Buildings.Fluid.Interfaces.Examples
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
| Name | Description |
|---|---|
 ConservationEquation
|
Model that tests the conservation equation |
| FourPortHeatMassExchanger
|
FourPortHeatMassExchanger example model |
| HeaterCooler_u
|
Model that tests a heat exchanger model with reverse flow |
| Humidifier_u
|
|
| PrescribedOutletState
|
Test model for prescribed outlet state |
| ReverseFlowHumidifier
|
Model that tests the reverse flow for a humidifier |
| ReverseFlowMassExchanger
|
Model that tests the reverse flow for a mass exchanger |
| StaticTwoPortConservationEquation
|
Model that tests the static two port conservation equation |
Buildings.Fluid.Interfaces.Examples.ConservationEquation
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,
use_mWat_flow=true) "Dynamic conservation equation";
Buildings.Fluid.Interfaces.StaticTwoPortConservationEquation ste(
redeclare package Medium = Medium,
m_flow_nominal=0.01,
show_T=true,
use_mWat_flow=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.PressureDrop 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.PressureDrop 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;
Buildings.Fluid.Interfaces.Examples.FourPortHeatMassExchanger
FourPortHeatMassExchanger example model
Information
This example model demonstrates the used of the FourPortHeatMassExchanger model.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| MassFlowRate | m_flow_nominal | 1 | Nominal mass flow rate [kg/s] |
Modelica definition
model FourPortHeatMassExchanger
"FourPortHeatMassExchanger example model"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Water;
parameter Modelica.SIunits.MassFlowRate m_flow_nominal=1
"Nominal mass flow rate";
Buildings.Fluid.Interfaces.FourPortHeatMassExchanger fouPor(
redeclare package Medium1 = Medium,
redeclare package Medium2 = Medium,
m1_flow_nominal=m_flow_nominal,
m2_flow_nominal=m_flow_nominal,
dp1_nominal=0,
dp2_nominal=0,
tau1=1,
tau2=1,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Four port heat mass exchanger";
Sources.Boundary_pT sin(nPorts=2, redeclare package Medium = Medium)
"Mass flow sink";
Sources.MassFlowSource_T sou1(
nPorts=1,
redeclare package Medium = Medium,
use_m_flow_in=true,
use_T_in=true) "Mass flow source";
Sources.MassFlowSource_T sou2(
nPorts=1,
redeclare package Medium = Medium,
m_flow=1,
T=283.15) "Mass flow source";
Modelica.Blocks.Sources.Ramp ram_T(
height=10,
offset=273.15,
duration=5) "Temperature ramp";
Modelica.Blocks.Sources.Ramp ram_m_flow(
height=-2,
offset=1,
duration=5) "Mass flow rate ramp";
equation
connect(sin.ports[1], fouPor.port_b2);
connect(fouPor.port_b1, sin.ports[2]);
connect(sou1.ports[1], fouPor.port_a1);
connect(sou2.ports[1], fouPor.port_a2);
connect(ram_m_flow.y, sou1.m_flow_in);
connect(ram_T.y, sou1.T_in);
end FourPortHeatMassExchanger;
Buildings.Fluid.Interfaces.Examples.HeaterCooler_u
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 computes differences in results that are expected to be close to each other after the initial transients decayed. 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.PressureDrop res_11(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.PressureDrop 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.PressureDrop res_2(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.PressureDrop 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.PressureDrop 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);
Modelica.Blocks.Math.Add che1(k2=-1);
Modelica.Blocks.Math.Add che2(k2=-1);
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.PressureDrop res_1(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.PressureDrop 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.PressureDrop res_6(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.PressureDrop 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.PressureDrop 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);
Modelica.Blocks.Math.Add che9(k2=-1);
Modelica.Blocks.Math.Add che10(k2=-1);
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";
Modelica.Blocks.Math.Add che3(k2=-1);
Modelica.Blocks.Math.Add che4(k2=-1);
Modelica.Blocks.Math.Add che5(k2=-1);
Modelica.Blocks.Math.Add che6(k2=-1);
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";
Modelica.Blocks.Math.Add che7(k2=-1);
Modelica.Blocks.Math.Add che8(k2=-1);
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,che1. u1);
connect(senTem2a.T,che1. u2);
connect(senTem1b.T,che2. u2);
connect(senTem2b.T,che2. u1);
connect(senTem4a.T,che4. u2);
connect(senTem3a.T,che4. u1);
connect(senTem4b.T,che3. u1);
connect(senTem3b.T,che3. u2);
connect(senTem6a.T,che6. u2);
connect(senTem5a.T,che6. u1);
connect(senTem6b.T,che5. u1);
connect(senTem5b.T,che5. u2);
connect(senTem8a.T,che8. u2);
connect(senTem7a.T,che8. u1);
connect(senTem8b.T,che7. u1);
connect(senTem7b.T,che7. u2);
connect(senTem3a.T,che10. u1);
connect(senTem7a.T,che10. u2);
connect(senTem2b.T,che9. u1);
connect(senTem5b.T,che9. 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;
Buildings.Fluid.Interfaces.Examples.Humidifier_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 computes differences of results that are expected to be close to each other after the initial transients decayed.
