Buildings.HeatExchangers

Package with heat exchanger models

Package Content

Name Description

BaseClasses Package with base classes for heat exchanger models

ConstantEffectiveness Heat exchanger with constant effectiveness

CoolingTowers Package with cooling tower models

Examples Collection of models that illustrate model use and test models

HeaterCoolerIdeal Ideal electric heater or cooler, no losses, no dynamics

SensibleCoilDiscretized Heat exchanger with discretization along the flow path

SensibleHexHAInput Simple heat exchanger with convective heat transfer as input

Name	Description
BaseClasses	Package with base classes for heat exchanger models
ConstantEffectiveness	Heat exchanger with constant effectiveness
CoolingTowers	Package with cooling tower models
Examples	Collection of models that illustrate model use and test models
HeaterCoolerIdeal	Ideal electric heater or cooler, no losses, no dynamics
SensibleCoilDiscretized	Heat exchanger with discretization along the flow path
SensibleHexHAInput	Simple heat exchanger with convective heat transfer as input

Buildings.HeatExchangers.ConstantEffectiveness

Heat exchanger with constant effectiveness

Buildings.HeatExchangers.ConstantEffectiveness

Information

Model for a heat exchanger with constant effectiveness.

This model transfers heat in the amount of

  Q = Q_max * eps,

where eps is a constant effectiveness and Q_max is the maximum heat that can be transferred.

Parameters

Type	Name	Default	Description
Boolean	allowFlowReversal_1	flowDirection_1 == Modelica_...	= false, if flow only from port_a to port_b, otherwise reversing flow allowed
Boolean	allowFlowReversal_2	flowDirection_2 == Modelica_...	= false, if flow only from port_a to port_b, otherwise reversing flow allowed
Real	eps	0.8	Heat exchanger effectiveness
Fluid 1
replaceable package Medium_1	PartialMedium	Fluid 1
Fluid 2
replaceable package Medium_2	PartialMedium	Fluid 2
Initialization
MassFlowRate	m_flow_1		Mass flow rate from port_a1 to port_b1 (m_flow_1 > 0 is design flow direction) [kg/s]
MassFlowRate	m_flow_2		Mass flow rate from port_a2 to port_b2 (m_flow_2 > 0 is design flow direction) [kg/s]
Pressure	dp_1		Pressure difference between port_a1 and port_b1 [Pa]
Pressure	dp_2		Pressure difference between port_a2 and port_b2 [Pa]
Advanced
Temp	flowDirection_1	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component
Temp	flowDirection_2	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component

Connectors

Type Name Description

FluidPort_a port_a1 Fluid connector a for medium 1 (positive design flow direction is from port_a1 to port_b1)

FluidPort_b port_b1 Fluid connector b for medium 1 (positive design flow direction is from port_a to port_b)

FluidPort_a port_a2 Fluid connector a for medium 2 (positive design flow direction is from port_a2 to port_b2)

FluidPort_b port_b2 Fluid connector b for medium 2 (positive design flow direction is from port_a to port_b)

Type	Name	Description
FluidPort_a	port_a1	Fluid connector a for medium 1 (positive design flow direction is from port_a1 to port_b1)
FluidPort_b	port_b1	Fluid connector b for medium 1 (positive design flow direction is from port_a to port_b)
FluidPort_a	port_a2	Fluid connector a for medium 2 (positive design flow direction is from port_a2 to port_b2)
FluidPort_b	port_b2	Fluid connector b for medium 2 (positive design flow direction is from port_a to port_b)

Modelica definition

model ConstantEffectiveness 
  "Heat exchanger with constant effectiveness" 
  extends Fluids.Interfaces.PartialStaticFourPortHeatMassTransfer;
  extends Buildings.BaseClasses.BaseIcon;
  parameter Real eps(min=0, max=1) = 0.8 "Heat exchanger effectiveness";
  
