Buildings.Airflow.Multizone.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.Airflow.Multizone.
Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).
Package Content
| Name | Description |
|---|---|
 CO2TransportStep
|
Model with transport of CO2 through buoyancy driven flow |
| ChimneyShaftNoVolume
|
Model with chimney effect and a steady-state model of a shaft |
| ChimneyShaftWithVolume
|
Model with chimney effect and a dynamic model of a shaft |
| ClosedDoors
|
Model with three closed doors |
| NaturalVentilation
|
Model with flow reversal due to density difference |
| OneEffectiveAirLeakageArea
|
Model with an effective air leakage area |
| OneOpenDoor
|
Model with one open and one closed door |
| OneRoom
|
Model with one room for the validation of the multizone air exchange models |
| Orifice
|
Model with an orifice |
| PowerLaw
|
Model with powerlaw models |
| PressurizationData
|
Model showing how the 'Powerlaw_1DataPoint' model can be used when data is available from a pressurization test. |
| ReverseBuoyancy
|
Model with four rooms and buoyancy-driven air circulation that reverses direction |
| ReverseBuoyancy3Zones
|
Model with three rooms and buoyancy-driven air circulation that reverses direction |
| TrickleVent
|
Model with a trickle vent modelled using the models with flow based on tabulated data |
| ZonalFlow
|
Model with prescribed air exchange between two volumes |
Buildings.Airflow.Multizone.Examples.CO2TransportStep
Model with transport of CO2 through buoyancy driven flow
Information
This model is based on
Buildings.Airflow.Multizone.Validation.ThreeRoomsContam.
In addition, a CO2 source has been added to the left room
in the bottom floor.
At initial time, all volumes have zero CO2 concentration.
At t=3600 seconds, CO2 is added to volWes.
As time progresses, the CO2 is transported to
the other rooms, and eventually its concentration decays.
Extends from Buildings.Airflow.Multizone.Validation.ThreeRoomsContam (Model with three rooms for the validation of the multizone air exchange models).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| DoorOpen | dooOpeClo | redeclare DoorOpen dooOpeClo... | Door |
Modelica definition
model CO2TransportStep "Model with transport of CO2 through buoyancy driven flow"
extends Buildings.Airflow.Multizone.Validation.ThreeRoomsContam(
volWes(nPorts=5),
volTop(nPorts=3),
volEas(nPorts=6));
Buildings.Fluid.Sensors.TraceSubstances CO2SenTop(
redeclare package Medium = Medium,
warnAboutOnePortConnection = false)
"CO2 sensor";
Buildings.Fluid.Sensors.TraceSubstances CO2SenWes(
redeclare package Medium = Medium,
warnAboutOnePortConnection = false)
"CO2 sensor";
Buildings.Fluid.Sensors.TraceSubstances CO2SenEas(
redeclare package Medium = Medium,
warnAboutOnePortConnection = false)
"CO2 sensor";
Modelica.Blocks.Sources.Pulse pulse(
amplitude=8.18E-6,
width=1/24/10,
period=86400,
startTime=3600) "Pulse signal for CO2 flow source";
Buildings.Fluid.Sources.TraceSubstancesFlowSource sou(
redeclare package Medium = Medium,
use_m_flow_in=true,
nPorts=1) "CO2 source";
equation
connect(sou.m_flow_in, pulse.y);
connect(sou.ports[1], volWes.ports[4]);
connect(CO2SenWes.port, volWes.ports[5]);
connect(CO2SenTop.port, volTop.ports[3]);
connect(CO2SenEas.port, volEas.ports[6]);
end CO2TransportStep;
Buildings.Airflow.Multizone.Examples.ChimneyShaftNoVolume
Model with chimney effect and a steady-state model of a shaft
Information
This model demonstrate buoyancy-induced air flow through a vertical shaft. On the right, there are two flow paths that are connected to a volume, which is kept at 20°C through a feedback controller, and to the ambient, which is at 0°C. The flow path on the very right consists of an orifice and two models that compute the pressure difference Δp between the bottom and top of the medium column using Δp=h ρ g, where h is the height of the medium column, ρ is the density of the medium column and g is the gravity constant.
The top model is parameterized to use the
density from the ambient,
whereas the bottom model is parameterized to use
the density from the room volume, regardless of
the flow direction.
In the other flow path, the model sha
is parameterized to use the density of the inflowing
medium.
Thus, these models can be thought of as a chimney to the left,
and a roof with a leakage on the right. The chimney height starts
1.5 m below the roof, and ends 1.5 m above the roof.
The flow boundary condition of the model
boundary is such that at the start
of the simulation, air flows from boundary
to roo until t=600 seconds. Then, the flow rate
is set to zero until t=1800 seconds.
Since the shaft sha is filled with
20°C air, there is a circulation in the clock-wise
direction; up the shaft, and down the other flow path.
