Collection of models that illustrate model use and test models
Information
This package contains examples for the use of models that can be found in
Buildings.Fluid.HeatExchangers.
Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).
Package Content
Model that demonstrates use of a heat exchanger with constant effectiveness
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ConstantEffectiveness
"Model that demonstrates use of a heat exchanger with constant effectiveness"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
package Medium2 =
Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated;
Buildings.Fluid.Sources.Boundary_pT sin_2(
redeclare
package Medium = Medium2,
use_p_in=true,
nPorts=1,
T=273.15 + 10,
X={0.001,0.999});
Modelica.Blocks.Sources.Ramp PIn(
height=200,
duration=60,
offset=101325,
startTime=50);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare
package Medium = Medium2, T=273.15 + 5,
use_p_in=true,
use_T_in=true,
nPorts=1);
Modelica.Blocks.Sources.Ramp TWat(
height=10,
duration=60,
offset=273.15 + 30,
startTime=60)
"Water temperature";
Modelica.Blocks.Sources.Constant TDb(k=293.15)
"Drybulb temperature";
Modelica.Blocks.Sources.Constant POut(k=101325);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare
package Medium = Medium1,
use_p_in=true,
nPorts=1,
p=300000,
T=273.15 + 25);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
p=300000 + 5000,
T=273.15 + 50,
use_T_in=true,
nPorts=1);
Buildings.Fluid.HeatExchangers.ConstantEffectiveness hex(
redeclare package
Medium1 =
Medium1,
redeclare package Medium2 = Medium2,
show_T=true,
m1_flow_nominal=5,
m2_flow_nominal=5,
dp1_nominal=500,
dp2_nominal=10);
inner Modelica.Fluid.System system(
p_ambient=300000,
T_ambient=313.15);
Modelica.Blocks.Sources.Trapezoid trapezoid(
amplitude=5000,
rising=10,
width=100,
falling=10,
period=3600,
offset=300000);
equation
connect(PIn.y,sou_2. p_in);
connect(TDb.y, sou_2.T_in);
connect(TWat.y, sou_1.T_in);
connect(sou_1.ports[1], hex.port_a1);
connect(hex.port_a2, sou_2.ports[1]);
connect(POut.y, sin_2.p_in);
connect(hex.port_b1, sin_1.ports[1]);
connect(sin_2.ports[1], hex.port_b2);
connect(trapezoid.y, sin_1.p_in);
end ConstantEffectiveness;
Model of a cooling coil that tests variable mass flow rates
Information
Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.HeatExchangers.Examples.BaseClasses.EffectivenessNTUMassFlow (Partial model of epsilon-NTU coil that tests variable mass flow rates).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 5 + 273.15 | [K] |
| Temperature | T_b1_nominal | 10 + 273.15 | [K] |
| Temperature | T_a2_nominal | 30 + 273.15 | [K] |
| Temperature | T_b2_nominal | 15 + 273.15 | [K] |
| HeatFlowRate | Q_flow_nominal | m1_flow_nominal*4200*(T_a1_n... | Nominal heat transfer [W] |
| MassFlowRate | m1_flow_nominal | 0.1 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model DryCoilCounterFlowMassFlow
"Model of a cooling coil that tests variable mass flow rates"
extends Modelica.Icons.Example;
extends Buildings.Fluid.HeatExchangers.Examples.BaseClasses.EffectivenessNTUMassFlow
(
sou_1(nPorts=1),
sin_1(nPorts=1),
sou_2(nPorts=1),
sin_2(nPorts=1));
DryCoilCounterFlow hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
show_T=true,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
dp2_nominal(displayUnit="Pa") = 200,
allowFlowReversal1=true,
allowFlowReversal2=true,
dp1_nominal(displayUnit="Pa") = 3000,
UA_nominal=Q_flow_nominal/
Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(
T_a1_nominal,
T_b1_nominal,
T_a2_nominal,
T_b2_nominal));
inner Modelica.Fluid.System system;
Sensors.RelativeHumidityTwoPort senRelHum(
redeclare package Medium
= Medium2, m_flow_nominal=m2_flow_nominal);
equation
connect(sou_1.ports[1], hex.port_a1);
connect(hex.port_b1, sin_1.ports[1]);
connect(hex.port_a2, sou_2.ports[1]);
connect(senRelHum.port_a, hex.port_b2);
connect(senRelHum.port_b, sin_2.ports[1]);
end DryCoilCounterFlowMassFlow;
Model that demonstrates use of a heat exchanger without condensation and with feedback control
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 5 + 273.15 | [K] |
| Temperature | T_b1_nominal | 10 + 273.15 | [K] |
| Temperature | T_a2_nominal | 30 + 273.15 | [K] |
| Temperature | T_b2_nominal | 15 + 273.15 | [K] |
| MassFlowRate | m1_flow_nominal | 0.1 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model DryCoilCounterFlowPControl
"Model that demonstrates use of a heat exchanger without condensation and with feedback control"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
package Medium2 =
Buildings.Media.PerfectGases.MoistAirUnsaturated;
//package Medium2 = Buildings.Media.GasesPTDecoupled.MoistAir;
//package Medium2 = Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated;
//package Medium2 = Buildings.Media.GasesConstantDensity.MoistAir;
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.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,
