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.Interfaces.
Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).
Package Content
Model that tests the conservation equation
Information
Model that tests the conservation equations that are used
for the heat and mass balance.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ConservationEquation
"Model that tests the conservation equation"
extends Modelica.Icons.Example;
package Medium =
Buildings.Media.Water "Medium model";
Buildings.Fluid.Interfaces.ConservationEquation dyn(
redeclare package Medium
= Medium, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
nPorts=2,
fluidVolume=0.01)
"Dynamic conservation equation";
Buildings.Fluid.Interfaces.StaticTwoPortConservationEquation ste(
redeclare package Medium = Medium,
m_flow_nominal=0.01,
sensibleOnly=false,
show_T=true)
"Steady-state conservation equation";
Modelica.Blocks.Sources.Constant mWat_flow(k=0)
"Water mass flow rate added to the control volume";
Modelica.Blocks.Sources.TimeTable QSen_flow(startTime=0, table=[
0,-100;
900,-100;
900,0;
1800,0;
1800,100])
"Sensible heat flow rate added to the control volume";
Buildings.Fluid.Sources.Boundary_pT sin(
nPorts=2,
use_p_in=false,
redeclare package Medium = Medium,
p=101325,
T=283.15);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res1(
from_dp=true,
redeclare package Medium = Medium,
m_flow_nominal=0.01,
dp_nominal=100)
"Flow resistance";
Buildings.Fluid.Sources.MassFlowSource_T bou(
nPorts=2,
redeclare package Medium = Medium,
m_flow=0.01)
"Boundary condition for mass flow rate";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res2(
from_dp=true,
redeclare package Medium = Medium,
m_flow_nominal=0.01,
dp_nominal=100)
"Flow resistance";
equation
connect(QSen_flow.y, dyn.Q_flow);
connect(mWat_flow.y, dyn.mWat_flow);
connect(bou.ports[1], dyn.ports[1]);
connect(res1.port_b, sin.ports[1]);
connect(QSen_flow.y, ste.Q_flow);
connect(mWat_flow.y, ste.mWat_flow);
connect(res2.port_b, sin.ports[2]);
connect(ste.port_a, bou.ports[2]);
connect(ste.port_b, res2.port_a);
connect(dyn.ports[2], res1.port_a);
end ConservationEquation;
Model that tests a heat exchanger model with reverse flow
Information
Model that tests the basic class that is used for the heater models. It adds and removes heat for forward and reverse flow. The top and bottom models should give similar results, although the sign of the temperature difference over the components differ because of the reverse flow. The model uses assert statements that will be triggered if results that are expected to be close to each other differ by more than a prescribed threshold. All temperature sensors are configured as steady-state sensors to avoid differences in temperature due to the dynamic response of the sensor.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model HeaterCooler_u
"Model that tests a heat exchanger model with reverse flow"
extends Modelica.Icons.Example;
package Medium =
Buildings.Media.Water;
Buildings.Fluid.HeatExchangers.HeaterCooler_u hea1(
redeclare package Medium = Medium,
Q_flow_nominal=5000,
m_flow_nominal=0.5,
dp_nominal=200,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
massDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
"Heater and cooler";
Modelica.Blocks.Sources.Constant TDb(k=293.15)
"Drybulb temperature";
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium,
use_T_in=true,
nPorts=4,
p(displayUnit="Pa") = 101735,
T=293.15);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_11(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_12(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare
package Medium = Medium,
use_p_in=true,
T=288.15,
nPorts=4);
Modelica.Blocks.Sources.Constant POut(k=101325);
Modelica.Blocks.Sources.Ramp u(
height=2,
duration=3600,
offset=-1,
startTime=0)
"Control signal";
Buildings.Fluid.HeatExchangers.HeaterCooler_u hea2(
redeclare package Medium = Medium,
Q_flow_nominal=5000,
m_flow_nominal=0.5,
dp_nominal=200,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Heater and cooler";
Modelica.Blocks.Math.Gain gain(k=-1);
Buildings.Fluid.HeatExchangers.HeaterCooler_u hea3(
redeclare package Medium = Medium,
Q_flow_nominal=5000,
m_flow_nominal=0.5,
dp_nominal=200,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
massDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_2(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_3(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.HeatExchangers.HeaterCooler_u hea4(
redeclare package Medium = Medium, Q_flow_nominal=5000,
m_flow_nominal=0.5,
dp_nominal=200,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_4(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.MixingVolumes.MixingVolume mix1(
redeclare package Medium = Medium, V=
0.000001,
nPorts=2,
m_flow_nominal=0.5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial);
Buildings.Utilities.Diagnostics.AssertEquality ass1( threShold=
0.05, startTime=600);
Buildings.Utilities.Diagnostics.AssertEquality ass2( threShold=
0.05, startTime=600);
Buildings.Fluid.HeatExchangers.HeaterCooler_u hea5(
redeclare package Medium = Medium,
Q_flow_nominal=5000,
m_flow_nominal=0.5,
dp_nominal=200,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
massDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_1(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_5(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.HeatExchangers.HeaterCooler_u hea6(