Next, until t=2400 seconds, air is extracted from
the volume roo, and then the flow rate
of boundary is set to zero. Since the
shaft sha is now filed with air at 0°C,
there is a counter clock-wise flow; down the shaft, and
up the other flow path.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ChimneyShaftNoVolume
"Model with chimney effect and a steady-state model of a shaft"
extends Modelica.Icons.Example;
package Medium = Modelica.Media.Air.SimpleAir;
Buildings.Fluid.MixingVolumes.MixingVolume roo(
V=2.5*5*5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T_start=273.15 + 20,
redeclare package Medium = Medium,
m_flow_nominal=0.05,
p_start=101325,
nPorts=3) "Air volume of a room";
Buildings.Airflow.Multizone.Orifice oriChiTop(
m=0.5,
redeclare package Medium = Medium,
A=0.01) "Orifice at top";
Buildings.Fluid.Sources.MassFlowSource_T boundary(
redeclare package Medium = Medium,
use_m_flow_in=true,
T=293.15,
nPorts=1) "Mass flow rate boundary condition";
Buildings.Fluid.Sources.Boundary_pT bou0(
redeclare package Medium = Medium,
T=273.15,
nPorts=2) "Pressure boundary condition";
Buildings.Airflow.Multizone.Orifice oriBot(
m=0.5,
redeclare package Medium = Medium,
A=0.01) "Orifice";
Modelica.Blocks.Sources.CombiTimeTable mRoo_flow(tableOnFile=false, table=[0,
0.05; 600,0.05; 601,0; 1800,0; 1801,-0.05; 2400,-0.05; 2401,0; 3600,0])
"Mass flow into and out of room to fill the medium column with air of different temperature";
MediumColumn staOut(
redeclare package Medium = Medium,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop,
h=1.5) "Model for stack effect outside the room";
Buildings.Airflow.Multizone.Orifice oriChiBot(
m=0.5,
redeclare package Medium = Medium,
A=0.01) "Orifice at bottom";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow preHea
"Prescribed heat flow rate";
Modelica.Blocks.Continuous.LimPID con(
Td=10,
yMax=1,
yMin=-1,
Ti=60,
controllerType=Modelica.Blocks.Types.SimpleController.P,
k=5) "Controller to maintain volume temperature";
Modelica.Blocks.Sources.Constant TSet(k=293.15) "Temperature set point";
Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor temSen
"Temperature sensor";
Modelica.Blocks.Math.Gain gain(k=3000) "Gain for heat flow rate";
Buildings.Airflow.Multizone.MediumColumn sha(redeclare package Medium = Medium,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.actual) "Shaft of chimney";
MediumColumn staIn(
redeclare package Medium = Medium,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom,
h=1.5) "Model for stack effect inside the room";
equation
connect(TSet.y, con.u_s);
connect(temSen.T, con.u_m);
connect(gain.u, con.y);
connect(gain.y, preHea.Q_flow);
connect(sha.port_a, oriChiTop.port_a);
connect(sha.port_b, oriChiBot.port_b);
connect(staOut.port_b, oriBot.port_a);
connect(preHea.port, roo.heatPort);
connect(roo.heatPort, temSen.port);
connect(bou0.ports[1], oriChiTop.port_b);
connect(bou0.ports[2], staOut.port_a);
connect(oriBot.port_b, staIn.port_a);
connect(mRoo_flow.y[1], boundary.m_flow_in);
connect(boundary.ports[1], roo.ports[1]);
connect(roo.ports[2], staIn.port_b);
connect(roo.ports[3], oriChiBot.port_a);
end ChimneyShaftNoVolume;
Buildings.Airflow.Multizone.Examples.ChimneyShaftWithVolume
Model with chimney effect and a dynamic model of a shaft
Information
This model is identical to
Buildings.Airflow.Multizone.Examples.ChimneyShaftNoVolume,
except that the chimney model is not steady-state, but rather dynamic
as it contains an air volume. The air volume is approximated
as being well-mixed. (Stratified volumes could be approximated by
using multiple instances of the model sha that are
connected in series.)
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ChimneyShaftWithVolume
"Model with chimney effect and a dynamic model of a shaft"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
Buildings.Fluid.MixingVolumes.MixingVolume roo(
V=2.5*5*5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T_start=273.15 + 20,
redeclare package Medium = Medium,
m_flow_nominal=0.05,
p_start=101325,
nPorts=3) "Air volume of a room";
Buildings.Airflow.Multizone.Orifice oriChiTop(
m=0.5,
redeclare package Medium = Medium,
A=0.01) "Orifice at top";
Buildings.Fluid.Sources.MassFlowSource_T boundary(
redeclare package Medium = Medium,
use_m_flow_in=true,
T=293.15,
nPorts=1) "Mass flow rate boundary condition";
Buildings.Fluid.Sources.Boundary_pT bou0(
redeclare package Medium = Medium,
T=273.15,
nPorts=2) "Pressure boundary condition";
Buildings.Airflow.Multizone.Orifice oriBot(
m=0.5,
redeclare package Medium = Medium,
A=0.01) "Orifice";
Modelica.Blocks.Sources.CombiTimeTable mRoo_flow(tableOnFile=false, table=[0,
0.05; 600,0.05; 601,0; 1800,0; 1801,-0.05; 2400,-0.05; 2401,0; 3600,0])
"Mass flow into and out of room to fill the medium column with air of different temperature";
MediumColumn staOut(
redeclare package Medium = Medium,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop,
h=1.5) "Model for stack effect outside the room";
Buildings.Airflow.Multizone.Orifice oriChiBot(
m=0.5,
redeclare package Medium = Medium,
A=0.01) "Orifice at bottom";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow preHea
"Prescribed heat flow";
Modelica.Blocks.Continuous.LimPID con(
Td=10,
yMax=1,
yMin=-1,
Ti=60,
controllerType=Modelica.Blocks.Types.SimpleController.P,
k=5) "Controller to maintain volume temperature";
Modelica.Blocks.Sources.Constant TSet(k=293.15) "Temperature set point";
Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor temSen
"Temperature sensor";
Modelica.Blocks.Math.Gain gain(k=3000) "Gain for heat flow rate";
Buildings.Airflow.Multizone.MediumColumnDynamic sha(
redeclare package Medium = Medium,
V=3,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
"Shaft of chimney";
MediumColumn staIn(
redeclare package Medium = Medium,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom,
h=1.5) "Model for stack effect inside the room";
equation
connect(TSet.y, con.u_s);
connect(temSen.T, con.u_m);
connect(gain.u, con.y);
connect(gain.y, preHea.Q_flow);
connect(sha.port_a, oriChiTop.port_a);
connect(sha.port_b, oriChiBot.port_b);
connect(staOut.port_b, oriBot.port_a);
connect(preHea.port, roo.heatPort);
connect(roo.heatPort, temSen.port);
connect(bou0.ports[1], oriChiTop.port_b);
connect(bou0.ports[2], staOut.port_a);
connect(oriBot.port_b, staIn.port_a);
connect(mRoo_flow.y[1], boundary.m_flow_in);
connect(boundary.ports[1], roo.ports[1]);
connect(roo.ports[2], staIn.port_b);
connect(roo.ports[3], oriChiBot.port_a);
end ChimneyShaftWithVolume;
Buildings.Airflow.Multizone.Examples.ClosedDoors
Model with three closed doors
Information
This model consists of three volumes that are connected among
each other through three doors that all have the same geometry.
