        Real64 LiquidHeatCaptureFraction = 0.0; // Current effective liquid heat capture fraction []
+    };
+
     struct BBHeatData
     {
         // Members
@@ -1736,6 +1796,10 @@ namespace DataHeatBalance {
         Real64 ITEqTimeAboveRH = 0.0;          // Zone ITE Air Inlet Relative Humidity Above Operating Range Time [hr]
         Real64 ITEqTimeBelowRH = 0.0;          // Zone ITE Air Inlet Relative Humidity Below Operating Range Time [hr]
         Real64 ITEAdjReturnTemp = 0.0;         // Zone ITE Adjusted Return Air Temperature
+        // Liquid-Cooled IT Equipment
+        std::array<Real64, (int)LiquidITERptVars::Num> LiquidITEPowerRpt;
+        std::array<Real64, (int)LiquidITERptVars::Num> LiquidITEEnergyRpt;
+        Real64 LiquidITEHeatCaptureFraction = 0.0; // Zone ITE Liquid Heat Capture Fraction []
         // Overall Zone Variables
         Real64 TotRadiantGain = 0.0;
         Real64 TotVisHeatGain = 0.0;
@@ -1856,6 +1920,7 @@ struct HeatBalanceData : BaseGlobalStruct
     int TotHWEquip = 0;        // Total Hot Water Equipment instances after expansion to spaces
     int TotStmEquip = 0;       // Total Steam Equipment instances after expansion to spaces
     int TotITEquip = 0;        // Total IT Equipment instances after expansion to spaces
+    int TotITELiquidCooledEquip = 0; // Total Liquid-Cooled IT Equipment instances after expansion to spaces
     int TotInfiltration = 0;   // Total Infiltration (all types) instances after expansion to spaces
     int TotVentilation = 0;    // Total Ventilation (all types) instances after expansion to spaces
     int TotMixing = 0;         // Total Mixing Statementsn instances after expansion to spaces
@@ -2017,6 +2082,7 @@ struct HeatBalanceData : BaseGlobalStruct
     EPVector<DataHeatBalance::ZoneEquipData> ZoneHWEq;
     EPVector<DataHeatBalance::ZoneEquipData> ZoneSteamEq;
     EPVector<DataHeatBalance::ITEquipData> ZoneITEq;
+    EPVector<DataHeatBalance::ITEquipDataLiquidCooled> ZoneITELiquidCooled;
     EPVector<DataHeatBalance::BBHeatData> ZoneBBHeat;
     EPVector<DataHeatBalance::InfiltrationData> Infiltration;
     EPVector<DataHeatBalance::VentilationData> Ventilation;

src/EnergyPlus/DisplacementVentMgr.hh

@@ -78,7 +78,7 @@ namespace RoomAir {
 
     void CalcDispVent3Node(EnergyPlusData &state, int ZoneNum); // Which Zonenum
 
-    static constexpr std::array<DataHeatBalance::IntGainType, 52> IntGainTypesOccupied = {
+    static constexpr std::array<DataHeatBalance::IntGainType, 53> IntGainTypesOccupied = {
         DataHeatBalance::IntGainType::People,
         DataHeatBalance::IntGainType::WaterHeaterMixed,
         DataHeatBalance::IntGainType::WaterHeaterStratified,
@@ -87,6 +87,7 @@ namespace RoomAir {
         DataHeatBalance::IntGainType::ThermalStorageHotWaterStratified,
         DataHeatBalance::IntGainType::ElectricEquipment,
         DataHeatBalance::IntGainType::ElectricEquipmentITEAirCooled,
+        DataHeatBalance::IntGainType::ElectricEquipmentITELiquidCooled,
         DataHeatBalance::IntGainType::GasEquipment,
         DataHeatBalance::IntGainType::HotWaterEquipment,
         DataHeatBalance::IntGainType::SteamEquipment,