redeclare package Medium =
Medium, Q_flow_nominal=5000,
m_flow_nominal=0.5,
dp_nominal=200,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Heater and cooler";
Buildings.Fluid.HeatExchangers.HeaterCooler_u hea7(
redeclare package Medium = Medium,
Q_flow_nominal=5000,
m_flow_nominal=0.5,
dp_nominal=200,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
massDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_6(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_7(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.HeatExchangers.HeaterCooler_u hea8(
redeclare package Medium = Medium, Q_flow_nominal=5000,
m_flow_nominal=0.5,
dp_nominal=200,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_8(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.MixingVolumes.MixingVolume mix2(
redeclare package Medium = Medium,
V=0.000001,
nPorts=2,
m_flow_nominal=0.5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial);
Buildings.Utilities.Diagnostics.AssertEquality ass9(
threShold=0.05, startTime=600);
Buildings.Utilities.Diagnostics.AssertEquality ass10(
threShold=0.05, startTime=600);
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem2a(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem2b(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem1a(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem1b(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem3a(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem3b(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem4a(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem4b(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Utilities.Diagnostics.AssertEquality ass3( threShold=
0.05, startTime=600);
Buildings.Utilities.Diagnostics.AssertEquality ass4( threShold=
0.05, startTime=600);
Buildings.Utilities.Diagnostics.AssertEquality ass5( threShold=
0.05, startTime=600);
Buildings.Utilities.Diagnostics.AssertEquality ass6( threShold=
0.05, startTime=600);
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem6b(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem6a(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem5b(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem5a(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Utilities.Diagnostics.AssertEquality ass7( threShold=
0.05, startTime=600);
Buildings.Utilities.Diagnostics.AssertEquality ass8( threShold=
0.05, startTime=600);
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem8b(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem8a(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem7b(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
Buildings.Fluid.Sensors.TemperatureTwoPort
senTem7a(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
tau=0)
"Temperature sensor";
equation
connect(POut.y,sin_1. p_in);
connect(TDb.y,sou_1. T_in);
connect(u.y, hea1.u);
connect(gain.y, hea2.u);
connect(u.y, gain.u);
connect(u.y, hea3.u);
connect(gain.y, hea4.u);
connect(u.y, hea6.u);
connect(u.y, hea8.u);
connect(gain.y, hea5.u);
connect(gain.y, hea7.u);
connect(sin_1.ports[1], res_12.port_a);
connect(sin_1.ports[2], res_3.port_a);
connect(sou_1.ports[1], res_11.port_a);
connect(sou_1.ports[2], res_2.port_a);
connect(sin_1.ports[3], res_1.port_a);
connect(sin_1.ports[4], res_6.port_a);
connect(sou_1.ports[3], res_5.port_a);
connect(sou_1.ports[4], res_7.port_a);
connect(mix1.ports[1], res_4.port_a);
connect(mix2.ports[1], res_8.port_a);
connect(senTem1a.T, ass1.u1);
connect(senTem2a.T, ass1.u2);
connect(senTem1b.T, ass2.u2);
connect(senTem2b.T, ass2.u1);
connect(senTem4a.T, ass4.u2);
connect(senTem3a.T, ass4.u1);
connect(senTem4b.T, ass3.u1);
connect(senTem3b.T, ass3.u2);
connect(senTem6a.T, ass6.u2);
connect(senTem5a.T, ass6.u1);
connect(senTem6b.T, ass5.u1);
connect(senTem5b.T, ass5.u2);
connect(senTem8a.T, ass8.u2);
connect(senTem7a.T, ass8.u1);
connect(senTem8b.T, ass7.u1);
connect(senTem7b.T, ass7.u2);
connect(senTem3a.T, ass10.u1);
connect(senTem7a.T, ass10.u2);
connect(senTem2b.T, ass9.u1);
connect(senTem5b.T, ass9.u2);
connect(res_12.port_b, senTem2a.port_a);
connect(senTem2a.port_b, hea2.port_a);
connect(hea2.port_b, senTem2b.port_a);
connect(senTem2b.port_b, senTem1b.port_b);
connect(hea1.port_b, senTem1b.port_a);
connect(res_11.port_b, senTem1a.port_a);
connect(senTem1a.port_b, hea1.port_a);
connect(res_2.port_b, senTem3a.port_a);
connect(senTem3a.port_b, hea3.port_a);
connect(hea3.port_b, senTem3b.port_a);
connect(senTem3b.port_b, mix1.ports[2]);
connect(hea4.port_b, senTem4b.port_a);
connect(res_3.port_b, senTem4a.port_a);
connect(senTem4a.port_b, hea4.port_a);
connect(senTem4b.port_b, res_4.port_b);
connect(res_5.port_b, senTem6a.port_a);
connect(senTem6a.port_b, hea6.port_a);
connect(hea6.port_b, senTem6b.port_a);
connect(senTem6b.port_b, senTem5b.port_b);
connect(senTem5b.port_a, hea5.port_b);
connect(hea5.port_a, senTem5a.port_b);
connect(senTem5a.port_a, res_1.port_b);
connect(res_7.port_b, senTem8a.port_a);
connect(senTem8a.port_b, hea8.port_a);
connect(hea8.port_b, senTem8b.port_a);
connect(senTem8b.port_b, res_8.port_b);
connect(mix2.ports[2], senTem7b.port_b);
connect(senTem7b.port_a, hea7.port_b);
connect(hea7.port_a, senTem7a.port_b);
connect(senTem7a.port_a, res_6.port_b);
end HeaterCooler_u;
Information
Model that tests the basic class that is used for the humidifier model.