nPorts=1,
use_p_in=false,
p(displayUnit="Pa") = 101325,
T=303.15);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare package Medium = Medium2,
nPorts=1,
T=T_a2_nominal,
X={0.02,1 - 0.02},
use_T_in=true,
use_X_in=true,
p(displayUnit="Pa") = 101325 + 300);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare package Medium = Medium1,
nPorts=1,
use_p_in=false,
p=300000,
T=293.15);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
nPorts=1,
use_T_in=true,
p=300000 + 12000);
Fluid.FixedResistances.FixedResistanceDpM res_2(
from_dp=true,
redeclare package Medium = Medium2,
dp_nominal=100,
m_flow_nominal=m2_flow_nominal);
Fluid.FixedResistances.FixedResistanceDpM res_1(
from_dp=true,
redeclare package Medium = Medium1,
dp_nominal=3000,
m_flow_nominal=m1_flow_nominal);
Buildings.Fluid.Sensors.TemperatureTwoPort temSen(
redeclare package Medium =
Medium2, m_flow_nominal=m2_flow_nominal);
Buildings.Fluid.Actuators.Valves.TwoWayEqualPercentage val(
redeclare package Medium = Medium1,
m_flow_nominal=m1_flow_nominal,
dpValve_nominal=6000)
"Valve model";
Modelica.Blocks.Sources.TimeTable TSet(table=[0,288.15; 600,288.15; 600,
298.15; 1200,298.15; 1800,283.15; 2400,283.15; 2400,288.15])
"Setpoint temperature";
Buildings.Fluid.HeatExchangers.DryCoilCounterFlow hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
dp2_nominal(displayUnit="Pa") = 200,
allowFlowReversal1=true,
allowFlowReversal2=true,
dp1_nominal(displayUnit="Pa") = 3000,
UA_nominal=m1_flow_nominal*4200*(T_a1_nominal - T_b1_nominal)/
Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(
T_a1_nominal,
T_b1_nominal,
T_a2_nominal,
T_b2_nominal),
show_T=true);
inner Modelica.Fluid.System system;
Modelica.Blocks.Sources.Constant const(k=0.8);
Buildings.Utilities.Psychrometrics.X_pTphi x_pTphi(use_p_in=false);
Modelica.Blocks.Sources.Constant const1(k=T_a2_nominal);
Buildings.Controls.Continuous.LimPID con(
Td=1,
reverseAction=true,
yMin=0,
controllerType=Modelica.Blocks.Types.SimpleController.PI,
k=0.1,
Ti=60)
"Controller";
Modelica.Blocks.Sources.Ramp TWat(
height=30,
offset=T_a1_nominal,
startTime=300,
duration=2000)
"Water temperature, raised to high value at t=3000 s";
equation
connect(hex.port_b1, res_1.port_a);
connect(val.port_b, hex.port_a1);
connect(sou_1.ports[1], val.port_a);
connect(sin_1.ports[1], res_1.port_b);
connect(sin_2.ports[1], res_2.port_b);
connect(sou_2.ports[1], hex.port_a2);
connect(temSen.port_b, res_2.port_a);
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(TSet.y, con.u_s);
connect(temSen.T, con.u_m);
connect(TWat.y, sou_1.T_in);
connect(con.y, val.y);
connect(temSen.port_a, hex.port_b2);
end DryCoilCounterFlowPControl;
Model that demonstrates use of a finite volume model of a heat exchanger without condensation
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 60 + 273.15 | [K] |
| Temperature | T_b1_nominal | 40 + 273.15 | [K] |
| Temperature | T_a2_nominal | 5 + 273.15 | [K] |
| Temperature | T_b2_nominal | 20 + 273.15 | [K] |
| MassFlowRate | m1_flow_nominal | 5 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model DryCoilDiscretized
"Model that demonstrates use of a finite volume model of a heat exchanger without condensation"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
package Medium2 =
Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated;
parameter Modelica.SIunits.Temperature T_a1_nominal = 60+273.15;
parameter Modelica.SIunits.Temperature T_b1_nominal = 40+273.15;
parameter Modelica.SIunits.Temperature T_a2_nominal = 5+273.15;
parameter Modelica.SIunits.Temperature T_b2_nominal = 20+273.15;
parameter Modelica.SIunits.MassFlowRate m1_flow_nominal = 5
"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.HeatExchangers.DryCoilDiscretized hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
nPipPar=1,
nPipSeg=3,
nReg=2,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
UA_nominal=m1_flow_nominal*4200*(T_a1_nominal-T_b1_nominal)/
Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(
T_a1_nominal,
T_b1_nominal,
T_a2_nominal,
T_b2_nominal),
dp2_nominal=200,
dp1_nominal=5000,
show_T=true,
energyDynamics1=Modelica.Fluid.Types.Dynamics.SteadyStateInitial,
energyDynamics2=Modelica.Fluid.Types.Dynamics.SteadyStateInitial);
Buildings.Fluid.Sources.Boundary_pT sin_2(
redeclare
package Medium = Medium2, T=303.15,
use_p_in=true,
nPorts=1);
Modelica.Blocks.Sources.Ramp PIn(
offset=101525,
height=-199,
duration=60,
startTime=120);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare
package Medium = Medium2,
use_p_in=true,
use_T_in=true,
T=283.15,
nPorts=1);
Modelica.Blocks.Sources.Ramp TWat(
duration=60,
startTime=60,
height=5,
offset=273.15 + 60)
"Water temperature";
Modelica.Blocks.Sources.Constant TDb(k=273.15 + 5)
"Drybulb temperature";
Modelica.Blocks.Sources.Constant POut(k=101325);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare
package Medium = Medium1,