All doors are closed, but they are not air-tight.
Heat is added and removed from volB which induces
a small air flow through the doors.
This model uses Buildings.Media.Specialized.Air.PerfectGas as the medium because Buildings.Media.Air does not account for expansion if air the air is heated.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ClosedDoors "Model with three closed doors"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Specialized.Air.PerfectGas;
Buildings.Airflow.Multizone.DoorDiscretizedOperable dooAB(
redeclare package Medium = Medium,
LClo=20*1E-4,
forceErrorControlOnFlow=true) "Discretized door";
Buildings.Fluid.MixingVolumes.MixingVolume volA(
redeclare package Medium = Medium,
V=2.5*5*5,
nPorts=4,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
m_flow_nominal=0.01) "Control volume";
Buildings.Fluid.MixingVolumes.MixingVolume volB(
redeclare package Medium = Medium,
V=2.5*5*5,
nPorts=4,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
m_flow_nominal=0.01) "Control volume";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow preHeaFlo
"Prescribed heat flow rate boundary condition";
Modelica.Blocks.Sources.Sine sinBou(f=1/3600)
"Signal for heat flow rate boundary condition";
Modelica.Blocks.Math.Gain gai(k=100) "Gain for heat flow boundary condition";
Buildings.Fluid.MixingVolumes.MixingVolume volC(
redeclare package Medium = Medium,
V=2.5*5*5,
nPorts=4,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
m_flow_nominal=0.01) "Control volume";
Buildings.Airflow.Multizone.DoorDiscretizedOperable dooAC(
redeclare package Medium = Medium,
LClo=20*1E-4,
forceErrorControlOnFlow=true) "Discretized door";
Modelica.Blocks.Sources.Constant yDoor(k=0) "Input signal for door opening";
Buildings.Airflow.Multizone.DoorDiscretizedOperable dooBC(
redeclare package Medium = Medium,
LClo=20*1E-4,
forceErrorControlOnFlow=true) "Discretized door";
equation
connect(gai.y, preHeaFlo.Q_flow);
connect(sinBou.y, gai.u);
connect(yDoor.y, dooAB.y);
connect(yDoor.y, dooAC.y);
connect(yDoor.y, dooBC.y);
connect(preHeaFlo.port, volB.heatPort);
connect(volC.ports[1], dooAC.port_b1);
connect(volC.ports[2], dooAC.port_a2);
connect(volC.ports[3], dooBC.port_b1);
connect(volC.ports[4], dooBC.port_a2);
connect(volB.ports[1], dooAB.port_b1);
connect(volB.ports[2], dooAB.port_a2);
connect(volB.ports[3], dooBC.port_a1);
connect(volB.ports[4], dooBC.port_b2);
connect(volA.ports[1], dooAC.port_b2);
connect(volA.ports[2], dooAC.port_a1);
connect(volA.ports[3], dooAB.port_b2);
connect(volA.ports[4], dooAB.port_a1);
end ClosedDoors;
Buildings.Airflow.Multizone.Examples.NaturalVentilation
Model with flow reversal due to density difference
Information
This model illustrates buoyancy-driven natural ventilation between
two volumes of air.
The volume volA can be considered as the volume of a room,
and the volume volOut is parameterized to be very large to emulate
outside air.
The outside air is 20°C and at initial time, the room air is
18°C.
This induces an airflow in counter clock-wise direction. Since
heat is added to the room air volume, its temperature raises above the temperature of the outside, which causes the air flow to reverse its direction.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model NaturalVentilation
"Model with flow reversal due to density difference"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
Buildings.Fluid.MixingVolumes.MixingVolume volA(
redeclare package Medium = Medium,
V=2.5*10*5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T_start=273.15 + 18,
nPorts=2,
m_flow_nominal=0.001) "Control volume";
Buildings.Airflow.Multizone.Orifice oriOutBot(
redeclare package Medium = Medium,
A=0.1,
m=0.5,
dp_turbulent=0.1) "Orifice";
Buildings.Airflow.Multizone.MediumColumn colOut(
redeclare package Medium = Medium,
h=3,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.Orifice oriOutTop(
redeclare package Medium = Medium,
A=0.1,
m=0.5,
dp_turbulent=0.1) "Orifice";
Buildings.Airflow.Multizone.MediumColumn colRooTop(
redeclare package Medium = Medium,
h=3,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Fluid.MixingVolumes.MixingVolume volOut(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
V=1E10,
T_start=273.15 + 20,
nPorts=2,
m_flow_nominal=0.001) "Control volume";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow preHeaFlo
"Prescribed heat flow rate boundary condition";
Modelica.Blocks.Sources.Step q_flow(
height=-100,
offset=100,
startTime=3600) "Step function for heat flow boundary condition";
equation
connect(q_flow.y, preHeaFlo.Q_flow);
connect(oriOutBot.port_b, volOut.ports[1]);
connect(preHeaFlo.port, volA.heatPort);
connect(volA.ports[1], oriOutBot.port_a);
connect(volA.ports[2], colRooTop.port_b);
connect(colRooTop.port_a, oriOutTop.port_a);
connect(volOut.ports[2], colOut.port_b);
connect(colOut.port_a, oriOutTop.port_b);
end NaturalVentilation;
Buildings.Airflow.Multizone.Examples.OneEffectiveAirLeakageArea
Model with an effective air leakage area
Information
This model consists of a model for an effective air leakage area
that is connected to two air volumes.