It adds and removes water for forward and reverse flow.
The top and bottom models should give similar results, although
the sign of the humidity difference over the components differ
because of the reverse flow.
The model uses assert statements that will be triggered if
results that are expected to be close to each other differ by more
than a prescribed threshold.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| MassFlowRate | mWat_flow_nominal | 0.001 | Nominal water mass flow rate [kg/s] |
Modelica definition
model Humidifier_u
extends Modelica.Icons.Example;
package Medium =
Buildings.Media.Air;
parameter Modelica.SIunits.MassFlowRate mWat_flow_nominal = 0.001
"Nominal water mass flow rate";
Humidifier hea1(
redeclare package Medium =
Medium,
m_flow_nominal=0.5,
mWat_flow_nominal=mWat_flow_nominal,
dp_nominal=50,
show_T=true,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
massDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
"Heater and cooler";
Modelica.Blocks.Sources.Constant TDb(k=293.15)
"Drybulb temperature";
Buildings.Fluid.Sources.Boundary_pT sou_1(
redeclare package Medium = Medium,
use_T_in=true,
nPorts=4,
p(displayUnit="Pa") = 101435,
T=293.15);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_11(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_12(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.Sources.Boundary_pT sin_1(
redeclare package Medium = Medium,
use_p_in=true,
T=288.15,
nPorts=4);
Modelica.Blocks.Sources.Constant POut(k=101325);
Modelica.Blocks.Sources.Ramp u(
duration=3600,
startTime=0,
height=1,
offset=0)
"Control signal";
Humidifier hea2(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
mWat_flow_nominal=mWat_flow_nominal,
dp_nominal=50,
show_T=true,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Heater and cooler";
Modelica.Blocks.Math.Gain gain(k=-1);
Humidifier hea3(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
mWat_flow_nominal=mWat_flow_nominal,
dp_nominal=50,
show_T=true,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
massDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_2(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_3(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Humidifier hea4(
redeclare package Medium = Medium,
m_flow_nominal=0.5,
mWat_flow_nominal=mWat_flow_nominal,
dp_nominal=50,
show_T=true,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_4(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.MixingVolumes.MixingVolume mix1(
redeclare package Medium = Medium,
V=0.000001,
nPorts=2,
m_flow_nominal=0.5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial);
Buildings.Utilities.Diagnostics.AssertEquality ass1(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y1(y=hea2.staB.T);
Modelica.Blocks.Sources.RealExpression y2(y=hea1.staB.T);
Buildings.Utilities.Diagnostics.AssertEquality ass2(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y3(y=hea2.staA.T);
Modelica.Blocks.Sources.RealExpression y4(y=hea1.staA.T);
Buildings.Utilities.Diagnostics.AssertEquality ass3(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y5(y=hea4.staB.T);
Modelica.Blocks.Sources.RealExpression y6(y=hea3.staB.T);
Buildings.Utilities.Diagnostics.AssertEquality ass4(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y7(y=hea4.staA.T);
Modelica.Blocks.Sources.RealExpression y8(y=hea3.staA.T);
Humidifier hea5(
redeclare package Medium =
Medium,
m_flow_nominal=0.5,
mWat_flow_nominal=mWat_flow_nominal,
dp_nominal=50,
show_T=true,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
massDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_1(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_5(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Humidifier hea6(
redeclare package Medium =
Medium,
m_flow_nominal=0.5,
mWat_flow_nominal=mWat_flow_nominal,
dp_nominal=50,
show_T=true,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Heater and cooler";
Humidifier hea7(
redeclare package Medium =
Medium,
m_flow_nominal=0.5,
mWat_flow_nominal=mWat_flow_nominal,
dp_nominal=50,
show_T=true,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
massDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_6(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_7(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Humidifier hea8(
redeclare package Medium =
Medium,
m_flow_nominal=0.5,
mWat_flow_nominal=mWat_flow_nominal,
dp_nominal=50,
show_T=true,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Heater and cooler";
Buildings.Fluid.FixedResistances.FixedResistanceDpM res_8(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.MixingVolumes.MixingVolume mix2(
redeclare package Medium = Medium, V=
0.000001,
nPorts=2,
m_flow_nominal=0.5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial);