p=300000,
T=293.15,
use_p_in=true,
nPorts=1);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
p=300000 + 5000,
use_T_in=true,
T=293.15,
nPorts=1);
Modelica.Blocks.Sources.Ramp PSin_1(
startTime=240,
offset=300000,
height=4990,
duration=60);
inner Modelica.Fluid.System system;
equation
connect(PIn.y,sou_2. p_in);
connect(TDb.y, sou_2.T_in);
connect(TWat.y, sou_1.T_in);
connect(PSin_1.y, sin_1.p_in);
connect(sou_1.ports[1], hex.port_a1);
connect(sou_2.ports[1], hex.port_a2);
connect(POut.y, sin_2.p_in);
connect(sin_2.ports[1], hex.port_b2);
connect(hex.port_b1, sin_1.ports[1]);
end DryCoilDiscretized;
Model that demonstrates use of a finite volume model of a heat exchanger without condensation and with feedback control
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 60 + 273.15 | [K] |
| Temperature | T_b1_nominal | 50 + 273.15 | [K] |
| Temperature | T_a2_nominal | 20 + 273.15 | [K] |
| Temperature | T_b2_nominal | 40 + 273.15 | [K] |
| MassFlowRate | m1_flow_nominal | 5 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model DryCoilDiscretizedPControl
"Model that demonstrates use of a finite volume model of a heat exchanger without condensation and with feedback control"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
//package Medium2 = Buildings.Media.PerfectGases.MoistAir;
//package Medium2 = Buildings.Media.GasesPTDecoupled.MoistAir;
// package Medium2 = Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated;
package Medium2 =
Buildings.Media.GasesPTDecoupled.SimpleAir;
parameter Modelica.SIunits.Temperature T_a1_nominal = 60+273.15;
parameter Modelica.SIunits.Temperature T_b1_nominal = 50+273.15;
parameter Modelica.SIunits.Temperature T_a2_nominal = 20+273.15;
parameter Modelica.SIunits.Temperature T_b2_nominal = 40+273.15;
parameter Modelica.SIunits.MassFlowRate m1_flow_nominal = 5
"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=303.15,
nPorts=1);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare
package Medium = Medium2,
nPorts=1,
use_p_in=false,
use_T_in=false,
p(displayUnit="Pa") = 101625,
T=T_a2_nominal);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare
package Medium = Medium1,
p=300000,
T=293.15,
use_p_in=true,
nPorts=1);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
p=300000 + 9000,
nPorts=1,
use_T_in=false,
T=T_a1_nominal);
Modelica.Blocks.Sources.Ramp PSin_1(
duration=60,
height=5000,
startTime=240,
offset=300000);
Buildings.Fluid.Sensors.TemperatureTwoPort temSen(
redeclare package Medium =
Medium2, m_flow_nominal=m2_flow_nominal);
Buildings.Fluid.Actuators.Valves.TwoWayEqualPercentage val(
redeclare package Medium = Medium1,
l=0.005,
m_flow_nominal=m1_flow_nominal,
filteredOpening=false,
dpFixed_nominal=2000 + 3000,
dpValve_nominal=6000)
"Valve model";
Modelica.Blocks.Sources.TimeTable TSet(table=[0,298.15; 600,298.15; 600,
303.15; 1200,303.15; 1800,298.15; 2400,298.15; 2400,304.15])
"Setpoint temperature";
Buildings.Fluid.HeatExchangers.DryCoilDiscretized hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
show_T=true,
nPipPar=1,
nPipSeg=3,
nReg=4,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
UA_nominal=m1_flow_nominal*4200*(T_a1_nominal-T_b1_nominal)/
Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(
T_a1_nominal,
T_b1_nominal,
T_a2_nominal,
T_b2_nominal),
dp1_nominal(displayUnit="Pa") = 0,
dp2_nominal(displayUnit="Pa") = 300);
Buildings.Fluid.Actuators.Motors.IdealMotor mot(tOpe=60)
"Motor model";
inner Modelica.Fluid.System system;
Buildings.Controls.Continuous.LimPID con(
k=1,
Ti=60,
controllerType=Modelica.Blocks.Types.SimpleController.P,
Td=60)
"Controller";
equation
connect(PSin_1.y, sin_1.p_in);
connect(val.port_b, hex.port_a1);
connect(sou_1.ports[1], val.port_a);
connect(sou_2.ports[1], hex.port_a2);
connect(mot.y, val.y);
connect(hex.port_b2, temSen.port_a);
connect(TSet.y, con.u_s);
connect(temSen.T, con.u_m);
connect(con.y, mot.u);
connect(hex.port_b1, sin_1.ports[1]);
connect(temSen.port_b, sin_2.ports[1]);
end DryCoilDiscretizedPControl;
Model that demonstrates use of a heat exchanger without condensation that uses the epsilon-NTU relation
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| SpecificHeatCapacity | cp1 | Medium1.specificHeatCapacity... | Specific heat capacity of medium 2 [J/(kg.K)] |
| SpecificHeatCapacity | cp2 | Medium2.specificHeatCapacity... | Specific heat capacity of medium 2 [J/(kg.K)] |
| MassFlowRate | m1_flow | 5 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow | m1_flow*cp1/cp2 | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model DryEffectivenessNTU
"Model that demonstrates use of a heat exchanger without condensation that uses the epsilon-NTU relation"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
package Medium2 =
Buildings.Media.IdealGases.SimpleAir;
parameter Modelica.SIunits.SpecificHeatCapacity cp1=
Medium1.specificHeatCapacityCp(