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.PressureDrop res_11(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.PressureDrop 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.PressureDrop res_2(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.PressureDrop 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.PressureDrop 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);
Modelica.Blocks.Math.Add che1(k2=-1);
Modelica.Blocks.Sources.RealExpression y1(y=hea2.staB.T);
Modelica.Blocks.Sources.RealExpression y2(y=hea1.staB.T);
Modelica.Blocks.Math.Add che2(k2=-1);
Modelica.Blocks.Sources.RealExpression y3(y=hea2.staA.T);
Modelica.Blocks.Sources.RealExpression y4(y=hea1.staA.T);
Modelica.Blocks.Math.Add che3(k2=-1);
Modelica.Blocks.Sources.RealExpression y5(y=hea4.staB.T);
Modelica.Blocks.Sources.RealExpression y6(y=hea3.staB.T);
Modelica.Blocks.Math.Add che4(k2=-1);
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.PressureDrop res_1(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.PressureDrop 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.PressureDrop res_6(
redeclare package Medium = Medium,
dp_nominal=5,
m_flow_nominal=0.5);
Buildings.Fluid.FixedResistances.PressureDrop 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.PressureDrop 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);
Modelica.Blocks.Math.Add che5(k2=-1);
Modelica.Blocks.Sources.RealExpression y9(y=hea6.staB.T);
Modelica.Blocks.Sources.RealExpression y10(
y=hea5.staB.T);
Modelica.Blocks.Math.Add che6(k2=-1);
Modelica.Blocks.Sources.RealExpression y11(
y=hea6.staA.T);
Modelica.Blocks.Sources.RealExpression y12(
y=hea5.staA.T);
Modelica.Blocks.Math.Add che7(k2=-1);
Modelica.Blocks.Sources.RealExpression y13(
y=hea8.staB.T);
Modelica.Blocks.Sources.RealExpression y14(
y=hea7.staB.T);
Modelica.Blocks.Math.Add che8(k2=-1);
Modelica.Blocks.Sources.RealExpression y15(
y=hea8.staA.T);
Modelica.Blocks.Sources.RealExpression y16(
y=hea7.staA.T);
Modelica.Blocks.Math.Add che9(k2=-1);
Modelica.Blocks.Sources.RealExpression y17(y=hea2.staB.T);
Modelica.Blocks.Sources.RealExpression y18(y=hea5.staB.T);
Modelica.Blocks.Math.Add che10(k2=-1);
Modelica.Blocks.Sources.RealExpression y19(y=hea4.staA.T);
Modelica.Blocks.Sources.RealExpression y20(y=hea7.staA.T);
Modelica.Blocks.Math.Add che11(k2=-1);
Modelica.Blocks.Sources.RealExpression y21(y=hea2.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y22(y=hea1.staB.X[1]);
Modelica.Blocks.Math.Add che12(k2=-1);
Modelica.Blocks.Sources.RealExpression y23(
y=hea2.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y24(
y=hea1.staA.X[1]);
Modelica.Blocks.Math.Add che13(k2=-1);
Modelica.Blocks.Sources.RealExpression y25(
y=hea4.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y26(
y=hea3.staB.X[1]);
Modelica.Blocks.Math.Add che14(k2=-1);
Modelica.Blocks.Sources.RealExpression y27(
y=hea4.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y28(
y=hea3.staA.X[1]);
Modelica.Blocks.Math.Add che15(k2=-1);
Modelica.Blocks.Sources.RealExpression y29(
y=hea6.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y30(
y=hea5.staB.X[1]);
Modelica.Blocks.Math.Add che16(k2=-1);
Modelica.Blocks.Sources.RealExpression y31(
y=hea6.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y32(
y=hea5.staA.X[1]);
Modelica.Blocks.Math.Add che17(k2=-1);
Modelica.Blocks.Sources.RealExpression y33(
y=hea8.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y34(
y=hea7.staB.X[1]);
Modelica.Blocks.Math.Add che18(k2=-1);
Modelica.Blocks.Sources.RealExpression y35(
y=hea8.staA.X[1]);
Modelica.Blocks.Sources.RealExpression y36(
y=hea7.staA.X[1]);
Modelica.Blocks.Math.Add che19(k2=-1);
Modelica.Blocks.Sources.RealExpression y37(y=hea2.staB.X[1]);
Modelica.Blocks.Sources.RealExpression y38(y=hea5.staB.X[1]);
Modelica.Blocks.Math.Add che20(k2=-1);
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,che1. u1);
connect(y2.y,che1. u2);
connect(y3.y,che2. u1);
connect(y4.y,che2. u2);
connect(y5.y,che3. u1);
connect(y6.y,che3. u2);
connect(y7.y,che4. u1);
connect(y8.y,che4. 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,che5. u1);
connect(y10.y,che5. u2);
connect(y11.y,che6. u1);
connect(y12.y,che6. u2);
connect(y13.y,che7. u1);
connect(y14.y,che7. u2);
