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.Fluids.Sensors.
Package Content
Information
This examples is a unit test for the dynamic dry bulb temperature sensor.
Modelica definition
model DryBulbTemperature
package Medium = Buildings.Media.PerfectGases.MoistAir "Medium model";
Modelica.Blocks.Sources.Ramp p(
duration=1,
offset=101325,
height=250);
Buildings.Fluids.Sources.PrescribedBoundary_pTX sin(redeclare package Medium
= Medium, T=293.15);
Buildings.Fluids.Sensors.DryBulbTemperatureDynamic sen(
redeclare package Medium = Medium,
T_start=Medium.T_default,
initType=Modelica.Blocks.Types.Init.SteadyState)
"Dynamic temperature sensor";
Buildings.Fluids.Sources.PrescribedMassFlowRate_pTX massFlowRate(redeclare
package Medium = Medium, m_flow=1);
Modelica.Blocks.Sources.Ramp TDB(
height=10,
duration=1,
offset=273.15 + 30) "Dry bulb temperature";
Modelica.Blocks.Sources.Ramp XHum(
height=(0.0133 - 0.0175),
offset=0.0175,
duration=60) "Humidity concentration";
Modelica.Blocks.Sources.Constant const;
Modelica.Blocks.Math.Feedback feedback;
Buildings.Utilities.Controls.AssertEquality assertEquality(startTime=0,
threShold=0.001);
Modelica.Blocks.Continuous.FirstOrder firOrd(T=10, initType=Modelica.Blocks.
Types.Init.SteadyState);
Modelica_Fluid.Sensors.Temperature temSteSta(redeclare package Medium =
Medium) "Steady state temperature sensor";
equation
connect(sen.port_b, sin.port);
connect(TDB.y, massFlowRate.T_in);
connect(const.y, feedback.u1);
connect(XHum.y, feedback.u2);
connect(XHum.y, massFlowRate.X_in[1]);
connect(feedback.y, massFlowRate.X_in[2]);
connect(p.y, sin.p_in);
connect(sen.T, assertEquality.u1);
connect(firOrd.y, assertEquality.u2);
connect(massFlowRate.port, temSteSta.port_a);
connect(temSteSta.port_b, sen.port_a);
connect(temSteSta.T, firOrd.u);
end DryBulbTemperature;
Parameters
| Type | Name | Default | Description |
|---|
| replaceable package Medium | Buildings.Media.GasesPTDecou... | |
Connectors
| Type | Name | Description |
|---|
| replaceable package Medium | |
Modelica definition
model ExtraProperty
import Buildings;
package Medium = Buildings.Media.GasesPTDecoupled.SimpleAir(extraPropertiesNames={"CO2"});
// package Medium = Buildings.Media.GasesPTDecoupled.SimpleAir;
MixingVolumes.MixingVolume vol(
redeclare package Medium = Medium,
initType=Modelica_Fluid.Types.Init.InitialValues,
nP=4,
V=2*3*3) "Mixing volume";
inner Modelica_Fluid.Ambient ambient;
Sources.PrescribedExtraPropertyFlowRate sou(redeclare package Medium = Medium);
Modelica.Blocks.Sources.Constant step(k=8.18E-6);
Buildings.Fluids.Sensors.ExtraPropertyOnePort senVol(
redeclare package Medium = Medium) "Sensor at volume";
Buildings.Fluids.Sensors.ExtraPropertyOnePort senSou(
redeclare package Medium = Medium, substanceName="CO2")
"Sensor at source";
Modelica.Blocks.Sources.Constant m_flow(k=15*1.2/3600) "Fresh air flow rate";
Sources.PrescribedMassFlowRate_phX mSou(redeclare package Medium = Medium, h=
293.15);
Modelica.Blocks.Math.Gain gain(k=-1);
Sources.PrescribedMassFlowRate_phX mSin(redeclare package Medium = Medium, h=
293.15);
Conversions.MassFractionVolumeFraction masFraSou(MMMea=Modelica.Media.
IdealGases.Common.SingleGasesData.CO2.MM);
Conversions.MassFractionVolumeFraction masFraVol(MMMea=Modelica.Media.
IdealGases.Common.SingleGasesData.CO2.MM);
RelativePressure dp(redeclare package Medium = Medium);
Buildings.Utilities.Controls.AssertEquality assertEquality(startTime=0,
threShold=1E-8);
Modelica.Blocks.Sources.Constant zer(k=0) "Zero signal";
Buildings.Fluids.Sensors.Pressure preSen(redeclare package Medium = Medium)
"Pressure sensor";
equation
connect(sou.port, vol.port[1]);
connect(step.y, sou.mC_flow_in[1]);
connect(sou.port, senSou.port);
connect(vol.port[2], senVol.port);
connect(m_flow.y, mSou.m_flow_in);
connect(mSou.port, vol.port[3]);
connect(m_flow.y, gain.u);
connect(gain.y, mSin.m_flow_in);
connect(mSin.port, vol.port[4]);
connect(senSou.C, masFraSou.m);
connect(senVol.C, masFraVol.m);
connect(mSou.port, dp.port_a);
connect(mSin.port, dp.port_b);
connect(dp.p_rel, assertEquality.u1);
connect(zer.y, assertEquality.u2);
connect(preSen.port, sou.port);
end ExtraProperty;
Information
This examples is a unit test for the wet bulb sensor.
The problem setup is such that the moisture concentration and
the dry bulb temperature are varied simultaneously in such a way
that the wet bulb temperature is constant.
This wet bulb temperature is checked against a constant value with
an assert statement.
In case this assert is triggered, then either the wet bulb sensor or
the medium model got broken (assuming that the inputs remained unchanged).
Modelica definition
model WetBulbTemperature
package Medium = Buildings.Media.PerfectGases.MoistAir "Medium model";
Modelica.Blocks.Sources.Ramp p(
duration=1,
offset=101325,
height=250);
Buildings.Fluids.Sources.PrescribedBoundary_pTX sin(redeclare package Medium
= Medium, T=293.15);
Buildings.Fluids.Sensors.WetBulbTemperature senWetBul(redeclare package
Medium = Medium) "Wet bulb temperature sensor";
Buildings.Fluids.Sources.PrescribedMassFlowRate_pTX massFlowRate(redeclare
package Medium = Medium, m_flow=1);
Modelica.Blocks.Sources.Ramp TDB(
height=10,
duration=1,
offset=273.15 + 30) "Dry bulb temperature";
Modelica.Blocks.Sources.Ramp XHum(
duration=1,
height=(0.0133 - 0.0175),
offset=0.0175) "Humidity concentration";
Modelica.Blocks.Sources.Constant const;
Modelica.Blocks.Math.Feedback feedback;
Buildings.Utilities.Controls.AssertEquality assertEquality(threShold=0.05);
Modelica.Blocks.Sources.Constant TWBExp(k=273.15 + 25)
"Expected wet bulb temperature";
equation
connect(senWetBul.port_b, sin.port);
connect(massFlowRate.port, senWetBul.port_a);
connect(TDB.y, massFlowRate.T_in);
connect(const.y, feedback.u1);
connect(XHum.y, feedback.u2);
connect(XHum.y, massFlowRate.X_in[1]);
connect(feedback.y, massFlowRate.X_in[2]);
connect(senWetBul.TWB, assertEquality.u1);
connect(TWBExp.y, assertEquality.u2);
connect(p.y, sin.p_in);
end WetBulbTemperature;
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