  Modelica.SIunits.Temperature T_in1 "Inlet temperature medium 1";
  Modelica.SIunits.Temperature T_in2 "Inlet temperature medium 2";
  Modelica.SIunits.ThermalConductance C_flow_1 
    "Heat capacity flow rate medium 1";
  Modelica.SIunits.ThermalConductance C_flow_2 
    "Heat capacity flow rate medium 2";
  Modelica.SIunits.ThermalConductance CMin_flow(min=0) 
    "Minimum heat capacity flow rate";
  Modelica.SIunits.HeatFlowRate QMax_flow "Maximum heat flow rate";
  
equation 
  // definitions for heat transfer effectiveness model
  T_in1 = if m_flow_1 >= 0 then medium_a1.T else medium_b1.T;
  T_in2 = if m_flow_2 >= 0 then medium_a2.T else medium_b2.T;
  C_flow_1 = abs(m_flow_1)
          * Medium_1.specificHeatCapacityCp(Medium_1.setState_pTX(medium_a1.p,
                medium_a1.T, medium_a1.X));
  C_flow_2 = abs(m_flow_2)
          * Medium_2.specificHeatCapacityCp(Medium_2.setState_pTX(medium_a2.p,
                medium_a2.T, medium_a2.X));
  
  CMin_flow = min( C_flow_1, C_flow_2);
  QMax_flow = CMin_flow * (T_in2 - T_in1);
  
  // transferred heat
  Q_flow_1 = eps * QMax_flow;
  0 = Q_flow_1 + Q_flow_2;
  
  // no mass exchange
  mXi_flow_1 = zeros(Medium_1.nXi);
  mXi_flow_2 = zeros(Medium_2.nXi);
  
  // no pressure drop
  dp_1 = 0;
  dp_2 = 0;
end ConstantEffectiveness;

Buildings.HeatExchangers.HeaterCoolerIdeal

Ideal electric heater or cooler, no losses, no dynamics

Buildings.HeatExchangers.HeaterCoolerIdeal

Information

Model for an electric heater or cooler.

This model adds heat in the amount of Q_flow = u Q0_flow to the medium. The input signal u and the nominal heat flow rate Q0_flow can be positive or negative.

Note that if the mass flow rate tends to zero, the temperature difference over this component tends to infinity for non-zero Q_flow, so add proper control when using this component.

Parameters

Type Name Default Description

replaceable package Medium PartialMedium Medium in the component

HeatFlowRate Q0_flow Heat flow rate at u=1, positive for heating [W]

Initialization

MassFlowRate m_flow Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s]

Pressure dp Pressure difference between port_a and port_b [Pa]

Advanced

Temp flowDirection Modelica_Fluid.Types.FlowDir... Unidirectional (port_a -> port_b) or bidirectional flow component

Type	Name	Default	Description
replaceable package Medium	PartialMedium	Medium in the component
HeatFlowRate	Q0_flow		Heat flow rate at u=1, positive for heating [W]
Initialization
MassFlowRate	m_flow		Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s]
Pressure	dp		Pressure difference between port_a and port_b [Pa]
Advanced
Temp	flowDirection	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component

Connectors

Type Name Description

FluidPort_a port_a Fluid connector a (positive design flow direction is from port_a to port_b)

FluidPort_b port_b Fluid connector b (positive design flow direction is from port_a to port_b)

input RealInput u

Type	Name	Description
FluidPort_a	port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
FluidPort_b	port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
input RealInput	u

Modelica definition

model HeaterCoolerIdeal 
  "Ideal electric heater or cooler, no losses, no dynamics" 
  extends Fluids.Interfaces.PartialStaticTwoPortHeatMassTransfer;
  extends Buildings.BaseClasses.BaseIcon;
  
  parameter Modelica.SIunits.HeatFlowRate Q0_flow 
    "Heat flow rate at u=1, positive for heating";
  Modelica.Blocks.Interfaces.RealInput u;
equation 
  dp = 0;
  Q_flow = Q0_flow * u;
  mXi_flow = zeros(Medium.nXi); // no mass added or removed (sensible heat only)
end HeaterCoolerIdeal;

Buildings.HeatExchangers.SensibleCoilDiscretized

Heat exchanger with discretization along the flow path

Buildings.HeatExchangers.SensibleCoilDiscretized

Information

Model of a discretized heat exchanger. The heat exchanger is discretized along the flow path. Each element has a state variable, modeled either using a lumped mass for the metal interface, or a fluid volume for the two flow paths.

The heat exchanger geometry is configured so that the heat exchanger has different registers. A register is a collection of parallel pipes that may be discretized along the pipe length. The pipes are perpendicular to the air flow path. When using this model, the water (or liquid) flow path needs to be connected to port_a1 and port_b1, and the air flow path need to be connected to the other two ports.

Currently, only sensible heat transfer is modeled.

