Buildings.Fluid.Sources.BaseClasses
Package with base classes for Buildings.Fluid.Sources
Information
This package contains base classes that are used to construct the models in Buildings.Fluid.Sources.
Extends from Modelica.Icons.BasesPackage (Icon for packages containing base classes).
Package Content
| Name | Description |
|---|---|
 Outside
|
Boundary that takes weather data, and optionally trace substances, as an input |
 PartialPropertySource
|
Partial model for overriding fluid properties that flow through the component |
 PartialSource
|
Partial component source with one fluid connector |
 PartialSource_Xi_C
|
Partial component source with parameter definitions for Xi and C |
Buildings.Fluid.Sources.BaseClasses.Outside
Boundary that takes weather data, and optionally trace substances, as an input
Information
This is the base class for models that describes boundary conditions for pressure, enthalpy, and species concentration that can be obtained from weather data, and that may be modified based on the wind pressure.
If the parameter use_C_in is false (default option),
the C parameter
is used as the trace substance for flow that leaves the component, and the
C_in input connector is disabled; if use_C_in is true,
then the C parameter is ignored, and the value provided by the input connector is used instead.
Note that boundary temperature, mass fractions and trace substances have only an effect if the mass flow is from the boundary into the port. If mass is flowing from the port into the boundary, the boundary definitions, with exception of boundary pressure, do not have an effect.
Extends from Buildings.Fluid.Sources.BaseClasses.PartialSource (Partial component source with one fluid connector).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Boolean | use_C_in | false | Get the trace substances from the input connector |
| ExtraProperty | C[Medium.nC] | fill(0, Medium.nC) | Fixed values of trace substances |
| Advanced | |||
| Boolean | verifyInputs | true | Set to true to stop the simulation with an error if the medium temperature is outside its allowable range |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPorts_b | ports[nPorts] | Fluid ports |
| input RealInput | C_in[Medium.nC] | Prescribed boundary trace substances |
| Bus | weaBus | Bus with weather data |
Modelica definition
partial model Outside
"Boundary that takes weather data, and optionally trace substances, as an input"
extends Buildings.Fluid.Sources.BaseClasses.PartialSource(final verifyInputs=true);
parameter Boolean use_C_in = false
"Get the trace substances from the input connector";
parameter Medium.ExtraProperty C[Medium.nC](
final quantity=Medium.extraPropertiesNames)=fill(0, Medium.nC)
"Fixed values of trace substances";
Modelica.Blocks.Interfaces.RealInput C_in[Medium.nC](
final quantity=Medium.extraPropertiesNames) if use_C_in
"Prescribed boundary trace substances";
Buildings.BoundaryConditions.WeatherData.Bus weaBus "Bus with weather data";
protected
final parameter Boolean singleSubstance = (Medium.nX == 1)
"True if single substance medium";
Buildings.Utilities.Psychrometrics.X_pTphi x_pTphi
if not singleSubstance "Block to compute water vapor concentration";
Modelica.Blocks.Interfaces.RealInput T_in_internal(final unit="K",
displayUnit="degC")
"Needed to connect to conditional connector";
Modelica.Blocks.Interfaces.RealInput h_internal = Medium.specificEnthalpy(
Medium.setState_pTX(p_in_internal, T_in_internal, X_in_internal));
equation
// Check medium properties
Modelica.Fluid.Utilities.checkBoundary(Medium.mediumName, Medium.substanceNames,
Medium.singleState, true, X_in_internal, "Boundary_pT");
// Conditional connectors for trace substances
connect(C_in, C_in_internal);
if not use_C_in then
C_in_internal = C;
end if;
// Connections to input. This is required to obtain the data from
// the weather bus in case that the component x_pTphi is conditionally removed
connect(weaBus.TDryBul, T_in_internal);
// Connections to compute species concentration
connect(p_in_internal, x_pTphi.p_in);
connect(T_in_internal, x_pTphi.T);
connect(weaBus.relHum, x_pTphi.phi);
connect(X_in_internal, x_pTphi.X);
if singleSubstance then
X_in_internal = ones(Medium.nX);
end if;
connect(X_in_internal[1:Medium.nXi], Xi_in_internal);
ports.C_outflow = fill(C_in_internal, nPorts);
if not verifyInputs then
h_internal = Medium.h_default;
p_in_internal = Medium.p_default;
X_in_internal = Medium.X_default;
T_in_internal = Medium.T_default;
end if;
// Assign medium properties
connect(medium.h, h_internal);
connect(medium.Xi, Xi_in_internal);
for i in 1:nPorts loop
ports[i].p = p_in_internal;
ports[i].h_outflow = h_internal;
ports[i].Xi_outflow = Xi_in_internal;
end for;
end Outside;
Buildings.Fluid.Sources.BaseClasses.PartialPropertySource
Partial model for overriding fluid properties that flow through the component
Information
Model that changes the properties, but not the mass flow rate, of the fluid that passes through it.
