ÂJulien,
Availability managers in plant or air loop will turn on or off the entire loop (not individual dry or evaporative fluid coolers) so they may not serve the purpose in this case. If the dry and evaporative fluid coolers are in parallel branches with their branch pumps, these pumps' schedule can be modified using EMS. (Something like below). You can try and see if this works.Another lot more time consuming but accurate way could be to use PlantComponent:UserDefined. This object will allow to define the behavior of hybrid cooling tower. Branch,  Condenser Supply Fluidcooler Branch 1,  !- Name  0,            !- Maximum Flow Rate {m3/s}  ,             !- Pressure Drop Curve Name  Pump:VariableSpeed,    !- Component 1 Object Type  Cond Circ Pump 1,      !- Component 1 Name  Cond Circ Pump 1 Inlet Node,  !- Component 1 Inlet Node Name  Condenser Fluidcooler Inlet Node,  !- Component 1 Outlet Node Name  ACTIVE,          !- Component 1 Branch Control Type  Fluidcooler:SingleSpeed, !- Component 2 Object Type  Big FluidCooler,     !- Component 2 Name  Condenser Fluidcooler Inlet Node,  !- Component 2 Inlet Node Name  Condenser Fluidcooler Outlet Node,  !- Component 2 Outlet Node Name  ACTIVE;          !- Component 2 Branch Control Type Branch,  Condenser Supply Fluidcooler Branch 2,  !- Name  0,            !- Maximum Flow Rate {m3/s}  ,             !- Pressure Drop Curve Name  Pump:VariableSpeed,    !- Component 1 Object Type  Cond Circ Pump 2,      !- Component 1 Name  Cond Circ Pump 2 Inlet Node,  !- Component 1 Inlet Node Name  Condenser EvapFluidcooler Inlet Node,  !- Component 1 Outlet Node Name  ACTIVE,          !- Component 1 Branch Control Type  EvaporativeFluidCooler:SingleSpeed, !- Component 2 Object Type  Big EvaporativeFluidCooler,     !- Component 2 Name  Condenser EvapFluidcooler Inlet Node,  !- Component 2 Inlet Node Name  Condenser EvapFluidcooler Outlet Node,  !- Component 2 Outlet Node Name  ACTIVE;          !- Component 2 Branch Control Type Pump:VariableSpeed,  Cond Circ Pump 1,      !- Name  Cond Circ Pump 1 Inlet Node,  !- Inlet Node Name  Condenser Fluidcooler Inlet Node,  !- Outlet Node Name  0.001388,         !- Rated Flow Rate {m3/s}  297500,          !- Rated Pump Head {Pa}  500,           !- Rated Power Consumption {W}  .87,           !- Motor Efficiency  0.0,           !- Fraction of Motor Inefficiencies to Fluid Stream  0,            !- Coefficient 1 of the Part Load Performance Curve  1,            !- Coefficient 2 of the Part Load Performance Curve  0,            !- Coefficient 3 of the Part Load Performance Curve  0,            !- Coefficient 4 of the Part Load Performance Curve  0,            !- Minimum Flow Rate {m3/s}  INTERMITTENT,       !- Pump Control Type  CondCircPump1PumpAvailSched;  !- Pump Flow Rate Schedule Name Fluidcooler:SingleSpeed,  Big FluidCooler,     !- Name  Condenser Fluidcooler Inlet Node,  !- Water Inlet Node Name  Condenser Fluidcooler Outlet Node,  !- Water Outlet Node Name  NominalCapacity,     !- Performance Input Method  ,             !- Design Air Flow Rate U-factor Times Area Value {W/K}  58601.,          !- Nominal Capacity {W}  51.67,          !- Design Entering Water Temperature {C}  35,            !- Design Entering Air Temperature {C}  25.6,           !- Design Entering Air Wetbulb Temperature {C}  0.001388,         !- Design Water Flow Rate {m3/s}  9.911,          !- Design Air Flow Rate {m3/s}  autosize;         !- Design Air Flow Rate Fan Power {W} Pump:VariableSpeed,  Cond Circ Pump 2,      !- Name  Cond Circ Pump 2 Inlet Node,  !- Inlet Node Name  Condenser EvapFluidcooler Inlet Node,  !- Outlet Node Name  0.001388,         !- Rated Flow Rate {m3/s}  297500,          !- Rated Pump Head {Pa}  500,           !- Rated Power Consumption {W}  .87,           !- Motor Efficiency  0.0,           !- Fraction of Motor Inefficiencies to Fluid Stream  0,            !- Coefficient 1 of the Part Load Performance Curve  1,            !- Coefficient 2 of the Part Load Performance Curve  0,            !