LBL logo

Buildings.Fluid.HeatExchangers.Examples.BaseClasses

Package with base classes for Buildings.Fluid.HeatExchangers.Examples

Information

This package contains base classes that are used to construct the models in Buildings.Fluid.HeatExchangers.Examples.

Extends from Modelica.Icons.BasesPackage (Icon for packages containing base classes).

Package Content

NameDescription
EffectivenessNTUMassFlow Partial model of epsilon-NTU coil that tests variable mass flow rates


Buildings.Fluid.HeatExchangers.Examples.BaseClasses.EffectivenessNTUMassFlow

Partial model of epsilon-NTU coil that tests variable mass flow rates

Buildings.Fluid.HeatExchangers.Examples.BaseClasses.EffectivenessNTUMassFlow

Parameters

TypeNameDefaultDescription
TemperatureT_a1_nominal5 + 273.15[K]
TemperatureT_b1_nominal10 + 273.15[K]
TemperatureT_a2_nominal30 + 273.15[K]
TemperatureT_b2_nominal15 + 273.15[K]
HeatFlowRateQ_flow_nominalm1_flow_nominal*4200*(T_a1_n...Nominal heat transfer [W]
MassFlowRatem1_flow_nominal0.1Nominal mass flow rate medium 1 [kg/s]
MassFlowRatem2_flow_nominalm1_flow_nominal*4200/1000*(T...Nominal mass flow rate medium 2 [kg/s]

Modelica definition

partial model EffectivenessNTUMassFlow 
  "Partial model of epsilon-NTU coil that tests variable mass flow rates"
  import Buildings;
  package Medium1 = Buildings.Media.ConstantPropertyLiquidWater;
  package Medium2 = Buildings.Media.PerfectGases.MoistAirUnsaturated;
  parameter Modelica.SIunits.Temperature T_a1_nominal=5 + 273.15;
  parameter Modelica.SIunits.Temperature T_b1_nominal=10 + 273.15;
  parameter Modelica.SIunits.Temperature T_a2_nominal=30 + 273.15;
  parameter Modelica.SIunits.Temperature T_b2_nominal=15 + 273.15;
  parameter Modelica.SIunits.HeatFlowRate Q_flow_nominal = m1_flow_nominal*4200*(T_a1_nominal-T_b1_nominal) 
    "Nominal heat transfer";
  parameter Modelica.SIunits.MassFlowRate m1_flow_nominal=0.1 
    "Nominal mass flow rate medium 1";
  parameter Modelica.SIunits.MassFlowRate m2_flow_nominal=m1_flow_nominal*4200/
      1000*(T_a1_nominal - T_b1_nominal)/(T_b2_nominal - T_a2_nominal) 
    "Nominal mass flow rate medium 2";
  Buildings.Fluid.Sources.Boundary_pT sin_2(
    redeclare package Medium = Medium2,
    use_p_in=false,
    p(displayUnit="Pa") = 101325,
    T=T_a2_nominal);
  Buildings.Fluid.Sources.MassFlowSource_T sou_2(
    redeclare package Medium = Medium2,
    T=T_a2_nominal,
    X={0.02,1 - 0.02},
    use_T_in=true,
    use_X_in=true,
    m_flow=m2_flow_nominal,
    use_m_flow_in=true);
  Buildings.Fluid.Sources.Boundary_pT sin_1(
    redeclare package Medium = Medium1,
    use_p_in=false,
    p=300000,
    T=T_a1_nominal);
  Buildings.Fluid.Sources.MassFlowSource_T sou_1(
    redeclare package Medium = Medium1,
    use_m_flow_in=true,
    use_T_in=false,
    T=T_a1_nominal);

  inner Modelica.Fluid.System system;
  Modelica.Blocks.Sources.Constant const(k=0.8);
  Buildings.Utilities.Psychrometrics.X_pTphi x_pTphi(use_p_in=false, redeclare 
      package Medium = Medium2);
  Modelica.Blocks.Sources.Constant const1(k=T_a2_nominal);
  Modelica.Blocks.Math.Gain mWat_flow(k=m1_flow_nominal) "Water mass flow rate";
  Modelica.Blocks.Sources.TimeTable mWatGai(
    table=[0,1; 3600*0.1,1; 3600*0.2,0.01; 3600*0.3,0.01]) 
    "Gain for water mass flow rate";
  Modelica.Blocks.Sources.TimeTable mAirGai(
    table=[0,1; 3600*0.5,1; 3600*0.6,-1; 3600*0.7,0; 3600*1,0]) 
    "Gain for air mass flow rate";
  Modelica.Blocks.Math.Gain mAir_flow(k=m2_flow_nominal) "Air mass flow rate";
equation 
  connect(x_pTphi.X, sou_2.X_in);
  connect(const.y, x_pTphi.phi);
  connect(const1.y, x_pTphi.T);
  connect(const1.y, sou_2.T_in);
  connect(mWat_flow.y, sou_1.m_flow_in);
  connect(mAir_flow.y, sou_2.m_flow_in);
  connect(mAirGai.y, mAir_flow.u);
  connect(mWatGai.y, mWat_flow.u);
end EffectivenessNTUMassFlow;

Automatically generated Wed Feb 22 15:22:24 2012.