Parameters

Type Name Default Description

Boolean allowFlowReversal_1 flowDirection_1 == Modelica_... = false, if flow only from port_a to port_b, otherwise reversing flow allowed

Boolean allowFlowReversal_2 flowDirection_2 == Modelica_... = false, if flow only from port_a to port_b, otherwise reversing flow allowed

Real ReC_1 4000 Reynolds number where transition to laminar starts inside pipes

Real ReC_2 4000 Reynolds number where transition to laminar starts inside ducts

Fluid 1

replaceable package Medium_1 PartialMedium Fluid 1

Fluid 2

replaceable package Medium_2 PartialMedium Fluid 2

Initialization

MassFlowRate m_flow_1 Mass flow rate from port_a1 to port_b1 (m_flow_1 > 0 is design flow direction) [kg/s]

MassFlowRate m_flow_2 Mass flow rate from port_a2 to port_b2 (m_flow_2 > 0 is design flow direction) [kg/s]

Pressure dp_1 Pressure difference between port_a1 and port_b1 [Pa]

Pressure dp_2 Pressure difference between port_a2 and port_b2 [Pa]

Nominal condition

Temperature dT0 10 Temperature difference [K]

HeatFlowRate Q0_flow 1000 Heat transfer at dT0 [W]

ThermalConductance UA0 Q0_flow/dT0 Thermal conductance at nominal flow, used to compute heat capacity [W/K]

MassFlowRate m0_flow_1 Mass flow rate at port_a1 for all pipes [kg/s]

Pressure dp0_1 Pressure drop for all pipes [Pa]

MassFlowRate m0_flow_2 Mass flow rate at port_a_2 for duct [kg/s]

Pressure dp0_2 Pressure drop inside duct [Pa]

Time tau_1 60 Time constant at nominal flow for medium 1 [s]

Time tau_2 60 Time constant at nominal flow for medium 2 [s]

Time tau_m 60 Time constant of metal at nominal UA value [s]

Geometry

Integer nReg 2 Number of registers

Integer nPipPar 3 Number of parallel pipes in each register

Integer nPipSeg 4 Number of pipe segments per register used for discretization

Length dh_1 0.025 Hydraulic diameter for a single pipe [m]

Length dh_2 1 Hydraulic diameter for duct [m]

Advanced

Temp flowDirection_1 Modelica_Fluid.Types.FlowDir... Unidirectional (port_a -> port_b) or bidirectional flow component

Temp flowDirection_2 Modelica_Fluid.Types.FlowDir... Unidirectional (port_a -> port_b) or bidirectional flow component

Heat transfer

HASensibleCoil hAModel redeclare BaseClasses.HASens... Model for convective heat transfer coefficient

Type	Name	Default	Description
Boolean	allowFlowReversal_1	flowDirection_1 == Modelica_...	= false, if flow only from port_a to port_b, otherwise reversing flow allowed
Boolean	allowFlowReversal_2	flowDirection_2 == Modelica_...	= false, if flow only from port_a to port_b, otherwise reversing flow allowed
Real	ReC_1	4000	Reynolds number where transition to laminar starts inside pipes
Real	ReC_2	4000	Reynolds number where transition to laminar starts inside ducts
Fluid 1
replaceable package Medium_1	PartialMedium	Fluid 1
Fluid 2
replaceable package Medium_2	PartialMedium	Fluid 2
Initialization
MassFlowRate	m_flow_1		Mass flow rate from port_a1 to port_b1 (m_flow_1 > 0 is design flow direction) [kg/s]
MassFlowRate	m_flow_2		Mass flow rate from port_a2 to port_b2 (m_flow_2 > 0 is design flow direction) [kg/s]
Pressure	dp_1		Pressure difference between port_a1 and port_b1 [Pa]
Pressure	dp_2		Pressure difference between port_a2 and port_b2 [Pa]
Nominal condition
Temperature	dT0	10	Temperature difference [K]
HeatFlowRate	Q0_flow	1000	Heat transfer at dT0 [W]
ThermalConductance	UA0	Q0_flow/dT0	Thermal conductance at nominal flow, used to compute heat capacity [W/K]
MassFlowRate	m0_flow_1		Mass flow rate at port_a1 for all pipes [kg/s]
Pressure	dp0_1		Pressure drop for all pipes [Pa]
MassFlowRate	m0_flow_2		Mass flow rate at port_a_2 for duct [kg/s]
Pressure	dp0_2		Pressure drop inside duct [Pa]
Time	tau_1	60	Time constant at nominal flow for medium 1 [s]
Time	tau_2	60	Time constant at nominal flow for medium 2 [s]
Time	tau_m	60	Time constant of metal at nominal UA value [s]
Geometry
Integer	nReg	2	Number of registers
Integer	nPipPar	3	Number of parallel pipes in each register
Integer	nPipSeg	4	Number of pipe segments per register used for discretization
Length	dh_1	0.025	Hydraulic diameter for a single pipe [m]
Length	dh_2	1	Hydraulic diameter for duct [m]
Advanced
Temp	flowDirection_1	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component
Temp	flowDirection_2	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component
Heat transfer
HASensibleCoil	hAModel	redeclare BaseClasses.HASens...	Model for convective heat transfer coefficient