Air flows due to the addition of air to the volume volA
and because heat is exchanged with volB.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model OneEffectiveAirLeakageArea "Model with an effective air leakage area"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
Buildings.Fluid.MixingVolumes.MixingVolume volA(
redeclare package Medium = Medium,
V=2.5*5*5,
nPorts=2,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
m_flow_nominal=0.01) "Control volume";
Buildings.Fluid.MixingVolumes.MixingVolume volB(
redeclare package Medium = Medium,
V=2.5*5*5,
nPorts=1,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
m_flow_nominal=0.01) "Control volume";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow preHeaFlo
"Prescribed heat flow rate boundary condition";
Modelica.Blocks.Sources.Sine heaFloBou(f=1/3600)
"Signal for heat flow rate boundary condition";
Modelica.Blocks.Math.Gain gai(k=100)
"Gain for heat flow rate boundary condition";
Buildings.Airflow.Multizone.EffectiveAirLeakageArea cra(redeclare package
Medium = Medium, L=20E-4)
"Crack model, parameterized with effective leakage area";
Buildings.Fluid.Sources.MassFlowSource_T sou(
redeclare package Medium = Medium,
nPorts=1,
use_m_flow_in=true) "Prescribed mass flow rate boundary condition";
Modelica.Blocks.Sources.Ramp ramSou(
duration=3600,
height=0.01,
offset=0,
startTime=1800)
"Ramp signal for prescribed mass flow rate boundary condition";
equation
connect(sou.ports[1], volA.ports[1]);
connect(ramSou.y, sou.m_flow_in);
connect(volB.ports[1], cra.port_b);
connect(volA.ports[2], cra.port_a);
connect(preHeaFlo.port, volB.heatPort);
connect(gai.y, preHeaFlo.Q_flow);
connect(gai.u, heaFloBou.y);
end OneEffectiveAirLeakageArea;
Buildings.Airflow.Multizone.Examples.OneOpenDoor
Model with one open and one closed door
Information
This model consists of two doors with the same geometry.
For t ≤ 1000 seconds, the door dooOpeClo
is closed, and afterwards it is open. The door
dooOpe is always open.
Heat is added to the volume volB, which causes
a density difference between volA and volB.
This density difference induces a bi-directional airflow through both doors.
Both doors have exactly the same bi-directional airflow rates.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model OneOpenDoor "Model with one open and one closed door"
extends Modelica.Icons.Example;
package Medium = Modelica.Media.Air.SimpleAir;
Buildings.Airflow.Multizone.DoorDiscretizedOpen dooOpe(
redeclare package Medium = Medium) "Discretized door";
Buildings.Fluid.MixingVolumes.MixingVolume volA(
redeclare package Medium = Medium,
V=2.5*5*5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
nPorts=4,
m_flow_nominal=0.01) "Control volume";
Buildings.Fluid.MixingVolumes.MixingVolume volB(
redeclare package Medium = Medium,
V=2.5*5*5,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
nPorts=4,
m_flow_nominal=0.01) "Control volume";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow preHeaFlo
"Prescribed heat flow rate boundary condition";
Modelica.Blocks.Sources.Sine heaSou(f=1/3600)
"Signal for heat flow rate boundary condition";
Modelica.Blocks.Math.Gain gai(k=100)
"Gain for heat flow rate boundary condition";
Buildings.Airflow.Multizone.DoorDiscretizedOperable dooOpeClo(redeclare
package
Medium = Medium, LClo=20*1E-4) "Discretized door";
Modelica.Blocks.Sources.Ramp ramp(
duration=120,
height=1,
offset=0,
startTime=1000) "Ramp signal for door opening";
equation
connect(gai.y, preHeaFlo.Q_flow);
connect(heaSou.y, gai.u);
connect(ramp.y, dooOpeClo.y);
connect(preHeaFlo.port, volB.heatPort);
connect(volA.ports[1], dooOpeClo.port_b2);
connect(volA.ports[2], dooOpeClo.port_a1);
connect(volA.ports[3], dooOpe.port_b2);
connect(volA.ports[4], dooOpe.port_a1);
connect(volB.ports[1], dooOpe.port_b1);
connect(volB.ports[2], dooOpe.port_a2);
connect(volB.ports[3], dooOpeClo.port_b1);
connect(volB.ports[4], dooOpeClo.port_a2);
end OneOpenDoor;
Buildings.Airflow.Multizone.Examples.OneRoom
Model with one room for the validation of the multizone air exchange models
Information
This model has been used to validate buoyancy-driven air flow between two volumes.
The volume volEas is at 20°C and the volume
volOut is at 10°C.
This initial condition induces a clock-wise airflow between the two volumes.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model OneRoom
"Model with one room for the validation of the multizone air exchange models"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
Buildings.Fluid.MixingVolumes.MixingVolume volEas(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T_start=273.15 + 20,
V=2.5*5*5,
nPorts=2,
m_flow_nominal=0.001,
massDynamics=Modelica.Fluid.Types.Dynamics.SteadyStateInitial)
"Control volume for room";
Buildings.Airflow.Multizone.Orifice oriOutBot(
redeclare package Medium = Medium,
A=0.01,
m=0.5) "Orifice at bottom";
Buildings.Airflow.Multizone.MediumColumn colOutTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.Orifice oriOutTop(
redeclare package Medium = Medium,
A=0.01,
m=0.5) "Orifice at top";
Buildings.Airflow.Multizone.MediumColumn colEasInTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Fluid.MixingVolumes.MixingVolume volOut(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T_start=273.15 + 10,
V=1E12,
p_start=Medium.p_default,
nPorts=2,
m_flow_nominal=0.001)
"Control volume for outside";
Buildings.Airflow.Multizone.MediumColumn colEasInBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.MediumColumn colOutBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
equation