- Coefficient 3 of the Part Load Performance Curve  0,            !- Coefficient 4 of the Part Load Performance Curve  0,            !- Minimum Flow Rate {m3/s}  INTERMITTENT,       !- Pump Control Type  CondCircPump2PumpAvailSched;  !- Pump Flow Rate Schedule Name EvaporativeFluidcooler:SingleSpeed,  Big EvaporativeFluidCooler,  !- Name  Condenser EvapFluidcooler Inlet Node,  !- Water Inlet Node Name  Condenser EvapFluidcooler Outlet Node,  !- Water Outlet Node Name  3.02,           !- Design Air Flow Rate {m3/s}  2250,           !- Design Air Flow Rate Fan Power {W}  0.002208,         !- Design Spray Water Flow Rate {m3/s}  UserSpecifiedDesignCapacity,  !- Performance Input Method  ,             !- Outdoor Air Inlet Node Name  ,             !- Heat Rejection Capacity and Nominal Capacity Sizing Ratio  ,             !- Standard Design Capacity {W}  ,             !- Design Air Flow Rate U-factor Times Area Value {W/K}  0.001703,         !- Design Water Flow Rate {m3/s}  87921,          !- User Specified Design Capacity {W}  46.11,          !- Design Entering Water Temperature {C}  35,            !- Design Entering Air Temperature {C}  25.6;           !- Design Entering Air Wet-bulb Temperature {C} Schedule:Compact,  CondCircPump1PumpAvailSched,  !- Name  Fraction,         !- Schedule Type Limits Name  Through: 12/31,      !- Field 1  For: AllDays,       !- Field 2  Until: 24:00,0.0;     !- Field 3 Schedule:Compact,  CondCircPump2PumpAvailSched,  !- Name  Fraction,         !- Schedule Type Limits Name  Through: 12/31,      !- Field 1  For: AllDays,       !- Field 2  Until: 24:00,0.0;     !- Field 3 EnergyManagementSystem:Actuator,  Set_CondCircPump1Avail_Sched, !- Name  CondCircPump1PumpAvailSched, !- Actuated Component Unique Name  Schedule:Compact,       !- Actuated Component Type  Schedule Value;        !- Actuated Component Control Type
 EnergyManagementSystem:Actuator,  Set_CondCircPump2Avail_Sched, !- Name  CondCircPump2PumpAvailSched, !- Actuated Component Unique Name  Schedule:Compact,       !- Actuated Component Type  Schedule Value;        !- Actuated Component Control Type
 EnergyManagementSystem:ProgramCallingManager,  My Setpoint Schedule Calculator Example,  BeginTimestepBeforePredictor,  Set_CondCircPumpAvail_Sched_Prog; EnergyManagementSystem:Sensor,  OutdoorTemp,              !- Name  Environment,              !- Output:Variable Index Key Name  Site Outdoor Air Drybulb Temperature;  !- Output:Variable Name EnergyManagementSystem:Program,Set_CondCircPumpAvail_Sched_Prog,IF (OutdoorTemp <= 18.33 && OutdoorTemp > 0.0), Set Set_CondCircPump1Avail_Sched = 1.0 , Set Set_CondCircPump2Avail_Sched = 0.0 ,ELSEIF (OutdoorTemp > 21.0), Set Set_CondCircPump1Avail_Sched = 0.0 , Set Set_CondCircPump2Avail_Sched = 1.0 ,ENDIF; Output:Variable,CondCircPump1PumpAvailSched,Schedule Value,timestep; Output:Variable,CondCircPump2PumpAvailSched,Schedule Value,timestep; Output:Variable,Cond Circ Pump 1,Pump Electric Power,timestep; Output:Variable,Cond Circ Pump 1,Pump Mass Flow Rate,timestep; Output:Variable,Cond Circ Pump 2,Pump Electric Power,timestep; Output:Variable,Cond Circ Pump 2,Pump Mass Flow Rate,timestep;On Fri, Aug 1, 2014 at 10:17 PM, Julien Marrec julien.marrec@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
ÂHi,Has anyone successfully modeled an hybrid cooling tower in E+?By hybrid I mean running dry until a switchover temperature. When the outdoor dry bulb is above, say, 65°F, you start spraying.
How would you do it?Should I use for example one CoolingTower:TwoSpeed and one FluidCooler:TwoSpeed and turn them on/off based on outdoor temperature using an availabilitymanager?
Thanks for any insight you can provide.Best,
Julien--LinkedIn (en) : www.linkedin.com/in/julienmarrec
Julien Marrec, EBCP, BPI MFBA
Energy&Sustainability Engineer
T: +33 6 95 14 42 13
www.julienmarrec.com
DoYouBuzz : www.doyoubuzz.com/julien-marrec_1
LinkedIn (fr) : www.linkedin.com/in/julienmarrec/fr
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