connect(y15.y,che8. u1);
connect(y16.y,che8. u2);
connect(y17.y,che9. u1);
connect(y18.y,che9. u2);
connect(y19.y,che10. u1);
connect(y20.y,che10. u2);
connect(u.y, hea6.u);
connect(u.y, hea8.u);
connect(gain.y, hea5.u);
connect(gain.y, hea7.u);
connect(y21.y,che11. u1);
connect(y22.y,che11. u2);
connect(y23.y,che12. u1);
connect(y24.y,che12. u2);
connect(y25.y,che13. u1);
connect(y26.y,che13. u2);
connect(y27.y,che14. u1);
connect(y28.y,che14. u2);
connect(y29.y,che15. u1);
connect(y30.y,che15. u2);
connect(y31.y,che16. u1);
connect(y32.y,che16. u2);
connect(y33.y,che17. u1);
connect(y34.y,che17. u2);
connect(y35.y,che18. u1);
connect(y36.y,che18. u2);
connect(y37.y,che19. u1);
connect(y38.y,che19. u2);
connect(y39.y,che20. u1);
connect(y40.y,che20. 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;
Buildings.Fluid.Interfaces.Examples.PrescribedOutletState
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;
Buildings.Fluid.Interfaces.Examples.ReverseFlowHumidifier
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.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;
Modelica.Blocks.Math.Add cheTem(k2=-1)
"Check whether the outputs of the forward flow and reverse flow model are identical";
Modelica.Blocks.Math.Add cheEnt(k2=-1)
"Check whether the outputs of the forward flow and reverse flow model are identical";
Modelica.Blocks.Math.Add cheMas(k2=-1)
"Check whether 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.PressureDrop res1(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000) "Fixed resistance";
FixedResistances.PressureDrop 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,cheTem. u1);
connect(senEnt1.h_out,cheEnt. u1);
connect(senMas1.X,cheMas. u1);
connect(senTem2.T,cheTem. u2);
connect(senEnt2.h_out,cheEnt. u2);
connect(senMas2.X,cheMas. u2);
connect(humFor.port_a, source1.ports[1]);
connect(source2.ports[1], humBac.port_b);
end ReverseFlowHumidifier;
Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger
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.
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;
Modelica.Blocks.Math.Add cheTem(k2=-1)
"Check whether the outputs of the forward flow and reverse flow model are identical";
Modelica.Blocks.Math.Add cheEnt(k2=-1)
"Check whether the outputs of the forward flow and reverse flow model are identical";
Modelica.Blocks.Math.Add cheMas(k2=-1)
"Check whether 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.PressureDrop res3(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000) "Fixed resistance";
FixedResistances.PressureDrop 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);
Modelica.Blocks.Math.Add cheTem1(k2=-1)
"Check whether the outputs of the forward flow and reverse flow model are identical";
Modelica.Blocks.Math.Add cheEnt1(k2=-1)
"Check whether the outputs of the forward flow and reverse flow model are identical";
Modelica.Blocks.Math.Add cheMas1(k2=-1)
"Check whether 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.PressureDrop res1(
redeclare package Medium = Medium,
m_flow_nominal=1,
from_dp=true,
linearized=false,
dp_nominal=1000) "Fixed resistance";
FixedResistances.PressureDrop 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,cheTem. u1);
connect(senEnt1.h_out,cheEnt. u1);
connect(senMas1.X,cheMas. u1);
connect(senTem2.T,cheTem. u2);
connect(senEnt2.h_out,cheEnt. u2);
connect(senMas2.X,cheMas. 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,cheTem1. u1);
connect(senTem4.T,cheTem1. u2);
connect(senEnt3.h_out,cheEnt1. u1);
connect(senEnt4.h_out,cheEnt1. u2);
connect(senMas3.X,cheMas1. u1);
connect(senMas4.X,cheMas1. 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;
Buildings.Fluid.Interfaces.Examples.StaticTwoPortConservationEquation
Model that tests the static two port conservation equation
Information
Model that tests the conservation equations that are used for the heat and mass balance. The instances have either water or air, and either allow or prohibit flow reversal. This example tests the implementation of the steady-state balance.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model StaticTwoPortConservationEquation
"Model that tests the static two port conservation equation"
extends Modelica.Icons.Example;