Typical use and important parameters
If allowFlowReversal=true, then the properties are changed for both flow directions,
i.e., from port_a to port_b and
from port_b to port_a.
Dynamics
This model has no dynamics.
Extends from Buildings.Fluid.Interfaces.PartialTwoPort (Partial component with two ports).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Inputs | |||
| Boolean | use_Xi_in | false | Set to true to get the composition from the input connector |
| Boolean | use_C_in | false | Set to true to get the trace substances from the input connector |
| Assumptions | |||
| Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
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 | Xi_in[Medium.nXi] | Prescribed values for composition |
| input RealInput | C_in[Medium.nC] | Prescribed values for trace substances |
Modelica definition
partial model PartialPropertySource
"Partial model for overriding fluid properties that flow through the component"
extends Buildings.Fluid.Interfaces.PartialTwoPort;
parameter Boolean use_Xi_in= false
"Set to true to get the composition from the input connector";
parameter Boolean use_C_in= false
"Set to true to get the trace substances from the input connector";
Modelica.Blocks.Interfaces.RealInput Xi_in[Medium.nXi] if use_Xi_in
"Prescribed values for composition";
Modelica.Blocks.Interfaces.RealInput C_in[Medium.nC](
final quantity=Medium.extraPropertiesNames) if use_C_in
"Prescribed values for trace substances";
protected
Modelica.Blocks.Interfaces.RealOutput h_internal_a
"Internal outlet value of port_a.h_outflow";
Modelica.Blocks.Interfaces.RealOutput h_internal_b
"Internal outlet value of port_b.h_outflow";
Modelica.Blocks.Interfaces.RealOutput h_in_a = inStream(port_a.h_outflow)
"Connector for inStream value of port_a.h_outflow";
Modelica.Blocks.Interfaces.RealOutput h_in_b = inStream(port_b.h_outflow)
"Connector for inStream value of port_b.h_outflow";
Modelica.Blocks.Interfaces.RealOutput[Medium.nXi] Xi_internal_a
"Internal outlet value of port_a.Xi_outflow";
Modelica.Blocks.Interfaces.RealOutput[Medium.nXi] Xi_internal_b
"Internal outlet value of port_b.Xi_outflow";
Modelica.Blocks.Interfaces.RealOutput[Medium.nXi] Xi_in_a = inStream(port_a.Xi_outflow)
"Connector for inStream value of port_a.Xi_outflow";
Modelica.Blocks.Interfaces.RealOutput[Medium.nXi] Xi_in_b = inStream(port_b.Xi_outflow)
"Connector for inStream value of port_b.Xi_outflow";
Modelica.Blocks.Interfaces.RealInput[Medium.nC] C_internal_a
"Internal outlet value of port_a.C_outflow";
Modelica.Blocks.Interfaces.RealInput[Medium.nC] C_internal_b
"Internal outlet value of port_b.C_outflow";
Modelica.Blocks.Interfaces.RealOutput[Medium.nC] C_in_a = inStream(port_a.C_outflow)
"Connector for inStream value of port_a.C_outflow";
Modelica.Blocks.Interfaces.RealOutput[Medium.nC] C_in_b = inStream(port_b.C_outflow)
"Connector for inStream value of port_b.C_outflow";
equation
connect(Xi_internal_a, Xi_in);
connect(Xi_internal_b, Xi_in);
if not (use_Xi_in) then
connect(Xi_internal_a,Xi_in_b);
connect(Xi_internal_b,Xi_in_a);
end if;
connect(C_internal_a, C_in);
connect(C_internal_b, C_in);
if not (use_C_in) then
connect(C_internal_a,C_in_b);
connect(C_internal_b,C_in_a);
end if;
port_a.h_outflow = if allowFlowReversal then h_internal_a else Medium.h_default;
port_b.h_outflow = h_internal_b;
port_a.Xi_outflow = if allowFlowReversal then Xi_internal_a else Medium.X_default[1:Medium.nXi];
port_b.Xi_outflow = Xi_internal_b;
port_a.C_outflow = if allowFlowReversal then C_internal_a else zeros(Medium.nC);
port_b.C_outflow = C_internal_b;
port_a.p = port_b.p;
port_a.m_flow + port_b.m_flow = 0;
end PartialPropertySource;
Buildings.Fluid.Sources.BaseClasses.PartialSource
Partial component source with one fluid connector
Information
Partial model for a fluid source that either prescribes
pressure or mass flow rate.