Connectors

Type	Name	Description
FluidPort_a	port_a1	Fluid connector a for medium 1 (positive design flow direction is from port_a1 to port_b1)
FluidPort_b	port_b1	Fluid connector b for medium 1 (positive design flow direction is from port_a to port_b)
FluidPort_a	port_a2	Fluid connector a for medium 2 (positive design flow direction is from port_a2 to port_b2)
FluidPort_b	port_b2	Fluid connector b for medium 2 (positive design flow direction is from port_a to port_b)

Modelica definition

model SensibleCoilDiscretized 
  "Heat exchanger with discretization along the flow path" 
  extends Fluids.Interfaces.PartialStaticFourPortInterface;
  extends Buildings.BaseClasses.BaseIcon;
  
  
  parameter Modelica.SIunits.Temperature dT0(min=0) = 10 
    "Temperature difference";
  parameter Modelica.SIunits.HeatFlowRate Q0_flow(min=0) = 1000 
    "Heat transfer at dT0";
  parameter Modelica.SIunits.ThermalConductance UA0(min=0) = Q0_flow/dT0 
    "Thermal conductance at nominal flow, used to compute heat capacity";
  parameter Integer nReg(min=2)=2 "Number of registers";
  parameter Integer nPipPar(min=1) = 3 
    "Number of parallel pipes in each register";
  parameter Integer nPipSeg(min=1) = 4 
    "Number of pipe segments per register used for discretization";
  
  Buildings.HeatExchangers.BaseClasses.SensibleCoilRegister hexReg[
                                                                  nReg](
    redeclare each package Medium_1 = Medium_1,
    redeclare each package Medium_2 = Medium_2,
    each final nPipPar=nPipPar,
    each final nPipSeg=nPipSeg,
    each final UA0=Q0_flow/dT0/nReg,
    each final m0_flow_1=m0_flow_1/nPipPar,
    each final m0_flow_2=m0_flow_1/nPipPar/nPipSeg,
    each tau_1=tau_1,
    each tau_2=tau_2,
    each tau_m=tau_m) "Heat exchanger register";
  Buildings.HeatExchangers.BaseClasses.PipeManifoldFixedResistance pipMan_a(
    redeclare package Medium = Medium_1,
    final nPipPar=nPipPar,
    final m0_flow=m0_flow_1,
    final dp0=dp0_1,
    final dh=dh_1,
    final ReC=ReC_1) "Pipe manifold at port a";
  Buildings.HeatExchangers.BaseClasses.PipeManifoldNoResistance pipMan_b(
    redeclare package Medium = Medium_1,
    final nPipPar=nPipPar) "Pipe manifold at port b";
  Buildings.HeatExchangers.BaseClasses.DuctManifoldNoResistance ducMan_b(
    redeclare package Medium = Medium_2,
    final nPipPar=nPipPar,
    final nPipSeg=nPipSeg) "Duct manifold at port b";
  Buildings.HeatExchangers.BaseClasses.DuctManifoldFixedResistance ducMan_a(
    redeclare package Medium = Medium_2,
    final nPipPar = nPipPar,
    final nPipSeg = nPipSeg,
    final m0_flow=m0_flow_2,
    final dp0=dp0_2,
    final dh=dh_2,
    final ReC=ReC_2) "Duct manifold at port a";
public 
  parameter Modelica.SIunits.Length dh_1=0.025 
    "Hydraulic diameter for a single pipe";
  parameter Real ReC_1=4000 
    "Reynolds number where transition to laminar starts inside pipes";
  parameter Modelica.SIunits.MassFlowRate m0_flow_1 
    "Mass flow rate at port_a1 for all pipes";
  parameter Modelica.SIunits.Pressure dp0_1 "Pressure drop for all pipes";
  parameter Modelica.SIunits.Length dh_2=1 "Hydraulic diameter for duct";
  parameter Real ReC_2=4000 
    "Reynolds number where transition to laminar starts inside ducts";
  parameter Modelica.SIunits.MassFlowRate m0_flow_2 
    "Mass flow rate at port_a_2 for duct";
  parameter Modelica.SIunits.Pressure dp0_2 "Pressure drop inside duct";
  Modelica.SIunits.HeatFlowRate Q_flow_1 
    "Heat transfered from solid into medium 1";
  Modelica.SIunits.HeatFlowRate Q_flow_2 
    "Heat transfered from solid into medium 2";
  parameter Modelica.SIunits.Time tau_1=60 
    "Time constant at nominal flow for medium 1";
  parameter Modelica.SIunits.Time tau_2=60 
    "Time constant at nominal flow for medium 2";
  parameter Modelica.SIunits.Time tau_m=60 
    "Time constant of metal at nominal UA value";
  