Buildings.Utilities.Diagnostics.AssertEquality ass5(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y9(y=hea6.staB.T);
Modelica.Blocks.Sources.RealExpression y10(
y=hea5.staB.T);
Buildings.Utilities.Diagnostics.AssertEquality ass6(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y11(
y=hea6.staA.T);
Modelica.Blocks.Sources.RealExpression y12(
y=hea5.staA.T);
Buildings.Utilities.Diagnostics.AssertEquality ass7(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y13(
y=hea8.staB.T);
Modelica.Blocks.Sources.RealExpression y14(
y=hea7.staB.T);
Buildings.Utilities.Diagnostics.AssertEquality ass8(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y15(
y=hea8.staA.T);
Modelica.Blocks.Sources.RealExpression y16(
y=hea7.staA.T);
Buildings.Utilities.Diagnostics.AssertEquality ass9(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y17(y=hea2.staB.T);
Modelica.Blocks.Sources.RealExpression y18(y=hea5.staB.T);
Buildings.Utilities.Diagnostics.AssertEquality ass10(
startTime=0.3,
threShold=0.05);
Modelica.Blocks.Sources.RealExpression y19(y=hea4.staA.T);
Modelica.Blocks.Sources.RealExpression y20(y=hea7.staA.T);
Buildings.Utilities.Diagnostics.AssertEquality ass11(
threShold=1E-2,
startTime=0.3);
Modelica.Blocks.Sources.RealExpression y21(y=hea2.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y22(y=hea1.staB.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass12(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y23(
y=hea2.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y24(
y=hea1.staA.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass13(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y25(
y=hea4.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y26(
y=hea3.staB.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass14(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y27(
y=hea4.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y28(
y=hea3.staA.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass15(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y29(
y=hea6.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y30(
y=hea5.staB.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass16(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y31(
y=hea6.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y32(
y=hea5.staA.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass17(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y33(
y=hea8.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y34(
y=hea7.staB.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass18(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y35(
y=hea8.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y36(
y=hea7.staA.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass19(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y37(y=hea2.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y38(y=hea5.staB.X[1]);
Buildings.Utilities.Diagnostics.AssertEquality ass20(threShold=1E-2, startTime=
0.3);
Modelica.Blocks.Sources.RealExpression y39(y=hea4.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y40(y=hea7.staA.X[1]);
protected
model Humidifier
"Model for humidifier that adds a variable for the thermodynamic states at its ports"
extends Buildings.Fluid.MassExchangers.Humidifier_u;
Medium.ThermodynamicState staA=
Medium.setState_phX(port_a.p,
actualStream(port_a.h_outflow),
actualStream(port_a.Xi_outflow))
"Thermodynamic state in port a";
Medium.ThermodynamicState staB=
Medium.setState_phX(port_b.p,
actualStream(port_b.h_outflow),
actualStream(port_b.Xi_outflow))
"Thermodynamic state in port b";
end Humidifier;
equation
connect(POut.y,sin_1. p_in);
connect(TDb.y,sou_1. T_in);
connect(res_11.port_b, hea1.port_a);
connect(u.y, hea1.u);
connect(gain.y, hea2.u);
connect(u.y, gain.u);
connect(res_12.port_b, hea2.port_a);
connect(res_2.port_b, hea3.port_a);
connect(u.y, hea3.u);
connect(gain.y, hea4.u);
connect(res_3.port_b, hea4.port_a);
connect(hea4.port_b, res_4.port_b);
connect(hea1.port_b, hea2.port_b);
connect(y1.y, ass1.u1);
connect(y2.y, ass1.u2);
connect(y3.y, ass2.u1);
connect(y4.y, ass2.u2);
connect(y5.y, ass3.u1);
connect(y6.y, ass3.u2);
connect(y7.y, ass4.u1);
connect(y8.y, ass4.u2);
connect(res_1.port_b, hea5.port_a);
connect(res_5.port_b, hea6.port_a);
connect(res_6.port_b,hea7. port_a);
connect(res_7.port_b,hea8. port_a);
connect(hea8.port_b,res_8. port_b);
connect(hea5.port_b,hea6. port_b);
connect(y9.y,ass5. u1);
connect(y10.y, ass5.u2);
connect(y11.y, ass6.u1);
connect(y12.y, ass6.u2);
connect(y13.y, ass7.u1);
connect(y14.y, ass7.u2);
connect(y15.y, ass8.u1);
connect(y16.y, ass8.u2);
connect(y17.y,ass9. u1);
connect(y18.y,ass9. u2);
connect(y19.y, ass10.u1);
connect(y20.y, ass10.u2);
connect(u.y, hea6.u);
connect(u.y, hea8.u);
connect(gain.y, hea5.u);
connect(gain.y, hea7.u);
connect(y21.y, ass11.u1);
connect(y22.y, ass11.u2);