connect(colEasInTop.port_a, oriOutTop.port_a);
connect(colEasInTop.port_b, volEas.ports[1]);
connect(colEasInBot.port_a, volEas.ports[2]);
connect(colEasInBot.port_b, oriOutBot.port_a);
connect(oriOutBot.port_b, colOutBot.port_b);
connect(colOutBot.port_a, volOut.ports[1]);
connect(colOutTop.port_b, volOut.ports[2]);
connect(colOutTop.port_a, oriOutTop.port_b);
end OneRoom;
Buildings.Airflow.Multizone.Examples.Orifice
Model with an orifice
Information
This model demonstrates the use of the orifice model. The pressure difference across the orifice model changes between -1 Pascal and +1 Pascal, which causes air to flow through the orifice.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model Orifice "Model with an orifice"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
Buildings.Airflow.Multizone.Orifice ori(redeclare package Medium = Medium, A=
0.2) "Orifice";
Buildings.Fluid.Sources.Boundary_pT roo1(
redeclare package Medium = Medium,
use_p_in=true,
nPorts=1,
T=278.15) "Pressure boundary condition";
Buildings.Fluid.Sources.Boundary_pT roo2(
redeclare package Medium = Medium,
use_p_in=true,
nPorts=1,
T=293.15) "Pressure boundary condition";
Modelica.Blocks.Sources.Ramp ram(
duration=0.5,
height=2,
offset=-1,
startTime=0.25) "Ramp signal for pressure boundary condition";
Modelica.Blocks.Sources.Constant preBou(k=100000)
"Constant pressure boundary condition";
Modelica.Blocks.Math.Add add "Adder for pressure boundary condition";
Buildings.Fluid.Sensors.DensityTwoPort den1(
redeclare package Medium = Medium,
m_flow_nominal=0.1,
initType=Modelica.Blocks.Types.Init.InitialState) "Density sensor";
Buildings.Fluid.Sensors.DensityTwoPort den2(
redeclare package Medium = Medium,
m_flow_nominal=0.1,
initType=Modelica.Blocks.Types.Init.InitialState) "Density sensor";
equation
connect(preBou.y, add.u1);
connect(ram.y, add.u2);
connect(preBou.y, roo1.p_in);
connect(add.y, roo2.p_in);
connect(roo1.ports[1], den1.port_a);
connect(den1.port_b, ori.port_a);
connect(ori.port_b, den2.port_a);
connect(den2.port_b, roo2.ports[1]);
end Orifice;
Buildings.Airflow.Multizone.Examples.PowerLaw
Model with powerlaw models
Information
This model demonstrates the use of the 4 PowerLaw models present in the multizone package. The input data is fit so that all models have equivalent output. The pressure difference across the models changes between -1 Pascal and +1 Pascal, which causes air to flow through the orifice.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model PowerLaw "Model with powerlaw models"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
Coefficient_m_flow pow_m_flow(
redeclare package Medium = Medium,
m=0.59,
k=3.33e-5) "Mass flow rate based on powerlaw, direct input for m and C";
Buildings.Fluid.Sources.Boundary_pT roo1(
redeclare package Medium = Medium,
use_p_in=true,
nPorts=1,
T=278.15) "Room 1";
Buildings.Fluid.Sources.Boundary_pT roo2(
redeclare package Medium = Medium,
use_p_in=true,
nPorts=1,
T=293.15) "Room 2";
Modelica.Blocks.Sources.Ramp ramp1(
duration=0.5,
height=6,
offset=-3,
startTime=0.25) "Ramp";
Modelica.Blocks.Sources.Constant pressure(k=100000) "Pressure";
Modelica.Blocks.Math.Add add "Add";
Buildings.Fluid.Sensors.DensityTwoPort den1(
redeclare package Medium = Medium,
m_flow_nominal=0.1,
tau=0,
initType=Modelica.Blocks.Types.Init.InitialState) "Density sensor";
Buildings.Fluid.Sensors.DensityTwoPort den2(
redeclare package Medium = Medium,
m_flow_nominal=0.1,
tau=0,
initType=Modelica.Blocks.Types.Init.InitialState) "Density sensor";
Coefficient_V_flow pow_V_flow(
redeclare package Medium = Medium,
m=0.59,
C=3.33e-5/1.2)
"Volume flow rate based on powerlaw, direct input for m and C";
Point_m_flow pow_1dat(
redeclare package Medium = Medium,
dpMea_nominal = 50,
m=0.59,
mMea_flow_nominal=1.2/3600)
"Mass flow rate based on powerlaw, input of m and 1 test data point.";
Points_m_flow pow_2dat(
redeclare package Medium = Medium,
dpMea_nominal = {1, 50},
mMea_flow_nominal={0.12, 1.2}/3600)
"Mass flow rate based on powerlaw, input of 2 test data points.";
equation
connect(pressure.y, add.u1);
connect(ramp1.y, add.u2);
connect(pressure.y, roo1.p_in);
connect(add.y, roo2.p_in);
connect(roo1.ports[1], den1.port_a);
connect(den1.port_b, pow_m_flow.port_a);
connect(pow_m_flow.port_b, den2.port_a);
connect(den2.port_b, roo2.ports[1]);
connect(den1.port_b, pow_V_flow.port_a);
connect(pow_V_flow.port_b, den2.port_a);
connect(den1.port_b, pow_1dat.port_a);
connect(den1.port_b, pow_2dat.port_a);
connect(pow_1dat.port_b, den2.port_a);
connect(pow_2dat.port_b, den2.port_a);
end PowerLaw;
Buildings.Airflow.Multizone.Examples.PressurizationData
Model showing how the 'Powerlaw_1DataPoint' model can be used when data is available from a pressurization test.
Information
This model illustrates the use of
Buildings.Airflow.Multizone.Point_m_flow
to model
infiltration through the building evelope for a known n50 value (also known as ACH50).
As the n50 value and the building volume is known,
the flow at 50 Pa is known. Dividing this flow accross the entire envelope
(typically surface weighted) and using
Buildings.Airflow.Multizone.Point_m_flow,
the infiltration airflow at lower pressure differences can be modelled.
In this example, the two models each represent 50% of the surface where airflow occured due to the pressurization test.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | n50 | 3 | ACH50, air changes at 50 Pa |
Modelica definition
model PressurizationData
"Model showing how the 'Powerlaw_1DataPoint' model can be used when data is available from a pressurization test."