protected 
  BaseClasses.RegisterHeader hea1[nReg/2](
      redeclare each final package Medium = Medium_1,
      each final nPipPar = nPipPar) if 
      nReg > 1 "Pipe header to redirect flow into next register";
  BaseClasses.RegisterHeader hea2[nReg/2-1](
      redeclare each final package Medium = Medium_1,
      each final nPipPar = nPipPar) if 
      nReg > 2 "Pipe header to redirect flow into next register";
  Modelica.Blocks.Math.Gain gai_1(k=1/nReg) 
    "Gain medium-side 1 to take discretization into account";
  Modelica.Blocks.Math.Gain gai_2(k=1/nReg) 
    "Gain medium-side 2 to take discretization into account";
public 
  replaceable BaseClasses.HASensibleCoil hAModel(
               UA0=UA0, m0_flow_a=m0_flow_2, m0_flow_w=m0_flow_1,
               waterSideTemperatureDependent=true,
               waterSideFlowDependent=true,
               airSideTemperatureDependent=true,
               airSideFlowDependent=true) extends BaseClasses.PartialHA 
    "Model for convective heat transfer coefficient";
protected 
  Modelica_Fluid.Sensors.Temperature temSen_1(redeclare package Medium = 
        Medium_1) "Temperature sensor";
  Modelica_Fluid.Sensors.MassFlowRate masFloSen_1(redeclare package Medium = 
        Medium_1) "Mass flow rate sensor";
  Modelica_Fluid.Sensors.Temperature temSen_2(redeclare package Medium = 
        Medium_2) "Temperature sensor";
  Modelica_Fluid.Sensors.MassFlowRate masFloSen_2(redeclare package Medium = 
        Medium_2) "Mass flow rate sensor";
equation 
  Q_flow_1 = sum(hexReg[i].Q_flow_1 for i in 1:nReg);
  Q_flow_2 = sum(hexReg[i].Q_flow_2 for i in 1:nReg);
  
  // air stream connections
  for i in 2:nReg loop
    connect(hexReg[i].port_a2, hexReg[i-1].port_b2);
  end for;
  connect(ducMan_a.port_b, hexReg[1].port_a2);
  connect(hexReg[nReg].port_b2, ducMan_b.port_b);
  connect(pipMan_a.port_b, hexReg[1].port_a1);
  connect(hexReg[nReg].port_b1, pipMan_b.port_b);
  connect(pipMan_b.port_a, port_b1);
  connect(ducMan_b.port_a, port_b2);
  for i in 1:2:nReg loop
    
  // header after first hex register
    connect(hexReg[i].port_b1, hea1[(i+1)/2].port_a);
    connect(hea1[(i+1)/2].port_b, hexReg[i+1].port_b1);
  end for;
  // header after 2nd hex register
  for i in 2:2:(nReg-1) loop
    connect(hexReg[i].port_a1, hea2[i/2].port_a);
    connect(hea2[i/2].port_b, hexReg[i+1].port_a1);
  end for;
  connect(port_a1, temSen_1.port_a);
  connect(temSen_1.port_b, masFloSen_1.port_a);
  connect(masFloSen_1.port_b, pipMan_a.port_a);
  connect(temSen_1.T, hAModel.T_1);
  connect(masFloSen_1.m_flow, hAModel.m_flow_1);
  connect(port_a2, masFloSen_2.port_a);
  connect(masFloSen_2.port_b, temSen_2.port_a);
  connect(temSen_2.port_b, ducMan_a.port_a);
  connect(temSen_2.T, hAModel.T_2);
  connect(masFloSen_2.m_flow, hAModel.m_flow_2);
  connect(hAModel.hA_1, gai_1.u);
  connect(hAModel.hA_2, gai_2.u);
  for i in 1:nReg loop
    connect(gai_1.y, hexReg[i].Gc_1);
    connect(gai_2.y, hexReg[i].Gc_2);
  end for;
end SensibleCoilDiscretized;