connect(y23.y, ass12.u1);
connect(y24.y, ass12.u2);
connect(y25.y, ass13.u1);
connect(y26.y, ass13.u2);
connect(y27.y, ass14.u1);
connect(y28.y, ass14.u2);
connect(y29.y, ass15.u1);
connect(y30.y, ass15.u2);
connect(y31.y, ass16.u1);
connect(y32.y, ass16.u2);
connect(y33.y, ass17.u1);
connect(y34.y, ass17.u2);
connect(y35.y, ass18.u1);
connect(y36.y, ass18.u2);
connect(y37.y, ass19.u1);
connect(y38.y, ass19.u2);
connect(y39.y, ass20.u1);
connect(y40.y, ass20.u2);
connect(sin_1.ports[1], res_12.port_a);
connect(sin_1.ports[2], res_3.port_a);
connect(sou_1.ports[1], res_11.port_a);
connect(sou_1.ports[2], res_2.port_a);
connect(sin_1.ports[3], res_1.port_a);
connect(sin_1.ports[4], res_6.port_a);
connect(sou_1.ports[3], res_5.port_a);
connect(sou_1.ports[4], res_7.port_a);
connect(hea3.port_b, mix1.ports[1]);
connect(mix1.ports[2], res_4.port_a);
connect(hea7.port_b, mix2.ports[1]);
connect(mix2.ports[2], res_8.port_a);
end Humidifier_u;
Test model for prescribed outlet state
Information
Model that demonstrates the use of an ideal heater and an ideal cooler.
The heater model has an almost unlimited positive capacity (Q_flow_nominal = 1.0e10 Watts),
and hence its outlet temperature always reaches the set point temperatures.
The cooler model has a limited negative capacitiy (Q_flow_nominal = 1000 Watts), and hence
its outlet temperature reaches only a limited value corresponding to its
maximum negative capacity.
There is also a heater and cooler with unlimited capacity.
At t=1000 second, the flow reverses its direction.
Each flow leg has the same mass flow rate. There are three mass flow sources
as using one source only would yield a nonlinear system of equations that
needs to be solved to determine the mass flow rate distribution.
The heater and cooler models have the parameter show_T set to true
to allow inspecting the temperatures at their ports.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|
| MassFlowRate | m_flow_nominal | 0.1 | Nominal mass flow rate [kg/s] |
Modelica definition
model PrescribedOutletState
"Test model for prescribed outlet state"
extends Modelica.Icons.Example;
package Medium =
Buildings.Media.Water;
parameter Modelica.SIunits.MassFlowRate m_flow_nominal=0.1
"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=3)
"Sink";
Buildings.Fluid.Interfaces.PrescribedOutletState heaHigPow(
redeclare package Medium = Medium,
Q_flow_maxHeat=1.0e10,
m_flow_small=1E-4*
abs(m_flow_nominal),
show_T=true,
m_flow_nominal=m_flow_nominal)
"Steady-state model of the heater with high capacity";
Modelica.Blocks.Sources.TimeTable TSetHeat(table=[0,273.15 + 20.0; 120,273.15
+ 20.0; 120,273.15 + 60.0; 500,273.15 + 60.0; 500,273.15 + 30.0; 1200,273.15 + 30.0])
"Setpoint heating";
Buildings.Fluid.Interfaces.PrescribedOutletState cooLimPow(
redeclare package Medium = Medium,
Q_flow_maxCool=-1000,
m_flow_small=1E-4*
abs(m_flow_nominal),
show_T=true,
m_flow_nominal=m_flow_nominal)
"Steady-state model of the cooler with limited capacity";
Modelica.Blocks.Sources.TimeTable TSetCool(table=[0,273.15 + 20.0; 120,273.15
+ 20.0; 120,273.15 + 15.0; 500,273.15 + 15.0; 500,273.15 + 10.0; 1200,273.15 + 10.0])
"Setpoint cooling";
Buildings.Fluid.Interfaces.PrescribedOutletState heaCooUnl(
redeclare package Medium = Medium,
m_flow_small=1E-4*
abs(m_flow_nominal),
show_T=true,
m_flow_nominal=m_flow_nominal)
"Steady-state model of the heater or cooler with unlimited capacity";
Modelica.Blocks.Sources.TimeTable TSetCoolHeat(table=[0,273.15 + 20.0; 120,273.15
+ 20.0; 120,273.15 + 15.0; 500,273.15 + 15.0; 500,273.15 + 30.0; 1200,273.15
+ 30.0])
"Setpoint cooling";
Modelica.Blocks.Sources.Ramp m_flow(
height=-2*m_flow_nominal,
duration=100,
offset=m_flow_nominal,
startTime=1000)
"Mass flow rate";
Buildings.Fluid.Sources.MassFlowSource_T sou1(
redeclare package Medium = Medium,
use_m_flow_in=true,
T=293.15,
nPorts=1)
"Flow source";
Buildings.Fluid.Sources.MassFlowSource_T sou2(
redeclare package Medium = Medium,
use_m_flow_in=true,
T=293.15,
nPorts=1)
"Flow source";
Buildings.Fluid.Sources.MassFlowSource_T sou3(
redeclare package Medium = Medium,
use_m_flow_in=true,
T=293.15,
nPorts=1)
"Flow source";
equation
connect(TSetHeat.y,heaHigPow. TSet);
connect(TSetCool.y,cooLimPow. TSet);
connect(TSetCoolHeat.y,heaCooUnl. TSet);
connect(m_flow.y, sou1.m_flow_in);
connect(m_flow.y, sou2.m_flow_in);
connect(m_flow.y, sou3.m_flow_in);
connect(sou1.ports[1], heaHigPow.port_a);
connect(sou2.ports[1], cooLimPow.port_a);
connect(sou3.ports[1], heaCooUnl.port_a);
connect(heaCooUnl.port_b, sin.ports[1]);
connect(cooLimPow.port_b, sin.ports[2]);
connect(heaHigPow.port_b, sin.ports[3]);
end PrescribedOutletState;
Model that tests the reverse flow for a humidifier
Information
This model tests whether the results for a humidifer are
identical for forward flow and reverse flow.