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
parameter Real n50=3 "ACH50, air changes at 50 Pa";
BoundaryConditions.WeatherData.ReaderTMY3 weaDat(
filNam=Modelica.Utilities.Files.loadResource("modelica://Buildings/Resources/weatherdata/USA_CA_San.Francisco.Intl.AP.724940_TMY3.mos"));
Fluid.Sources.Outside_CpLowRise west(
redeclare package Medium = Medium,
s=5,
azi=Buildings.Types.Azimuth.W,
Cp0=0.6,
nPorts=1) "Model with outside conditions";
Fluid.Sources.Outside_CpLowRise east(
redeclare package Medium = Medium,
s=5,
azi=Buildings.Types.Azimuth.E,
Cp0=0.6,
nPorts=1) "Model with outside conditions";
Fluid.MixingVolumes.MixingVolume room(
redeclare package Medium = Medium,
V=2.5*5*5,
nPorts=2,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
m_flow_nominal=0.01) "Room model";
Buildings.Airflow.Multizone.Point_m_flow pow_1dat(
dpMea_nominal(displayUnit="Pa") = 50,
redeclare package Medium = Medium,
m=0.66,
mMea_flow_nominal=0.5*(room.V*n50*1.2))
"Crack in envelope representing 50% of the leakage area";
Buildings.Airflow.Multizone.Point_m_flow pow_1dat1(
dpMea_nominal(displayUnit="Pa") = 50,
redeclare package Medium = Medium,
m=0.66,
mMea_flow_nominal=0.5*(room.V*n50*1.2))
"Crack in envelope representing 50% of the leakage area";
equation
connect(weaDat.weaBus, west.weaBus);
connect(east.weaBus, weaDat.weaBus);
connect(east.ports[1], pow_1dat.port_a);
connect(pow_1dat.port_b,room. ports[1]);
connect(pow_1dat1.port_a,room. ports[2]);
connect(pow_1dat1.port_b, west.ports[1]);
end PressurizationData;
Buildings.Airflow.Multizone.Examples.ReverseBuoyancy
Model with four rooms and buoyancy-driven air circulation that reverses direction
Information
This model is similar than Buildings.Airflow.Multizone.Validation.ThreeRoomsContam but it has four instead of three rooms. The outdoor conditions are held constant at 10°C and atmospheric pressure. All four rooms are at different temperatures, with the rooms on the bottom floor being initially at a higher temperature than the rooms on the top floor. As time progresses, the temperatures of the two rooms on the respective floors asymptotically approach each other. The bottom floor eventually cools below the temperature of the top floor, because the bottom floor directly exchanges air with the outside.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ReverseBuoyancy
"Model with four rooms and buoyancy-driven air circulation that reverses direction"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
Buildings.Fluid.MixingVolumes.MixingVolume volBotEas(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
V=2.5*5*5,
T_start=273.15 + 25,
nPorts=5,
m_flow_nominal=0.001) "Volume of bottom floor, east room";
Buildings.Airflow.Multizone.Orifice oriOutBot(
redeclare package Medium = Medium,
m=0.5,
A=0.01,
dp_turbulent=0.1) "Orifice at bottom";
Buildings.Airflow.Multizone.MediumColumn colOutTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.Orifice oriOutTop(
redeclare package Medium = Medium,
m=0.5,
A=0.01,
dp_turbulent=0.1) "Orifice at top";
Buildings.Airflow.Multizone.MediumColumn colEasInTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.MediumColumn colEasInBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.MediumColumn colOutBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
MediumColumn colWesBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.Orifice oriWesTop(
redeclare package Medium = Medium,
m=0.5,
A=0.01,
dp_turbulent=0.1) "Orifice between west rooms";
Buildings.Airflow.Multizone.MediumColumn colWesTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.DoorDiscretizedOperable dooOpeClo(
redeclare package Medium = Medium,
LClo=20*1E-4,
wOpe=1,
hOpe=2.2,
hA=3/2,
hB=3/2,
CDOpe=0.78,
CDClo=0.78,
nCom=10,
vZer=0.01,
dp_turbulent=0.1) "Discretized door";
Fluid.Delays.DelayFirstOrder volBotWes(
redeclare package Medium = Medium,
m_flow_nominal=1.2,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
tau=2.5*5*5,
T_start=273.15 + 22,
nPorts=3,
p_start=101325) "Volume of bottom floor, west room";
Modelica.Blocks.Sources.Constant ope(k=1) "Constant signal for door opening";
Buildings.Airflow.Multizone.MediumColumn col1EasBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.Orifice oriEasTop(
redeclare package Medium = Medium,
m=0.5,
A=0.01,
dp_turbulent=0.1) "Orifice between east rooms";
Buildings.Airflow.Multizone.MediumColumn colEasTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
Buildings.Fluid.MixingVolumes.MixingVolume volTopEas(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
V=2.5*5*10,
T_start=273.15 + 21,
nPorts=3,
m_flow_nominal=0.001) "Volume of top floor, east room";
Buildings.Fluid.MixingVolumes.MixingVolume volTopWes(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T_start=273.15 + 20,
V=2.5*5*10,
nPorts=3,
m_flow_nominal=0.001) "Volume of top floor, west room";
Buildings.Airflow.Multizone.DoorDiscretizedOperable dooOpeCloTop(
redeclare package Medium = Medium,
LClo=20*1E-4,
wOpe=1,
hOpe=2.2,
hA=3/2,
hB=3/2,
CDOpe=0.78,
CDClo=0.78,
nCom=10,
vZer=0.01,
dp_turbulent=0.1) "Discretized door";
Buildings.Fluid.Sources.Boundary_pT volOut(
redeclare package Medium = Medium,
p=100000,
T=283.15,
nPorts=2) "Ambient conditions";
equation
connect(ope.y, dooOpeClo.y);
connect(ope.y, dooOpeCloTop.y);
connect(oriEasTop.port_b, colEasTop.port_b);
connect(oriWesTop.port_b, colWesBot.port_a);
connect(oriWesTop.port_a, colWesTop.port_b);
connect(oriOutBot.port_b, colOutBot.port_b);
connect(colEasInBot.port_b, oriOutBot.port_a);
connect(colEasInTop.port_a, oriOutTop.port_a);
connect(oriOutTop.port_b, colOutTop.port_a);
connect(volBotWes.ports[1], dooOpeClo.port_b2);
connect(volBotWes.ports[2], dooOpeClo.port_a1);
connect(colWesBot.port_b, volBotWes.ports[3]);
connect(volTopWes.ports[1], colWesTop.port_a);
connect(volTopWes.ports[2], dooOpeCloTop.port_b2);
connect(volTopWes.ports[3], dooOpeCloTop.port_a1);
connect(volTopEas.ports[1], dooOpeCloTop.port_b1);
connect(dooOpeCloTop.port_a2, volTopEas.ports[2]);
connect(colEasTop.port_a, volTopEas.ports[3]);
connect(oriEasTop.port_a, col1EasBot.port_a);
connect(dooOpeClo.port_b1, volBotEas.ports[1]);
connect(dooOpeClo.port_a2, volBotEas.ports[2]);
connect(colEasInBot.port_a, volBotEas.ports[3]);
connect(colEasInTop.port_b, volBotEas.ports[4]);
connect(col1EasBot.port_b, volBotEas.ports[5]);
connect(colOutBot.port_a, volOut.ports[1]);
connect(colOutTop.port_b, volOut.ports[2]);
end ReverseBuoyancy;
Buildings.Airflow.Multizone.Examples.ReverseBuoyancy3Zones
Model with three rooms and buoyancy-driven air circulation that reverses direction
Information
This model is similar than Buildings.Airflow.Multizone.Validation.ThreeRoomsContam. However, the initial temperatures are such that at the start of the simulation, the flow direction between the three rooms reverses direction.