Models that extend this partial model need to prescribe the outflowing
specific enthalpy, composition and trace substances.
This partial model only declares the ports
and ensures that the pressures at all ports are equal.
Implementation
If the parameter verifyInputs is set to true,
then a protected instance of medium base properties is enabled.
This instance verifies that the
medium temperature is within the bounds T_min and T_max,
where T_min and T_max are constants of the Medium.
If the temperature is outside these bounds, the simulation will stop with an error.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | Modelica.Media.Interfaces.Pa... | Medium in the component | |
| Advanced | |||
| Boolean | verifyInputs | false | Set to true to stop the simulation with an error if the medium temperature is outside its allowable range |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package Medium | Medium in the component | |
| FluidPorts_b | ports[nPorts] | Fluid ports |
Modelica definition
partial model PartialSource
"Partial component source with one fluid connector"
replaceable package Medium =
Modelica.Media.Interfaces.PartialMedium "Medium in the component";
parameter Integer nPorts=0 "Number of ports";
parameter Boolean verifyInputs = false
"Set to true to stop the simulation with an error if the medium temperature is outside its allowable range";
Modelica.Fluid.Interfaces.FluidPorts_b ports[nPorts](
redeclare each package Medium = Medium,
each m_flow(max=if flowDirection == Modelica.Fluid.Types.PortFlowDirection.Leaving
then 0 else +Modelica.Constants.inf,
min=if flowDirection == Modelica.Fluid.Types.PortFlowDirection.Entering
then 0 else -Modelica.Constants.inf))
"Fluid ports";
protected
parameter Modelica.Fluid.Types.PortFlowDirection flowDirection=Modelica.Fluid.Types.PortFlowDirection.Bidirectional
"Allowed flow direction";
Modelica.Blocks.Interfaces.RealInput p_in_internal(final unit="Pa")
"Needed to connect to conditional connector";
Medium.BaseProperties medium if verifyInputs "Medium in the source";
Modelica.Blocks.Interfaces.RealInput Xi_in_internal[Medium.nXi](
each final unit = "kg/kg")
"Needed to connect to conditional connector";
Modelica.Blocks.Interfaces.RealInput X_in_internal[Medium.nX](
each final unit = "kg/kg")
"Needed to connect to conditional connector";
Modelica.Blocks.Interfaces.RealInput C_in_internal[Medium.nC](
final quantity=Medium.extraPropertiesNames)
"Needed to connect to conditional connector";
initial equation
// Only one connection allowed to a port to avoid unwanted ideal mixing
for i in 1:nPorts loop
assert(cardinality(ports[i]) <= 1,"
Each ports[i] of boundary shall at most be connected to one component.
If two or more connections are present, ideal mixing takes
place in these connections, which is usually not the intention
of the modeller. Increase nPorts to add an additional port.
");
end for;
equation
connect(medium.p, p_in_internal);
end PartialSource;
Buildings.Fluid.Sources.BaseClasses.PartialSource_Xi_C
Partial component source with parameter definitions for Xi and C
Information
Partial model that defines outflowing properties
ports.Xi_outflow and ports.C_outflow
using an optional input for both.
Otherwise the parameter value is used.