If the results differ, then an assert is triggered.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ReverseFlowHumidifier
"Model that tests the reverse flow for a humidifier"
extends Modelica.Icons.Example;
package Medium =
Buildings.Media.Air;
Buildings.Utilities.Diagnostics.AssertEquality assTem(threShold=0.01)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Buildings.Utilities.Diagnostics.AssertEquality assEnt(threShold=0.5)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Buildings.Utilities.Diagnostics.AssertEquality assMas(threShold=1E-5)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Buildings.Fluid.MassExchangers.Humidifier_u humBac(
redeclare package Medium = Medium,
dp_nominal=0,
m_flow(start=1),
m_flow_nominal=1,
mWat_flow_nominal=0.1,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T=283.15)
"Humidifier with backward flow";
Buildings.Fluid.MassExchangers.Humidifier_u humFor(
redeclare package Medium = Medium,
dp_nominal=0,
m_flow(start=1),
m_flow_nominal=1,
mWat_flow_nominal=0.1,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T=283.15)
"Humidifier with forward flow";
Modelica.Blocks.Sources.Constant u2(k=0.01)
"Control input";
Modelica.Fluid.Sources.MassFlowSource_T source1(
redeclare package Medium = Medium,
use_m_flow_in=false,
use_T_in=false,
use_X_in=false,
T(displayUnit="K") = 323.15,
X={0.01,0.99},
nPorts=1,
m_flow=0.5)
"Fluid source";
Buildings.Fluid.Sources.FixedBoundary sink1(
redeclare package Medium = Medium,
nPorts=2)
"Fluid sink";
Sensors.SpecificEnthalpy senEnt1(
redeclare package Medium = Medium)
"Specific enthalpy sensor";
Sensors.Temperature senTem1(
redeclare package Medium = Medium)
"Temperature sensor";
Sensors.MassFraction senMas1(
redeclare package Medium = Medium)
"Mass fraction sensor";
Sensors.Temperature senTem2(
redeclare package Medium = Medium)
"Temperature sensor";
Sensors.SpecificEnthalpy senEnt2(
redeclare package Medium = Medium)
"Specific enthalpy sensor";
Sensors.MassFraction senMas2(
redeclare package Medium = Medium)
"Mass fraction sensor";
FixedResistances.FixedResistanceDpM res1(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000)
"Fixed resistance";
FixedResistances.FixedResistanceDpM res2(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000)
"Fixed resistance";
Modelica.Fluid.Sources.MassFlowSource_T source2(
redeclare package Medium = Medium,
use_m_flow_in=false,
use_T_in=false,
use_X_in=false,
T(displayUnit="K") = 323.15,
X={0.01,0.99},
nPorts=1,
m_flow=0.5)
"Fluid source";
equation
connect(u2.y, humFor.u);
connect(u2.y, humBac.u);
connect(humFor.port_b, senTem1.port);
connect(humFor.port_b, senEnt1.port);
connect(humFor.port_b, senMas1.port);
connect(humBac.port_a, senTem2.port);
connect(humBac.port_a, senEnt2.port);
connect(humBac.port_a, senMas2.port);
connect(humFor.port_b, res1.port_a);
connect(res1.port_b, sink1.ports[1]);
connect(humBac.port_a, res2.port_a);
connect(res2.port_b, sink1.ports[2]);
connect(senTem1.T, assTem.u1);
connect(senEnt1.h_out, assEnt.u1);
connect(senMas1.X, assMas.u1);
connect(senTem2.T, assTem.u2);
connect(senEnt2.h_out, assEnt.u2);
connect(senMas2.X, assMas.u2);
connect(humFor.port_a, source1.ports[1]);
connect(source2.ports[1], humBac.port_b);
end ReverseFlowHumidifier;
Model that tests the reverse flow for a mass exchanger
Information
This model tests whether the results for a mass exchanger are
identical for forward flow and reverse flow.