Medium1.setState_pTX(Medium1.p_default, Medium1.T_default, Medium1.X_default))
"Specific heat capacity of medium 2";
parameter Modelica.SIunits.SpecificHeatCapacity cp2=
Medium2.specificHeatCapacityCp(
Medium2.setState_pTX(Medium2.p_default, Medium2.T_default, Medium2.X_default))
"Specific heat capacity of medium 2";
parameter Modelica.SIunits.MassFlowRate m1_flow = 5
"Nominal mass flow rate medium 1";
parameter Modelica.SIunits.MassFlowRate m2_flow = m1_flow*cp1/
cp2
"Nominal mass flow rate medium 2";
Buildings.Fluid.Sources.Boundary_pT sin_2(
redeclare
package Medium = Medium2,
use_p_in=true,
nPorts=5,
T=273.15 + 10);
Modelica.Blocks.Sources.Ramp PIn(
height=200,
duration=60,
offset=101325,
startTime=100);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare
package Medium = Medium2, T=273.15 + 5,
use_p_in=true,
use_T_in=true,
nPorts=5);
Modelica.Blocks.Sources.Ramp TWat(
height=10,
duration=60,
offset=273.15 + 30,
startTime=60)
"Water temperature";
Modelica.Blocks.Sources.Constant TDb(k=293.15)
"Drybulb temperature";
Modelica.Blocks.Sources.Constant POut(k=101325);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare
package Medium = Medium1,
use_p_in=true,
nPorts=5,
p=300000,
T=273.15 + 25);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
p=300000 + 5000,
T=273.15 + 50,
use_T_in=true,
nPorts=5);
Buildings.Fluid.HeatExchangers.DryEffectivenessNTU hexPar(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
dp1_nominal=500,
dp2_nominal=10,
m1_flow_nominal=m1_flow,
m2_flow_nominal=m2_flow,
Q_flow_nominal=m2_flow*cp2*(24 - 20),
configuration=Buildings.Fluid.Types.HeatExchangerConfiguration.ParallelFlow,
show_T=true,
T_a1_nominal=303.15,
T_a2_nominal=293.15);
inner Modelica.Fluid.System system(
p_ambient=300000,
T_ambient=313.15);
Buildings.Fluid.HeatExchangers.DryEffectivenessNTU hexCou(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
dp1_nominal=500,
dp2_nominal=10,
m1_flow_nominal=m1_flow,
m2_flow_nominal=m2_flow,
Q_flow_nominal=m2_flow*cp2*(24 - 20),
configuration=Buildings.Fluid.Types.HeatExchangerConfiguration.CounterFlow,
show_T=true,
T_a1_nominal=303.15,
T_a2_nominal=293.15);
Buildings.Fluid.HeatExchangers.DryEffectivenessNTU hexCroC1Mix(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
dp1_nominal=500,
dp2_nominal=10,
m1_flow_nominal=m1_flow,
m2_flow_nominal=m2_flow,
Q_flow_nominal=m2_flow*cp2*(24 - 20),
configuration=Buildings.Fluid.Types.HeatExchangerConfiguration.CrossFlowStream1MixedStream2Unmixed,
show_T=true,
T_a1_nominal=303.15,
T_a2_nominal=293.15);
Buildings.Fluid.HeatExchangers.DryEffectivenessNTU hexCroC1Unm(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
dp1_nominal=500,
dp2_nominal=10,
m1_flow_nominal=m1_flow,
m2_flow_nominal=m2_flow,
Q_flow_nominal=m2_flow*cp2*(24 - 20),
configuration=Buildings.Fluid.Types.HeatExchangerConfiguration.CrossFlowStream1UnmixedStream2Mixed,
show_T=true,
T_a1_nominal=303.15,
T_a2_nominal=293.15);
Buildings.Fluid.HeatExchangers.DryEffectivenessNTU hexCroUnm(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
dp1_nominal=500,
dp2_nominal=10,
m1_flow_nominal=m1_flow,
m2_flow_nominal=m2_flow,
Q_flow_nominal=m2_flow*cp2*(24 - 20),
configuration=Buildings.Fluid.Types.HeatExchangerConfiguration.CrossFlowUnmixed,
show_T=true,
T_a1_nominal=303.15,
T_a2_nominal=293.15);
Modelica.Blocks.Sources.Trapezoid trapezoid(
amplitude=5000,
rising=10,
width=100,
falling=10,
period=3600,
offset=300000);
equation
connect(PIn.y,sou_2. p_in);
connect(TDb.y, sou_2.T_in);
connect(TWat.y, sou_1.T_in);
connect(sou_1.ports[1], hexPar.port_a1);
connect(hexPar.port_a2, sou_2.ports[1]);
connect(POut.y, sin_2.p_in);
connect(hexPar.port_b1, sin_1.ports[1]);
connect(sin_2.ports[1], hexPar.port_b2);
connect(hexCou.port_a1, sou_1.ports[2]);
connect(hexCroC1Mix.port_a1, sou_1.ports[3]);
connect(hexCroC1Unm.port_a1, sou_1.ports[4]);
connect(hexCou.port_b2, sin_2.ports[2]);
connect(hexCroC1Mix.port_b2, sin_2.ports[3]);
connect(hexCroC1Unm.port_b2, sin_2.ports[4]);
connect(hexCou.port_b1, sin_1.ports[2]);
connect(hexCroC1Mix.port_b1, sin_1.ports[3]);
connect(hexCroC1Unm.port_b1, sin_1.ports[4]);
connect(hexCou.port_a2, sou_2.ports[2]);
connect(hexCroC1Mix.port_a2, sou_2.ports[3]);
connect(hexCroC1Unm.port_a2, sou_2.ports[4]);
connect(hexCroUnm.port_a1, sou_1.ports[5]);
connect(hexCroUnm.port_b2, sin_2.ports[5]);
connect(hexCroUnm.port_b1, sin_1.ports[5]);
connect(hexCroUnm.port_a2, sou_2.ports[5]);
connect(trapezoid.y, sin_1.p_in);
end DryEffectivenessNTU;
Model of epsilon-NTU dry coil that tests variable mass flow rates
Information
Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.HeatExchangers.Examples.BaseClasses.EffectivenessNTUMassFlow (Partial model of epsilon-NTU coil that tests variable mass flow rates).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 5 + 273.15 | [K] |
| Temperature | T_b1_nominal | 10 + 273.15 | [K] |
| Temperature | T_a2_nominal | 30 + 273.15 | [K] |