package MediumW = Buildings.Media.Water "Medium model";
package MediumA = Buildings.Media.Air "Medium model";
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";
SubModel modWatRev(
redeclare package Medium = MediumW,
allowFlowReversal=true,
use_mWat_flow = false) "Submodel for energy and mass balance";
SubModel modWatNoRev(
redeclare package Medium = MediumW,
allowFlowReversal=false,
use_mWat_flow = false) "Submodel for energy and mass balance";
SubModel modAirRev(
redeclare package Medium = MediumA,
allowFlowReversal=true,
use_mWat_flow = true) "Submodel for energy and mass balance";
SubModel modAirNoRev(
redeclare package Medium = MediumA,
allowFlowReversal=false,
use_mWat_flow = true) "Submodel for energy and mass balance";
equation
connect(QSen_flow.y, modWatRev.Q_flow);
connect(mWat_flow.y, modWatRev.mWat_flow);
protected
model SubModel
replaceable package Medium = Modelica.Media.Interfaces.PartialMedium
"Medium model";
Sources.MassFlowSource_T bou(
nPorts=1,
redeclare package Medium = Medium,
m_flow=0.01) "Boundary condition for mass flow rate";
Buildings.Fluid.Interfaces.StaticTwoPortConservationEquation conEqn(
redeclare package Medium = Medium,
m_flow_nominal=0.01,
show_T=true,
allowFlowReversal=allowFlowReversal,
use_mWat_flow=use_mWat_flow,
prescribedHeatFlowRate=true) "Steady-state conservation equation";
Buildings.Fluid.Sources.Boundary_pT sin(
use_p_in=false,
redeclare package Medium = Medium,
nPorts=1,
p=101325,
T=283.15) "Sink";
Modelica.Blocks.Interfaces.RealInput Q_flow(unit="W");
Modelica.Blocks.Interfaces.RealInput mWat_flow(unit="kg/s");
parameter Boolean use_mWat_flow
"Set to true to enable exchange of moisture";
parameter Boolean allowFlowReversal=true
"= false to simplify equations, assuming, but not enforcing, no flow reversal";
equation
connect(conEqn.port_b, sin.ports[1]);
connect(conEqn.port_a, bou.ports[1]);
connect(Q_flow, conEqn.Q_flow);
connect(mWat_flow, conEqn.mWat_flow);
end SubModel;
equation
connect(QSen_flow.y, modWatNoRev.Q_flow);
connect(mWat_flow.y, modWatNoRev.mWat_flow);
connect(QSen_flow.y, modAirRev.Q_flow);
connect(mWat_flow.y, modAirRev.mWat_flow);
connect(QSen_flow.y, modAirNoRev.Q_flow);
connect(mWat_flow.y, modAirNoRev.mWat_flow);
end StaticTwoPortConservationEquation;
Buildings.Fluid.Interfaces.Examples.Humidifier_u.Humidifier
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] | |
| PressureDifference | dp_nominal | Pressure difference [Pa] | |
| Assumptions | |||
| Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
| 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... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| 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;
Buildings.Fluid.Interfaces.Examples.StaticTwoPortConservationEquation.SubModel
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | Modelica.Media.Interfaces.Pa... | Medium model | |
| Boolean | use_mWat_flow | Set to true to enable exchange of moisture | |
| Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package Medium | Medium model | |
| input RealInput | Q_flow | [W] |
| input RealInput | mWat_flow | [kg/s] |
Modelica definition
model SubModel
replaceable package Medium = Modelica.Media.Interfaces.PartialMedium
"Medium model";
Sources.MassFlowSource_T bou(
nPorts=1,
redeclare package Medium = Medium,
m_flow=0.01) "Boundary condition for mass flow rate";
Buildings.Fluid.Interfaces.StaticTwoPortConservationEquation conEqn(
redeclare package Medium = Medium,
m_flow_nominal=0.01,
show_T=true,
allowFlowReversal=allowFlowReversal,
use_mWat_flow=use_mWat_flow,
prescribedHeatFlowRate=true) "Steady-state conservation equation";
Buildings.Fluid.Sources.Boundary_pT sin(
use_p_in=false,
redeclare package Medium = Medium,
nPorts=1,
p=101325,
T=283.15) "Sink";
Modelica.Blocks.Interfaces.RealInput Q_flow(unit="W");
Modelica.Blocks.Interfaces.RealInput mWat_flow(unit="kg/s");
parameter Boolean use_mWat_flow
"Set to true to enable exchange of moisture";
parameter Boolean allowFlowReversal=true
"= false to simplify equations, assuming, but not enforcing, no flow reversal";
equation
connect(conEqn.port_b, sin.ports[1]);
connect(conEqn.port_a, bou.ports[1]);
connect(Q_flow, conEqn.Q_flow);
connect(mWat_flow, conEqn.mWat_flow);
end SubModel;