If the results differ, then an assert is triggered.
Note that if the latent heat transfer effectiveness is non-zero, then
the results will differ. The reason is that the maximum capacity stream
is computed using the mass flow rates at port_a1
and port_a2. For reverse flow, they are not equal if
moisture is added to the mass flow rate. Using an average mass flow rate
in computing the heat and moisture transfer would lead to identical results,
but it would introduce additional nonlinear equations that need to be solved.
Therefore, the model uses the mass flow rates at port_a1
and port_a2.
Note: This problem fails to translate in Dymola 2012 due to an error in Dymola's support
of stream connector. This bug will be corrected in future versions of Dymola.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ReverseFlowMassExchanger
"Model that tests the reverse flow for a mass exchanger"
extends Modelica.Icons.Example;
package Medium =
Buildings.Media.Air;
Buildings.Utilities.Diagnostics.AssertEquality assTem(threShold=1E-8,
startTime=0)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Buildings.Utilities.Diagnostics.AssertEquality assEnt(threShold=1E-8,
startTime=0)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Buildings.Utilities.Diagnostics.AssertEquality assMas(threShold=1E-8,
startTime=0)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Modelica.Fluid.Sources.MassFlowSource_T source2(
m_flow=1,
redeclare package Medium = Medium,
use_m_flow_in=false,
use_T_in=false,
use_X_in=false,
nPorts=1,
T(displayUnit="degC") = 303.15,
X={0.02,0.98});
Buildings.Fluid.MassExchangers.ConstantEffectiveness masExcFor(
redeclare package Medium1 = Medium,
redeclare package Medium2 = Medium,
m1_flow_nominal=1,
m2_flow_nominal=1,
dp1_nominal=0,
dp2_nominal=0,
epsL=0)
"Mass exchanger with forward flow";
Buildings.Fluid.MassExchangers.ConstantEffectiveness masExcRev(
redeclare package Medium1 = Medium,
redeclare package Medium2 = Medium,
m1_flow_nominal=1,
m2_flow_nominal=1,
dp1_nominal=0,
dp2_nominal=0,
epsL=0)
"Mass exchanger with reverse flow";
Buildings.Fluid.Sources.FixedBoundary sink2(
redeclare package Medium = Medium,
nPorts=2)
"Fluid sink";
FixedResistances.FixedResistanceDpM res3(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000)
"Fixed resistance";
FixedResistances.FixedResistanceDpM res4(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000)
"Fixed resistance";
Sensors.SpecificEnthalpy senEnt3(
redeclare package Medium = Medium);
Sensors.Temperature senTem3(
redeclare package Medium = Medium);
Sensors.MassFraction senMas3(
redeclare package Medium = Medium);
Sensors.SpecificEnthalpy senEnt4(
redeclare package Medium = Medium);
Sensors.Temperature senTem4(
redeclare package Medium = Medium);
Sensors.MassFraction senMas4(
redeclare package Medium = Medium);
Buildings.Utilities.Diagnostics.AssertEquality assTem1(threShold=1E-8,
startTime=0)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Buildings.Utilities.Diagnostics.AssertEquality assEnt1(threShold=1E-8,
startTime=0)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Buildings.Utilities.Diagnostics.AssertEquality assMas1(threShold=1E-8,
startTime=0)
"Assert to test if the outputs of the forward flow and reverse flow model are identical";
Modelica.Fluid.Sources.MassFlowSource_T source3(
m_flow=1,
redeclare package Medium = Medium,
use_m_flow_in=false,
use_T_in=false,
use_X_in=false,
X={0.01,0.99},
nPorts=1,
T(displayUnit="degC") = 293.15);
Modelica.Fluid.Sources.MassFlowSource_T source4(
m_flow=1,
redeclare package Medium = Medium,
use_m_flow_in=false,
use_T_in=false,
use_X_in=false,
nPorts=1,
T(displayUnit="degC") = 303.15,
X={0.02,0.98});
Modelica.Fluid.Sources.MassFlowSource_T source1(
m_flow=1,
redeclare package Medium = Medium,
use_m_flow_in=false,
use_T_in=false,
use_X_in=false,
X={0.01,0.99},
nPorts=1,
T(displayUnit="degC") = 293.15);
Buildings.Fluid.Sources.FixedBoundary sink1(
redeclare package Medium = Medium,
nPorts=2)
"Fluid sink";
Sensors.SpecificEnthalpy senEnt1(
redeclare package Medium = Medium);
Sensors.Temperature senTem1(
redeclare package Medium = Medium);
Sensors.MassFraction senMas1(
redeclare package Medium = Medium);
Sensors.Temperature senTem2(
redeclare package Medium = Medium);
Sensors.SpecificEnthalpy senEnt2(
redeclare package Medium = Medium);
Sensors.MassFraction senMas2(
redeclare package Medium = Medium);