| Temperature | T_b2_nominal | 15 + 273.15 | [K] |
| HeatFlowRate | Q_flow_nominal | m1_flow_nominal*4200*(T_a1_n... | Nominal heat transfer [W] |
| MassFlowRate | m1_flow_nominal | 0.1 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model DryEffectivenessNTUMassFlow
"Model of epsilon-NTU dry coil that tests variable mass flow rates"
extends Modelica.Icons.Example;
extends Buildings.Fluid.HeatExchangers.Examples.BaseClasses.EffectivenessNTUMassFlow
(
sou_1(nPorts=1),
sin_1(nPorts=1),
sou_2(nPorts=1),
sin_2(nPorts=1));
Buildings.Fluid.HeatExchangers.DryEffectivenessNTU hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
dp2_nominal(displayUnit="Pa") = 200,
configuration=Buildings.Fluid.Types.HeatExchangerConfiguration.CounterFlow,
allowFlowReversal1=true,
allowFlowReversal2=true,
dp1_nominal(displayUnit="Pa") = 3000,
Q_flow_nominal=Q_flow_nominal,
T_a1_nominal=T_a1_nominal,
T_a2_nominal=T_a2_nominal,
show_T=true);
Buildings.Fluid.Sensors.RelativeHumidityTwoPort senRelHum(
redeclare package Medium
= Medium2, m_flow_nominal=m2_flow_nominal,
initType=Modelica.Blocks.Types.Init.InitialState);
equation
connect(sou_1.ports[1], hex.port_a1);
connect(hex.port_b1, sin_1.ports[1]);
connect(hex.port_a2, sou_2.ports[1]);
connect(senRelHum.port_a, hex.port_b2);
connect(senRelHum.port_b, sin_2.ports[1]);
end DryEffectivenessNTUMassFlow;
Model that demonstrates use of a heat exchanger without condensation that uses the epsilon-NTU relation with feedback control
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 60 + 273.15 | Temperature at nominal conditions as port a1 [K] |
| Temperature | T_b1_nominal | 50 + 273.15 | Temperature at nominal conditions as port b1 [K] |
| Temperature | T_a2_nominal | 20 + 273.15 | Temperature at nominal conditions as port a2 [K] |
| Temperature | T_b2_nominal | 40 + 273.15 | Temperature at nominal conditions as port b2 [K] |
| MassFlowRate | m1_flow_nominal | 5 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model DryEffectivenessNTUPControl
"Model that demonstrates use of a heat exchanger without condensation that uses the epsilon-NTU relation with feedback control"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
//package Medium2 = Buildings.Media.PerfectGases.MoistAir;
//package Medium2 = Buildings.Media.GasesPTDecoupled.MoistAir;
// package Medium2 = Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated;
package Medium2 =
Buildings.Media.GasesPTDecoupled.SimpleAir;
parameter Modelica.SIunits.Temperature T_a1_nominal = 60+273.15
"Temperature at nominal conditions as port a1";
parameter Modelica.SIunits.Temperature T_b1_nominal = 50+273.15
"Temperature at nominal conditions as port b1";
parameter Modelica.SIunits.Temperature T_a2_nominal = 20+273.15
"Temperature at nominal conditions as port a2";
parameter Modelica.SIunits.Temperature T_b2_nominal = 40+273.15
"Temperature at nominal conditions as port b2";
parameter Modelica.SIunits.MassFlowRate m1_flow_nominal = 5
"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=303.15,
nPorts=1);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare
package Medium = Medium2,
nPorts=1,
use_p_in=false,
use_T_in=false,
p(displayUnit="Pa") = 101625,
T=T_a2_nominal);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare
package Medium = Medium1,
use_p_in=false,
p=300000,
T=293.15,
nPorts=1);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
p=300000 + 9000,
nPorts=1,
use_T_in=false,
T=T_a1_nominal);
Buildings.Fluid.Sensors.TemperatureTwoPort temSen(
redeclare package Medium =
Medium2, m_flow_nominal=m2_flow_nominal);
Buildings.Fluid.Actuators.Valves.TwoWayEqualPercentage val(
redeclare package Medium = Medium1,
l=0.005,
m_flow_nominal=m1_flow_nominal,
dpFixed_nominal=2000 + 3000,
dpValve_nominal=6000)
"Valve model";
Buildings.Controls.Continuous.LimPID P(
controllerType=Modelica.Blocks.Types.SimpleController.PI,
Ti=30,
k=0.1,
Td=1);
Modelica.Blocks.Sources.Pulse TSet(
amplitude=5,
period=3600,
offset=273.15 + 22)
"Setpoint temperature";
Buildings.Fluid.HeatExchangers.DryEffectivenessNTU hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
show_T=true,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
Q_flow_nominal=m1_flow_nominal*4200*(T_a1_nominal-T_b1_nominal),
configuration=Buildings.Fluid.Types.HeatExchangerConfiguration.CounterFlow,
T_a1_nominal=T_a1_nominal,
T_a2_nominal=T_a2_nominal,
dp1_nominal(displayUnit="Pa") = 0,
dp2_nominal(displayUnit="Pa") = 200 + 100);
inner Modelica.Fluid.System system;
equation
connect(val.port_b, hex.port_a1);
connect(sou_1.ports[1], val.port_a);
connect(sou_2.ports[1], hex.port_a2);
connect(hex.port_b2, temSen.port_a);
connect(TSet.y, P.u_s);
connect(temSen.T, P.u_m);
connect(P.y, val.y);
connect(hex.port_b1, sin_1.ports[1]);
connect(temSen.port_b, sin_2.ports[1]);
end DryEffectivenessNTUPControl;
Model that demonstrates the ideal heater model
Information
Model that demonstrates the use of an ideal heater.