At the start of the simulation, the outdoor temperature is 15°C, and the temperatures of the volumes are 20°C at the top, 22°C at the bottom west and 25°C at the bottom east. Thus, initially there is a net flow circulation in the counter-clock direction. Because the volume on the east exchanges air with the outside, it cools down fast. Once it cooled down sufficiently, the flow direction between the three rooms reverses because the air in the bottom east is heaviest.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model ReverseBuoyancy3Zones
"Model with three rooms and buoyancy-driven air circulation that reverses direction"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
Buildings.Fluid.MixingVolumes.MixingVolume volEas(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
V=2.5*5*5,
T_start=273.15 + 25,
nPorts=5,
m_flow_nominal=0.001) "Control volume for east room";
Buildings.Airflow.Multizone.Orifice oriOutBot(
redeclare package Medium = Medium,
m=0.5,
A=0.01,
dp_turbulent=0.1) "Orifice at bottom of east room";
Buildings.Airflow.Multizone.MediumColumn colOutTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.Orifice oriOutTop(
redeclare package Medium = Medium,
m=0.5,
A=0.01,
dp_turbulent=0.1) "Orifice at top of east room";
Buildings.Airflow.Multizone.MediumColumn colEasInTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Fluid.MixingVolumes.MixingVolume volOut(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
V=1E12,
T_start=273.15 + 15,
nPorts=2,
m_flow_nominal=0.001) "Control volume for outside";
Buildings.Airflow.Multizone.MediumColumn colEasInBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.MediumColumn colOutBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.MediumColumn colWesBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.Orifice oriWesTop(
redeclare package Medium = Medium,
m=0.5,
A=0.01,
dp_turbulent=0.1) "Orifice between west room and top";
Buildings.Airflow.Multizone.MediumColumn colWesTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.DoorDiscretizedOperable dooOpeClo(
redeclare package Medium = Medium,
LClo=20*1E-4,
wOpe=1,
hOpe=2.2,
hA=3/2,
hB=3/2,
CDOpe=0.78,
CDClo=0.78,
nCom=10,
vZer=0.01,
dp_turbulent=0.1) "Discretized door";
Modelica.Blocks.Sources.Constant ope(k=1) "Constant signal for door opening";
Buildings.Airflow.Multizone.MediumColumn col1EasBot(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromBottom)
"Medium column to compute static pressure of air";
Buildings.Airflow.Multizone.Orifice oriEasTop(
redeclare package Medium = Medium,
m=0.5,
A=0.01,
dp_turbulent=0.1) "Orifice between east room and top";
Buildings.Airflow.Multizone.MediumColumn colEasTop(
redeclare package Medium = Medium,
h=1.5,
densitySelection=Buildings.Airflow.Multizone.Types.densitySelection.fromTop)
"Medium column to compute static pressure of air";
Buildings.Fluid.MixingVolumes.MixingVolume volTop(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
T_start=273.15 + 20,
m_flow_nominal=0.001,
V=2.5*10*10,
nPorts=2) "Control volume for top floor room";
Buildings.Fluid.MixingVolumes.MixingVolume volWes(
redeclare package Medium = Medium,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
V=2.5*5*5,
T_start=273.15 + 22,
nPorts=3,
m_flow_nominal=0.001) "Control volume for west room";
equation
connect(dooOpeClo.port_b2, volWes.ports[1]);
connect(dooOpeClo.port_a1, volWes.ports[2]);
connect(dooOpeClo.port_b1, volEas.ports[1]);
connect(dooOpeClo.port_a2, volEas.ports[2]);
connect(colWesTop.port_b, oriWesTop.port_a);
connect(oriWesTop.port_b, colWesBot.port_a);
connect(colWesBot.port_b, volWes.ports[3]);
connect(colEasTop.port_b, oriEasTop.port_b);
connect(oriEasTop.port_a, col1EasBot.port_a);
connect(colEasInBot.port_a, volEas.ports[3]);
connect(colEasInTop.port_b, volEas.ports[4]);
connect(col1EasBot.port_b, volEas.ports[5]);
connect(colOutTop.port_b, volOut.ports[1]);
connect(volOut.ports[2], colOutBot.port_a);
connect(colOutBot.port_b, oriOutBot.port_b);
connect(oriOutBot.port_a, colEasInBot.port_b);
connect(colEasInTop.port_a, oriOutTop.port_a);
connect(oriOutTop.port_b, colOutTop.port_a);
connect(ope.y, dooOpeClo.y);
connect(colWesTop.port_a, volTop.ports[1]);
connect(colEasTop.port_a, volTop.ports[2]);
end ReverseBuoyancy3Zones;
Buildings.Airflow.Multizone.Examples.TrickleVent
Model with a trickle vent modelled using the models with flow based on tabulated data
Information
This model illustrates the use of the models Buildings.Airflow.Multizone.Table_V_flow and Buildings.Airflow.Multizone.Table_m_flow to model self regulating inlet vents. The models are connected to a common volume that emulates a room on one side and to outside conditions on the other side (east and west orientation respectively).