FixedResistances.FixedResistanceDpM res1(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000)
"Fixed resistance";
FixedResistances.FixedResistanceDpM res2(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000)
"Fixed resistance";
equation
connect(res1.port_b, sink1.ports[1]);
connect(res2.port_b, sink1.ports[2]);
connect(senTem1.T, assTem.u1);
connect(senEnt1.h_out, assEnt.u1);
connect(senMas1.X, assMas.u1);
connect(senTem2.T, assTem.u2);
connect(senEnt2.h_out, assEnt.u2);
connect(senMas2.X, assMas.u2);
connect(masExcFor.port_b1, res1.port_a);
connect(masExcFor.port_a1, source1.ports[1]);
connect(masExcRev.port_a1, res2.port_a);
connect(source2.ports[1], masExcFor.port_a2);
connect(masExcRev.port_a1, senTem2.port);
connect(masExcRev.port_a1, senEnt2.port);
connect(masExcRev.port_a1, senMas2.port);
connect(masExcFor.port_b1, senTem1.port);
connect(masExcFor.port_b1, senEnt1.port);
connect(masExcFor.port_b1, senMas1.port);
connect(masExcFor.port_b2, res3.port_a);
connect(masExcRev.port_a2, res4.port_a);
connect(res3.port_b, sink2.ports[1]);
connect(res4.port_b, sink2.ports[2]);
connect(senTem3.T, assTem1.u1);
connect(senTem4.T, assTem1.u2);
connect(senEnt3.h_out, assEnt1.u1);
connect(senEnt4.h_out, assEnt1.u2);
connect(senMas3.X, assMas1.u1);
connect(senMas4.X, assMas1.u2);
connect(masExcFor.port_b2, senTem3.port);
connect(masExcFor.port_b2, senEnt3.port);
connect(masExcFor.port_b2, senMas3.port);
connect(masExcRev.port_a2, senTem4.port);
connect(masExcRev.port_a2, senEnt4.port);
connect(masExcRev.port_a2, senMas4.port);
connect(source3.ports[1], masExcRev.port_b1);
connect(source4.ports[1], masExcRev.port_b2);
end ReverseFlowMassExchanger;
Model for humidifier that adds a variable for the thermodynamic states at its ports
Information
Extends from Buildings.Fluid.MassExchangers.Humidifier_u (Ideal humidifier or dehumidifier with prescribed water mass flow rate addition or subtraction).
Parameters
| Type | Name | Default | Description |
|---|
| replaceable package Medium | PartialCondensingGases | Medium in the component |
| Boolean | use_T_in | false | Get the temperature from the input connector |
| Temperature | T | 293.15 | Temperature of water that is added to the fluid stream (used if use_T_in=false) [K] |
| MassFlowRate | mWat_flow_nominal | | Water mass flow rate at u=1, positive for humidification [kg/s] |
| Nominal condition |
| MassFlowRate | m_flow_nominal | | Nominal mass flow rate [kg/s] |
| Pressure | dp_nominal | | Pressure difference [Pa] |
| Initialization |
| MassFlowRate | m_flow.start | 0 | Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s] |
| Pressure | dp.start | 0 | Pressure difference between port_a and port_b [Pa] |
| Assumptions |
| Boolean | allowFlowReversal | true | = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
| Advanced |
| MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Boolean | homotopyInitialization | true | = true, use homotopy method |
| Diagnostics |
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Flow resistance |
| 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 |
| Real | deltaM | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Dynamics |
| Nominal condition |
| Time | tau | 30 | Time constant at nominal flow (if energyDynamics <> SteadyState) [s] |
| Equations |
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Formulation of energy balance |
| Dynamics | massDynamics | energyDynamics | Formulation of mass balance |
| Initialization |
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
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 | T_in | Temperature of water added to the fluid stream |
| input RealInput | u | Control input |
Modelica definition
model Humidifier
"Model for humidifier that adds a variable for the thermodynamic states at its ports"
extends Buildings.Fluid.MassExchangers.Humidifier_u;
Medium.ThermodynamicState staA=
Medium.setState_phX(port_a.p,
actualStream(port_a.h_outflow),
actualStream(port_a.Xi_outflow))
"Thermodynamic state in port a";
Medium.ThermodynamicState staB=
Medium.setState_phX(port_b.p,
actualStream(port_b.h_outflow),
actualStream(port_b.Xi_outflow))
"Thermodynamic state in port b";
end Humidifier;
Automatically generated Mon Jul 13 14:26:30 2015.
ConservationEquation
Buildings.Fluid.Interfaces.Examples.ConservationEquation
Buildings.Fluid.Interfaces.Examples.Humidifier_u.Humidifier