Both heater models are identical, except that one model is configured
as a steady-state model, whereas the other is configured as a dynamic model.
Both heaters add heat to the medium to track a set-point for the outlet
temperature.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| MassFlowRate | m_flow_nominal | 3000/1000/20 | Nominal mass flow rate [kg/s] |
Modelica definition
model HeaterCoolerPrescribed
"Model that demonstrates the ideal heater model"
extends Modelica.Icons.Example;
package Medium =
Buildings.Media.GasesConstantDensity.SimpleAir;
inner Modelica.Fluid.System system(
m_flow_start=0,
energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState)
"System wide declarations";
parameter Modelica.SIunits.MassFlowRate
m_flow_nominal=3000/1000/20
"Nominal mass flow rate";
Buildings.Fluid.Sources.Boundary_pT sin(
redeclare package Medium = Medium,
use_T_in=false,
p(displayUnit="Pa"),
T=293.15,
nPorts=2)
"Sink";
Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed heaSte(
redeclare package Medium = Medium,
m_flow_nominal=m_flow_nominal,
dp_nominal=6000,
Q_flow_nominal=3000,
energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState)
"Steady-state model of the heater";
Buildings.Fluid.Sensors.TemperatureTwoPort senTem1(
redeclare package Medium = Medium,
m_flow_nominal=m_flow_nominal)
"Temperature sensor";
Modelica.Blocks.Sources.TimeTable TSet(table=[0, 273.15 + 20; 120, 273.15 +
20; 120, 273.15 + 30; 1200, 273.15 + 30])
"Setpoint";
Buildings.Controls.Continuous.LimPID con1(
controllerType=Modelica.Blocks.Types.SimpleController.PI,
Td=1,
k=1,
Ti=10)
"Controller";
Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed heaDyn(
redeclare package Medium = Medium,
m_flow_nominal=m_flow_nominal,
dp_nominal=6000,
Q_flow_nominal=3000,
energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyStateInitial)
"Dynamic model of the heater";
Buildings.Fluid.Sensors.TemperatureTwoPort senTem2(
redeclare package Medium
= Medium, m_flow_nominal=m_flow_nominal)
"Temperature sensor";
Buildings.Controls.Continuous.LimPID con2(
controllerType=Modelica.Blocks.Types.SimpleController.PI,
Td=1,
Ti=10,
k=0.1)
"Controller";
Sources.MassFlowSource_T sou(
redeclare package Medium = Medium,
use_T_in=false,
nPorts=2,
m_flow=2*m_flow_nominal,
T=293.15)
"Source";
equation
connect(senTem1.T, con1.u_m);
connect(TSet.y, con1.u_s);
connect(con1.y, heaSte.u);
connect(heaSte.port_b, senTem1.port_a);
connect(senTem2.T, con2.u_m);
connect(TSet.y, con2.u_s);
connect(con2.y, heaDyn.u);
connect(heaDyn.port_b, senTem2.port_a);
connect(heaSte.port_a, sou.ports[1]);
connect(sou.ports[2], heaDyn.port_a);
connect(senTem2.port_b, sin.ports[1]);
connect(senTem1.port_b, sin.ports[2]);
end HeaterCoolerPrescribed;
Model of a cooling coil that tests variable mass flow rates
Information
Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.HeatExchangers.Examples.BaseClasses.EffectivenessNTUMassFlow (Partial model of epsilon-NTU coil that tests variable mass flow rates).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 5 + 273.15 | [K] |
| Temperature | T_b1_nominal | 10 + 273.15 | [K] |
| Temperature | T_a2_nominal | 30 + 273.15 | [K] |
| Temperature | T_b2_nominal | 15 + 273.15 | [K] |
| HeatFlowRate | Q_flow_nominal | m1_flow_nominal*4200*(T_a1_n... | Nominal heat transfer [W] |
| MassFlowRate | m1_flow_nominal | 0.1 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model WetCoilCounterFlowMassFlow
"Model of a cooling coil that tests variable mass flow rates"
extends Modelica.Icons.Example;
extends Buildings.Fluid.HeatExchangers.Examples.BaseClasses.EffectivenessNTUMassFlow
(
sou_1(nPorts=1),
sin_1(nPorts=1),
sou_2(nPorts=1),
sin_2(nPorts=1));
WetCoilCounterFlow hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
dp2_nominal(displayUnit="Pa") = 200,
allowFlowReversal1=true,
allowFlowReversal2=true,
dp1_nominal(displayUnit="Pa") = 3000,
UA_nominal=Q_flow_nominal/
Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(
T_a1_nominal,
T_b1_nominal,
T_a2_nominal,
T_b2_nominal),
show_T=true);
inner Modelica.Fluid.System system;
Sensors.RelativeHumidityTwoPort senRelHum(
redeclare package Medium = Medium2,
m_flow_nominal=m2_flow_nominal);
equation
connect(sou_1.ports[1], hex.port_a1);
connect(hex.port_b1, sin_1.ports[1]);
connect(hex.port_a2, sou_2.ports[1]);
connect(hex.port_b2, senRelHum.port_a);
connect(senRelHum.port_b, sin_2.ports[1]);
end WetCoilCounterFlowMassFlow;
Model that demonstrates use of a heat exchanger with condensation and with feedback control
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 5 + 273.15 | [K] |
| Temperature | T_b1_nominal | 10 + 273.15 | [K] |