Extends from Buildings.Fluid.Sources.BaseClasses.PartialSource (Partial component source with one fluid connector).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Conditional inputs | |||
| Boolean | use_Xi_in | false | Get the composition (independent fractions) from the input connector |
| Boolean | use_C_in | false | Get the trace substances from the input connector |
| Fixed inputs | |||
| MassFraction | X[Medium.nX] | Medium.X_default | Fixed value of composition [kg/kg] |
| ExtraProperty | C[Medium.nC] | fill(0, Medium.nC) | Fixed values of trace substances |
| Advanced | |||
| Boolean | verifyInputs | false | Set to true to stop the simulation with an error if the medium temperature is outside its allowable range |
| Boolean | use_X_in | false | Get the composition (all fractions) from the input connector |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPorts_b | ports[nPorts] | Fluid ports |
| input RealInput | X_in[Medium.nX] | Prescribed boundary composition [kg/kg] |
| input RealInput | Xi_in[Medium.nXi] | Prescribed boundary composition [kg/kg] |
| input RealInput | C_in[Medium.nC] | Prescribed boundary trace substances |
Modelica definition
partial model PartialSource_Xi_C
"Partial component source with parameter definitions for Xi and C"
extends Buildings.Fluid.Sources.BaseClasses.PartialSource;
parameter Boolean use_X_in = false
"Get the composition (all fractions) from the input connector";
parameter Boolean use_Xi_in = false
"Get the composition (independent fractions) from the input connector";
parameter Boolean use_C_in = false
"Get the trace substances from the input connector";
parameter Medium.MassFraction X[Medium.nX](
final quantity=Medium.substanceNames) = Medium.X_default
"Fixed value of composition";
parameter Medium.ExtraProperty C[Medium.nC](
final quantity=Medium.extraPropertiesNames) = fill(0, Medium.nC)
"Fixed values of trace substances";
Modelica.Blocks.Interfaces.RealInput X_in[Medium.nX](
each final unit = "kg/kg",
final quantity=Medium.substanceNames) if use_X_in
"Prescribed boundary composition";
Modelica.Blocks.Interfaces.RealInput Xi_in[Medium.nXi](
each final unit = "kg/kg",
final quantity=Medium.substanceNames[1:Medium.nXi]) if use_Xi_in
"Prescribed boundary composition";
Modelica.Blocks.Interfaces.RealInput C_in[Medium.nC](
final quantity=Medium.extraPropertiesNames) if use_C_in
"Prescribed boundary trace substances";
initial equation
assert(not use_X_in or not use_Xi_in,
"Cannot use both X and Xi inputs, choose either use_X_in or use_Xi_in.");
if not use_X_in and not use_Xi_in then
Modelica.Fluid.Utilities.checkBoundary(Medium.mediumName, Medium.substanceNames,
Medium.singleState, true, X_in_internal, "Boundary_pT");
end if;
equation
if use_X_in or use_Xi_in then
Modelica.Fluid.Utilities.checkBoundary(Medium.mediumName, Medium.substanceNames,
Medium.singleState, true, X_in_internal, "Boundary_pT");
end if;
// Assign Xi_in_internal and X_in_internal
// Note that at most one of X_in or Xi_in is present
connect(X_in, X_in_internal);
connect(Xi_in, Xi_in_internal);
if use_Xi_in then
// Must assign all components of X_in_internal, using Xi_in
X_in_internal[1:Medium.nXi] = Xi_in_internal[1:Medium.nXi];
// If reducedX = true, medium contains the equation sum(X) = 1.0
// Media with only one substance (e.g., water) have reducedX=true
// FlueGas and SimpleNaturalGas has reducedX = false
if Medium.reducedX then
X_in_internal[Medium.nX] = 1-sum(Xi_in_internal);
end if;
elseif use_X_in then
X_in_internal[1:Medium.nXi] = Xi_in_internal[1:Medium.nXi];
else
// No connector is used. Use parameter X.
X_in_internal = X;
Xi_in_internal = X[1:Medium.nXi];
end if;
connect(C_in, C_in_internal);
if not use_C_in then
C_in_internal = C;
end if;
for i in 1:nPorts loop
ports[i].Xi_outflow = Xi_in_internal;
ports[i].C_outflow = C_in_internal;
end for;
end PartialSource_Xi_C;