Buildings.Examples.DualFanDualDuct.ThermalZones

Information

Package Content

Name	Description
SupplyBranch	Supply branch of a dual duct system

Buildings.Examples.DualFanDualDuct.ThermalZones.SupplyBranch

Parameters

Type	Name	Default	Description
replaceable package MediumA		Modelica.Media.Interfaces.Pa...	Medium model for air
Dynamics	energyDynamicsJunctions	Modelica.Fluid.Types.Dynamic...	Formulation of energy balance in junction volumes
Boolean	dynamicBalanceJunction	true	Set to true to use a dynamic balance for junction volumes, which often leads to smaller systems of equations
Boolean	from_dp	false	= true, use m_flow = f(dp) else dp = f(m_flow)
Boolean	linearizeFlowResistance	false	= true, use linear relation between m_flow and dp for any flow rate
MassFlowRate	m_flow_nominal		Mass flow rate cold air deck [kg/s]
MassFlowRate	mAirHot_flow_nominal	0.3*m_flow_nominal	Mass flow rate hot air deck [kg/s]
MassFlowRate	mAirCol_flow_nominal	m_flow_nominal	Mass flow rate cold air deck [kg/s]
Volume	VRoo		Room volume [m3]

Connectors

Type	Name	Description
replaceable package MediumA		Medium model for air
FluidPort_a	port_aHot	Connector for hot deck
FluidPort_a	port_aCol	Connector for cold deck
FluidPort_a	port_b	Fluid connector b (positive design flow direction is from port_a1 to port_b1)
ControlBus	controlBus
input RealInput	TRoo	Measured room temperature
output RealOutput	p_relCol	Pressure signal of cold deck
output RealOutput	p_relHot	Pressure signal of hot deck

Modelica definition

model SupplyBranch "Supply branch of a dual duct system"
  replaceable package MediumA = Modelica.Media.Interfaces.PartialMedium 
    "Medium model for air";
  Modelica.Fluid.Interfaces.FluidPort_a port_aHot(redeclare package Medium =
        MediumA) "Connector for hot deck";
  Modelica.Fluid.Interfaces.FluidPort_a port_aCol(redeclare package Medium =
        MediumA) "Connector for cold deck";
  Modelica.Fluid.Interfaces.FluidPort_a port_b(redeclare package Medium =
        MediumA) 
    "Fluid connector b (positive design flow direction is from port_a1 to port_b1)";
  parameter Modelica.Fluid.Types.Dynamics energyDynamicsJunctions=Modelica.Fluid.Types.Dynamics.FixedInitial 
    "Formulation of energy balance in junction volumes";
  parameter Boolean dynamicBalanceJunction=true 
    "Set to true to use a dynamic balance for junction volumes, which often leads to smaller systems of equations";
  parameter Boolean from_dp=false 
    "= true, use m_flow = f(dp) else dp = f(m_flow)";
  parameter Boolean linearizeFlowResistance=false 
    "= true, use linear relation between m_flow and dp for any flow rate";

  parameter Modelica.SIunits.MassFlowRate m_flow_nominal 
    "Mass flow rate cold air deck";
  parameter Modelica.SIunits.MassFlowRate mAirHot_flow_nominal = 0.3*m_flow_nominal 
    "Mass flow rate hot air deck";
  parameter Modelica.SIunits.MassFlowRate mAirCol_flow_nominal = m_flow_nominal 
    "Mass flow rate cold air deck";

  parameter Modelica.SIunits.Volume VRoo "Room volume";
  Controls.RoomMixingBox con(m_flow_min=VRoo*3*1.2/3600) 
    "Room temperature controller";
  VAVReheat.Controls.ControlBus controlBus;
  Buildings.Fluid.Actuators.Dampers.VAVBoxExponential vavHot(
    redeclare package Medium = MediumA,
    A=0.6,
    use_v_nominal=true,
    m_flow_nominal=mAirHot_flow_nominal,
    dp_nominal(displayUnit="Pa") = 40,
    from_dp=from_dp,
    linearized=linearizeFlowResistance) "VAV damper for hot deck";
  Buildings.Fluid.Actuators.Dampers.VAVBoxExponential vavCol(
    redeclare package Medium = MediumA,
    A=0.6,
    use_v_nominal=true,
    m_flow_nominal=mAirCol_flow_nominal,
    dp_nominal(displayUnit="Pa") = 40,
    from_dp=from_dp,
    linearized=linearizeFlowResistance) "VAV damper for cold deck";

  Buildings.Fluid.Sensors.MassFlowRate senMasFlo(redeclare package Medium =
        MediumA) "Sensor for mass flow rate";
  Modelica.Blocks.Math.Gain fraMasFlo(k=1/m_flow_nominal) 
    "Fraction of mass flow rate, relative to nominal flow";
  Modelica.Blocks.Math.Gain ACH(k=1/VRoo/1.2*3600) "Air change per hour";
  Modelica.Blocks.Interfaces.RealInput TRoo "Measured room temperature";
  Fluid.FixedResistances.SplitterFixedResistanceDpM mix(
    redeclare package Medium = MediumA,
    m_flow_nominal={mAirCol_flow_nominal,mAirHot_flow_nominal,mAirCol_flow_nominal +
        mAirHot_flow_nominal},
    energyDynamics=energyDynamicsJunctions,
    massDynamics=energyDynamicsJunctions,
    from_dp=from_dp,
    linearized=linearizeFlowResistance,
    dynamicBalance=false,
    dp_nominal=20*{0,0,0}) "Mixer for hot and cold air deck";

  Fluid.Sensors.RelativePressure senRelPreHot(redeclare package Medium =
        MediumA) "Relative pressure hot deck (compared to room pressure)";
  Fluid.Sensors.RelativePressure senRelPreCol(redeclare package Medium =
        MediumA) "Relative pressure cold deck (compared to room pressure)";
  Modelica.Blocks.Interfaces.RealOutput p_relCol "Pressure signal of cold deck";
  Modelica.Blocks.Interfaces.RealOutput p_relHot "Pressure signal of hot deck";
  Fluid.Sensors.TemperatureTwoPort TSup(redeclare package Medium = MediumA,
      m_flow_nominal=m_flow_nominal) "Supply air temperature";
equation 
  connect(fraMasFlo.u, senMasFlo.m_flow);
  connect(ACH.u, senMasFlo.m_flow);
  connect(con.TRoo, TRoo);
  connect(vavHot.port_a, port_aHot);
  connect(vavHot.port_b, mix.port_2);
  connect(mix.port_1, vavCol.port_b);
  connect(mix.port_3, senMasFlo.port_a);
  connect(senMasFlo.m_flow, con.mAir_flow);
  connect(con.yHot, vavHot.y);
  connect(con.yCol, vavCol.y);
  connect(senRelPreHot.port_a, port_aHot);
  connect(senRelPreCol.port_a, port_aCol);
  connect(vavCol.port_a, port_aCol);
  connect(senRelPreHot.port_b, mix.port_3);
  connect(senRelPreCol.port_b, mix.port_3);
  connect(senRelPreCol.p_rel, p_relCol);
  connect(senRelPreHot.p_rel, p_relHot);
  connect(con.TRooSetHea, controlBus.TRooSetHea);
  connect(con.TRooSetCoo, controlBus.TRooSetCoo);
  connect(senMasFlo.port_b, TSup.port_a);
  connect(TSup.port_b, port_b);
end SupplyBranch;