| Temperature | T_a2_nominal | 30 + 273.15 | [K] |
| Temperature | T_b2_nominal | 15 + 273.15 | [K] |
| MassFlowRate | m1_flow_nominal | 0.1 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model WetCoilCounterFlowPControl
"Model that demonstrates use of a heat exchanger with condensation and with feedback control"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
package Medium2 =
Buildings.Media.PerfectGases.MoistAirUnsaturated;
//package Medium2 = Buildings.Media.GasesPTDecoupled.MoistAir;
//package Medium2 = Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated;
//package Medium2 = Buildings.Media.GasesConstantDensity.MoistAir;
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.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,
nPorts=1,
use_p_in=false,
p(displayUnit="Pa") = 101325,
T=303.15);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare package Medium = Medium2,
nPorts=1,
T=T_a2_nominal,
X={0.02,1 - 0.02},
use_T_in=true,
use_X_in=true,
p(displayUnit="Pa") = 101325 + 300);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare package Medium = Medium1,
nPorts=1,
use_p_in=false,
p=300000,
T=293.15);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
nPorts=1,
use_T_in=true,
p=300000 + 12000);
Fluid.FixedResistances.FixedResistanceDpM res_2(
from_dp=true,
redeclare package Medium = Medium2,
dp_nominal=100,
m_flow_nominal=m2_flow_nominal);
Fluid.FixedResistances.FixedResistanceDpM res_1(
from_dp=true,
redeclare package Medium = Medium1,
dp_nominal=3000,
m_flow_nominal=m1_flow_nominal);
Buildings.Fluid.Sensors.TemperatureTwoPort temSen(
redeclare package Medium =
Medium2, m_flow_nominal=m2_flow_nominal);
Buildings.Fluid.Actuators.Valves.TwoWayEqualPercentage val(
redeclare package Medium = Medium1,
m_flow_nominal=m1_flow_nominal,
dpValve_nominal=6000)
"Valve model";
Modelica.Blocks.Sources.TimeTable TSet(table=[0,288.15; 600,288.15; 600,
298.15; 1200,298.15; 1800,283.15; 2400,283.15; 2400,288.15])
"Setpoint temperature";
Buildings.Fluid.HeatExchangers.WetCoilCounterFlow hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
dp2_nominal(displayUnit="Pa") = 200,
allowFlowReversal1=true,
allowFlowReversal2=true,
dp1_nominal(displayUnit="Pa") = 3000,
UA_nominal=2*m1_flow_nominal*4200*(T_a1_nominal - T_b1_nominal)/
Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(
T_a1_nominal,
T_b1_nominal,
T_a2_nominal,
T_b2_nominal),
show_T=true);
inner Modelica.Fluid.System system;
Modelica.Blocks.Sources.Constant const(k=0.8);
Buildings.Utilities.Psychrometrics.X_pTphi x_pTphi(use_p_in=false);
Modelica.Blocks.Sources.Constant const1(k=T_a2_nominal);
Buildings.Controls.Continuous.LimPID con(
Td=1,
reverseAction=true,
yMin=0,
controllerType=Modelica.Blocks.Types.SimpleController.PI,
k=0.1,
Ti=60)
"Controller";
Modelica.Blocks.Sources.Ramp TWat(
height=30,
offset=T_a1_nominal,
startTime=300,
duration=2000)
"Water temperature, raised to high value at t=3000 s";
equation
connect(hex.port_b1, res_1.port_a);
connect(val.port_b, hex.port_a1);
connect(sou_1.ports[1], val.port_a);
connect(sin_1.ports[1], res_1.port_b);
connect(sin_2.ports[1], res_2.port_b);
connect(sou_2.ports[1], hex.port_a2);
connect(hex.port_b2, temSen.port_a);
connect(temSen.port_b, res_2.port_a);
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(TSet.y, con.u_s);
connect(temSen.T, con.u_m);
connect(TWat.y, sou_1.T_in);
connect(con.y, val.y);
end WetCoilCounterFlowPControl;
Model that demonstrates use of a finite volume model of a heat exchanger with condensation
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 5 + 273.15 | [K] |
| Temperature | T_b1_nominal | 10 + 273.15 | [K] |
| Temperature | T_a2_nominal | 30 + 273.15 | [K] |
| Temperature | T_b2_nominal | 10 + 273.15 | [K] |
| MassFlowRate | m1_flow_nominal | 5 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model WetCoilDiscretized
"Model that demonstrates use of a finite volume model of a heat exchanger with condensation"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
package Medium2 =
Buildings.Media.GasesPTDecoupled.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 = 10+273.15;
parameter Modelica.SIunits.MassFlowRate m1_flow_nominal = 5
"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.HeatExchangers.WetCoilDiscretized hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
dp2_nominal(displayUnit="Pa") = 200,
nPipPar=1,
nPipSeg=3,
nReg=2,
dp1_nominal(displayUnit="Pa") = 5000,
UA_nominal=m1_flow_nominal*4200*(T_a1_nominal - T_b1_nominal)/
Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(
T_a1_nominal,
T_b1_nominal,
T_a2_nominal,
T_b2_nominal),
show_T=true);