Buildings.HeatExchangers.SensibleHexHAInput

Simple heat exchanger with convective heat transfer as input

Buildings.HeatExchangers.SensibleHexHAInput

Information

Simple heat exchanger with convective heat transfer as input. The hA values are an input and energy storage in the metal and in the fluid is taken into account.

Parameters

Type	Name	Default	Description
Boolean	allowFlowReversal_1	flowDirection_1 == Modelica_...	= false, if flow only from port_a to port_b, otherwise reversing flow allowed
Boolean	allowFlowReversal_2	flowDirection_2 == Modelica_...	= false, if flow only from port_a to port_b, otherwise reversing flow allowed
Fluid 1
replaceable package Medium_1	PartialMedium	Fluid 1
Fluid 2
replaceable package Medium_2	PartialMedium	Fluid 2
Initialization
MassFlowRate	m_flow_1		Mass flow rate from port_a1 to port_b1 (m_flow_1 > 0 is design flow direction) [kg/s]
MassFlowRate	m_flow_2		Mass flow rate from port_a2 to port_b2 (m_flow_2 > 0 is design flow direction) [kg/s]
Pressure	dp_1		Pressure difference between port_a1 and port_b1 [Pa]
Pressure	dp_2		Pressure difference between port_a2 and port_b2 [Pa]
Nominal condition
Time	tau_1	60	Time constant at nominal flow [s]
MassFlowRate	m0_flow_1		Mass flow rate [kg/s]
Time	tau_2	60	Time constant at nominal flow [s]
MassFlowRate	m0_flow_2		Mass flow rate [kg/s]
ThermalConductance	UA0		Thermal conductance at nominal flow [W/K]
Time	tau_m	2	Time constant of metal [s]
Advanced
Temp	flowDirection_1	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component
Temp	flowDirection_2	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component

Connectors

Type	Name	Description
FluidPort_a	port_a1	Fluid connector a for medium 1 (positive design flow direction is from port_a1 to port_b1)
FluidPort_b	port_b1	Fluid connector b for medium 1 (positive design flow direction is from port_a to port_b)
FluidPort_a	port_a2	Fluid connector a for medium 2 (positive design flow direction is from port_a2 to port_b2)
FluidPort_b	port_b2	Fluid connector b for medium 2 (positive design flow direction is from port_a to port_b)
input RealInput	Gc_1	Signal representing the convective thermal conductance of fluid 1 in [W/K]
input RealInput	Gc_2	Signal representing the convective thermal conductance of fluid 2 in [W/K]

Modelica definition

model SensibleHexHAInput 
  "Simple heat exchanger with convective heat transfer as input" 
  extends Fluids.Interfaces.PartialDynamicFourPortTransformer(final C=tau_m*UA0);
  extends Buildings.BaseClasses.BaseIcon;
  
  
   parameter Modelica.SIunits.ThermalConductance UA0(min=0) 
    "Thermal conductance at nominal flow";
  parameter Modelica.SIunits.Time tau_m(min=0) = 2 "Time constant of metal";
  Modelica.Blocks.Interfaces.RealInput Gc_1(redeclare type SignalType = 
        Modelica.SIunits.ThermalConductance) 
    "Signal representing the convective thermal conductance of fluid 1 in [W/K]";
  Modelica.Blocks.Interfaces.RealInput Gc_2(redeclare type SignalType = 
        Modelica.SIunits.ThermalConductance) 
    "Signal representing the convective thermal conductance of fluid 2 in [W/K]";
equation 
  connect(Gc_1, con1.Gc);
  connect(Gc_2, con2.Gc);
end SensibleHexHAInput;

HTML-documentation generated by Dymola Fri Jun 20 09:58:33 2008.