modelCoolingCoilHumidifyingHeating_OpenLoop

Model of a air handling unit that tests variable mass flow rates
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Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Applications.DataCenters.ChillerCooled.Equipment.Validation.BaseClasses.PartialAirHandlerMassFlow (Partial model for testing air handler at variable mass flowrate).

Information

This model demonstrates the use of Buildings.Applications.DataCenters.ChillerCooled.Equipment.CoolingCoilHumidifyingHeating for different inlet conditions.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.MassFlowRatem1_flow_nominal (from PartialAirHandlerMassFlow)2.9Nominal mass flow rate
Modelica.Units.SI.MassFlowRatem2_flow_nominal (from PartialAirHandlerMassFlow)3.3Nominal mass flow rate
Modelica.Units.SI.TemperatureT_a1_nominal (from PartialAirHandlerMassFlow)6 + 273.15Nominal water inlet temperature
Modelica.Units.SI.TemperatureT_b1_nominal (from PartialAirHandlerMassFlow)11 + 273.15Nominal water outlet temperature
Modelica.Units.SI.TemperatureT_a2_nominal (from PartialAirHandlerMassFlow)26 + 273.15Nominal air inlet temperature
Modelica.Units.SI.TemperatureT_b2_nominal (from PartialAirHandlerMassFlow)12 + 273.15Nominal air outlet temperature
Modelica.Units.SI.ThermalConductanceUA_nominalm2_flow_nominal*1006*(12 - 26)/Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(T_a1_nominal, T_b1_nominal, T_a2_nominal, T_b2_nominal)Thermal conductance at nominal flow for sensible heat, used to compute time constant
RealyValMin0.4Minimum position of water-side valves

Components

TypeNameDefaultDescription
Buildings.Fluid.Sources.Boundary_pTsin_2 (from PartialAirHandlerMassFlow)Sink for air
Buildings.Fluid.Sources.Boundary_pTsou_2 (from PartialAirHandlerMassFlow)Source for air
Buildings.Fluid.Sources.MassFlowSource_Tsin_1 (from PartialAirHandlerMassFlow)Source for water
Buildings.Fluid.Sources.Boundary_pTsou_1 (from PartialAirHandlerMassFlow)Sink for water
Modelica.Blocks.Sources.ConstantrelHum (from PartialAirHandlerMassFlow)Relative humidity
Buildings.Utilities.Psychrometrics.X_pTphix_pTphi (from PartialAirHandlerMassFlow)
Modelica.Blocks.Sources.ConstanttemSou_2 (from PartialAirHandlerMassFlow)Temperature boundary condition
Modelica.Blocks.Math.GainmWat_flow (from PartialAirHandlerMassFlow)Water mass flow rate
Modelica.Blocks.Sources.TimeTablemWatGai (from PartialAirHandlerMassFlow)Gain for water mass flow rate
Buildings.Fluid.Sensors.TemperatureTwoPorttemSenWat1 (from PartialAirHandlerMassFlow)Temperature sensor for water
Buildings.Fluid.Sensors.TemperatureTwoPorttemSenWat2 (from PartialAirHandlerMassFlow)Temperature sensor for water
Buildings.Fluid.Sensors.TemperatureTwoPorttemSenAir2 (from PartialAirHandlerMassFlow)Temperature for air
Buildings.Applications.DataCenters.ChillerCooled.Equipment.CoolingCoilHumidifyingHeatingahuAir handling unit
Buildings.Fluid.Sensors.RelativeHumidityTwoPortsenRelHumSensor for relative humidity
Modelica.Blocks.Sources.ConstantuValControl signal for water valve
Modelica.Blocks.Sources.ConstanttemSetTemperature setpoint
Modelica.Blocks.Sources.ConstantXSetMass fraction set point
Modelica.Blocks.Sources.ConstantuFanControl input for fan

Revisions

  • May 13, 2021, by Michael Wetter:
    Set start value of valve to avoid unreasonably large pressure drop due to prescribed mass flow rate that was forced through a closed valve.
    This is for #2488.
  • April 11, 2017, by Yangyang Fu:
    First implementation.