Buildings.Fluid.Sources.Boundary_pT sin_2(
redeclare
package Medium = Medium2,
use_p_in=false,
p=101325,
T=303.15,
nPorts=1);
Modelica.Blocks.Sources.Ramp PIn(
duration=60,
height=-200,
startTime=120,
offset=101525);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare
package Medium = Medium2,
use_p_in=true,
nPorts=1,
use_T_in=false,
T=293.15);
Modelica.Blocks.Sources.Ramp TWat(
duration=60,
height=15,
offset=273.15 + 5,
startTime=120)
"Water temperature";
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare
package Medium = Medium1,
p=300000,
T=293.15,
use_p_in=true,
nPorts=1);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
p=300000 + 5000,
use_T_in=true,
T=293.15,
nPorts=1);
Modelica.Blocks.Sources.Ramp PSin_1(
duration=60,
height=5000,
startTime=240,
offset=300000);
inner Modelica.Fluid.System system;
equation
connect(TWat.y, sou_1.T_in);
connect(PSin_1.y, sin_1.p_in);
connect(sou_1.ports[1], hex.port_a1);
connect(sou_2.ports[1], hex.port_a2);
connect(PIn.y, sou_2.p_in);
connect(hex.port_b1, sin_1.ports[1]);
connect(hex.port_b2, sin_2.ports[1]);
end WetCoilDiscretized;
Model that demonstrates use of a finite volume model of a heat exchanger with condensation and feedback control
Information
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| Temperature | T_a1_nominal | 5 + 273.15 | [K] |
| Temperature | T_b1_nominal | 10 + 273.15 | [K] |
| Temperature | T_a2_nominal | 30 + 273.15 | [K] |
| Temperature | T_b2_nominal | 10 + 273.15 | [K] |
| MassFlowRate | m1_flow_nominal | 5 | Nominal mass flow rate medium 1 [kg/s] |
| MassFlowRate | m2_flow_nominal | m1_flow_nominal*4200/1000*(T... | Nominal mass flow rate medium 2 [kg/s] |
Modelica definition
model WetCoilDiscretizedPControl
"Model that demonstrates use of a finite volume model of a heat exchanger with condensation and feedback control"
extends Modelica.Icons.Example;
package Medium1 =
Buildings.Media.ConstantPropertyLiquidWater;
package Medium2 =
Buildings.Media.GasesConstantDensity.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 = 10+273.15;
parameter Modelica.SIunits.MassFlowRate m1_flow_nominal = 5
"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=101325,
T=303.15,
nPorts=1);
Buildings.Fluid.Sources.Boundary_pT sou_2(
redeclare
package Medium = Medium2,
nPorts=1,
use_p_in=false,
use_T_in=true,
p(displayUnit="Pa") = 101525,
T=293.15);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare
package Medium = Medium1,
p=300000,
T=293.15,
use_p_in=true,
nPorts=1);
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium1,
nPorts=1,
use_T_in=true,
p=300000 + 7000,
T=278.15);
Modelica.Blocks.Sources.Ramp PSin(
duration=60,
height=5000,
startTime=240,
offset=300000);
Buildings.Fluid.Sensors.TemperatureTwoPort temSen(
redeclare package Medium =
Medium2, m_flow_nominal=m2_flow_nominal);
Buildings.Fluid.Actuators.Valves.TwoWayLinear val(
redeclare package Medium = Medium1,
m_flow_nominal=m1_flow_nominal,
filteredOpening=false,
dpFixed_nominal=2000,
dpValve_nominal=5000);
Modelica.Blocks.Sources.TimeTable TSet(table=[0,293.15; 600,293.15; 600,
288.15; 1200,288.15; 1800,288.15; 2400,295.15; 2400,295.15])
"Setpoint temperature";
Buildings.Fluid.HeatExchangers.WetCoilDiscretized hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
show_T=true,
nPipPar=1,
nPipSeg=3,
nReg=4,
m1_flow_nominal=m1_flow_nominal,
m2_flow_nominal=m2_flow_nominal,
UA_nominal=m1_flow_nominal*4200*(T_a1_nominal-T_b1_nominal)/
Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(
T_a1_nominal,
T_b1_nominal,
T_a2_nominal,
T_b2_nominal),
dp2_nominal(displayUnit="Pa") = 200,
dp1_nominal(displayUnit="Pa") = 0);
inner Modelica.Fluid.System system;
Modelica.Blocks.Sources.Step TSou_2(
startTime=3000,
offset=T_a2_nominal,
height=-3);
Modelica.Blocks.Sources.Step TSou_1(
startTime=3000,
height=10,
offset=T_a1_nominal);
Buildings.Controls.Continuous.LimPID con(
k=1,
Ti=60,
controllerType=Modelica.Blocks.Types.SimpleController.P,
Td=60,
reverseAction=true)
"Controller";
Buildings.Fluid.Actuators.Motors.IdealMotor mot(tOpe=60)
"Motor model";
equation
connect(PSin.y, sin_1.p_in);
connect(sou_2.ports[1], hex.port_a2);
connect(hex.port_b2, temSen.port_a);
connect(val.port_b, hex.port_a1);
connect(sou_1.ports[1], val.port_a);
connect(TSou_2.y, sou_2.T_in);
connect(TSou_1.y, sou_1.T_in);
connect(TSet.y, con.u_s);
connect(temSen.T, con.u_m);
connect(con.y, mot.u);
connect(mot.y, val.y);
connect(sin_2.ports[1], temSen.port_b);
connect(hex.port_b1, sin_1.ports[1]);
end WetCoilDiscretizedPControl;
Automatically generated Thu Jun 19 10:56:28 2014.
ConstantEffectiveness
BaseClasses
Buildings.Fluid.HeatExchangers.Examples.ConstantEffectiveness