Extends from Modelica.Icons.Example (Icon for runnable examples).
Modelica definition
model TrickleVent
"Model with a trickle vent modelled using the models with flow based on tabulated data"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
BoundaryConditions.WeatherData.ReaderTMY3 weaDat(
filNam=Modelica.Utilities.Files.loadResource(
"modelica://Buildings/Resources/weatherdata/USA_CA_San.Francisco.Intl.AP.724940_TMY3.mos"))
"Weather data reader";
Fluid.Sources.Outside_CpLowRise west(
redeclare package Medium = Medium,
s=5,
azi=Buildings.Types.Azimuth.W,
Cp0=0.6,
nPorts=1) "Model with outside conditions";
Fluid.Sources.Outside_CpLowRise east(
redeclare package Medium = Medium,
s=5,
azi=Buildings.Types.Azimuth.E,
Cp0=0.6,
nPorts=1) "Model with outside conditions";
Fluid.MixingVolumes.MixingVolume room(
redeclare package Medium = Medium,
V=2.5*5*5,
nPorts=2,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
m_flow_nominal=0.01) "Room model";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow preHea
"Prescribed heat flow";
Modelica.Blocks.Continuous.LimPID con(
Td=10,
yMax=1,
yMin=-1,
Ti=60,
controllerType=Modelica.Blocks.Types.SimpleController.P,
k=5) "Controller to maintain volume temperature";
Modelica.Blocks.Sources.Constant TSet(k=293.15) "Temperature set point";
Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor temSen
"Temperature sensor";
Modelica.Blocks.Math.Gain gain(k=3000) "Gain block";
Buildings.Airflow.Multizone.Table_m_flow tabDat_m_flow(
redeclare package Medium = Medium,
dpMea_nominal = {-50, -25, -10, -5, -3, -2, -1, 0, 1, 2, 3, 4.5, 50},
mMea_flow_nominal = {-0.08709, -0.06158, -0.03895, -0.02754, -0.02133, -0.01742, -0.01232, 0, 0.01232, 0.01742, 0.02133, 0.02613, 0.02614})
"Self regulating trickle vent";
Buildings.Airflow.Multizone.Table_V_flow tabDat_V_flow(
redeclare package Medium = Medium,
dpMea_nominal = {-50, -25, -10, -5, -3, -2, -1, 0, 1, 2, 3, 4.5, 50},
VMea_flow_nominal = {-0.104508, -0.073896, -0.04674, -0.033048, -0.025596, -0.020904, -0.014784, 0, 0.014784, 0.020904, 0.025596, 0.031356, 0.031368})
"Self regulating trickle vent";
equation
connect(weaDat.weaBus, west.weaBus);
connect(east.weaBus, weaDat.weaBus);
connect(TSet.y,con. u_s);
connect(temSen.T,con. u_m);
connect(gain.u,con. y);
connect(gain.y,preHea. Q_flow);
connect(room.heatPort, temSen.port);
connect(preHea.port,room. heatPort);
connect(east.ports[1], tabDat_m_flow.port_a);
connect(tabDat_m_flow.port_b,room. ports[1]);
connect(tabDat_V_flow.port_a,room. ports[2]);
connect(tabDat_V_flow.port_b, west.ports[1]);
end TrickleVent;
Buildings.Airflow.Multizone.Examples.ZonalFlow
Model with prescribed air exchange between two volumes
Information
This example illustrates the use of the models that
exchange a prescribed flow rate between the
volumes that are attached to it.
The block ACS prescribes the air exchange rate to
5 air changes per hour.
The instance zonFlo takes as an input the air change per seconds,
and the instance floExc takes as inputs the mass flow rate.
For both instances, the air flows from
rooA to rooB, and
from rooB to rooA.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Volume | volA | 100 | Volume of room A [m3] |
| Volume | volB | 1 | Volume of room B [m3] |
Modelica definition
model ZonalFlow "Model with prescribed air exchange between two volumes"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Air;
parameter Modelica.Units.SI.Volume volA=100 "Volume of room A";
parameter Modelica.Units.SI.Volume volB=1 "Volume of room B";
Buildings.Fluid.MixingVolumes.MixingVolume rooA(
V=volA,
redeclare package Medium = Medium,
X_start={0.015,0.985},
T_start=303.15,
nPorts=4,
m_flow_nominal=0.001,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) "Room A";
Buildings.Fluid.MixingVolumes.MixingVolume rooB(
V=volB,
redeclare package Medium = Medium,
X_start={0.01,0.99},
T_start=293.15,
nPorts=4,
m_flow_nominal=0.001,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) "Room B";
Modelica.Blocks.Sources.Constant ACS(k=5/3600) "Air change rate per second";
ZonalFlow_ACS zonFlo(
redeclare package Medium = Medium,
V=min(volA, volB))
"Model for prescribed flow exchange between two volume with air change per second as input";
Modelica.Blocks.Sources.Constant m_flow(k=0.02) "Exchange mass flow rate";
ZonalFlow_m_flow floExc(redeclare package Medium = Medium)
"Model for prescribed flow exchange between two volumes with mass flow rate as inputs";
equation
connect(rooA.ports[1], zonFlo.port_a1);
connect(zonFlo.port_b1, rooB.ports[1]);
connect(zonFlo.port_b2, rooA.ports[2]);
connect(zonFlo.port_a2, rooB.ports[2]);
connect(zonFlo.ACS, ACS.y);
connect(floExc.mAB_flow, m_flow.y);
connect(m_flow.y, floExc.mBA_flow);
connect(floExc.port_a1, rooA.ports[3]);
connect(floExc.port_b1, rooB.ports[3]);
connect(floExc.port_a2, rooB.ports[4]);
connect(floExc.port_b2, rooA.ports[4]);
end ZonalFlow;