Buildings.Fluid.HydronicConfigurations.Components
Package with component models
Information
This package contains component models that are used to construct the models within Buildings.Fluid.HydronicConfigurations. Those components are "wrapper" or "container" classes that conditionally instantiate models from Buildings.Fluid and enable switching from one model to another by a simple parameter assignment.
Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
| Name | Description |
|---|---|
 Pump
|
Container class for circulating pumps |
 ThreeWayValve
|
Container class for three-way valves |
 TwoWayValve
|
Container class for two-way valves |
Buildings.Fluid.HydronicConfigurations.Components.Pump
Container class for circulating pumps
Information
This is a container class for pump models from Buildings.Fluid.Movers.
Two parameters allow configuring the model.
-
The parameter
typenables selecting the type of pump based on the enumeration Buildings.Fluid.HydronicConfigurations.Types.Pump. If "No pump" is selected the model resolves into a simple fluid direct pass-through. -
The parameter
typModenables selecting the type of pump model based on the enumeration Buildings.Fluid.HydronicConfigurations.Types.PumpModel.
The model takes the following input variables that are conditional
to the parameter typ.
| Variable | Type (unit) | Condition | Description |
|---|---|---|---|
y1 |
Boolean | Only available if typ<>None |
Start signal |
y |
Real (-) | Only available if typ==VariableInput |
Analog control signal. Whatever the type of pump model (specified with typMod) the container class takes a non-dimensional input between 0 and 1. |
Extends from Buildings.Fluid.Interfaces.LumpedVolumeDeclarations (Declarations for lumped volumes), Buildings.Fluid.Interfaces.PartialTwoPortInterface (Partial model transporting fluid between two ports without storing mass or energy).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Generic | per | redeclare parameter Building... | Record with performance data |
| Boolean | addPowerToMedium | true | Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations) |
| Configuration | |||
| Pump | typ | Buildings.Fluid.HydronicConf... | Type of secondary pump |
| PumpModel | typMod | Buildings.Fluid.HydronicConf... | Type of pump model |
| Nominal condition | |||
| PressureDifference | dp_nominal | Pump head at design conditions [Pa] | |
| Control | |||
| InputType | inputType | Buildings.Fluid.Types.InputT... | Control input type |
| Dynamics | |||
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Real | mSenFac | 1 | Factor for scaling the sensible thermal mass of the volume |
| Filtered speed | |||
| Boolean | use_inputFilter | true | = true, if speed is filtered with a 2nd order CriticalDamping filter |
| Time | riseTime | 30 | Rise time of the filter (time to reach 99.6 % of the speed) [s] |
| Init | init | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Advanced | |||
| Dynamics | |||
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state, must be steady state if energyDynamics is steady state |
| MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| 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 |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| 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 | y | Analog control signal [1] |
| input BooleanInput | y1 | Start signal |
| output RealOutput | y_actual | Actual pump input value that is used for computations [1] |
| output RealOutput | P | Electrical power consumed [W] |
| HeatPort_a | heatPort | Heat dissipation to environment |
Modelica definition
model Pump "Container class for circulating pumps"
extends Buildings.Fluid.Interfaces.LumpedVolumeDeclarations(
final massDynamics=energyDynamics,
final mSenFac=1);
extends Buildings.Fluid.Interfaces.PartialTwoPortInterface(
m_flow_nominal(
final min=Modelica.Constants.small),
show_T=false,
port_a(
h_outflow(start=h_outflow_start)),
port_b(
h_outflow(start=h_outflow_start),
p(start=p_start),
final m_flow(max = if allowFlowReversal then +Modelica.Constants.inf else 0)));
parameter Buildings.Fluid.HydronicConfigurations.Types.Pump typ=
Buildings.Fluid.HydronicConfigurations.Types.Pump.VariableInput
"Type of secondary pump";
parameter Buildings.Fluid.HydronicConfigurations.Types.PumpModel typMod=
Buildings.Fluid.HydronicConfigurations.Types.PumpModel.Speed
"Type of pump model";
parameter Modelica.Units.SI.PressureDifference dp_nominal(displayUnit="Pa")
"Pump head at design conditions";
replaceable parameter Buildings.Fluid.Movers.Data.Generic per
constrainedby Buildings.Fluid.Movers.Data.Generic(
pressure(
V_flow={0, 1, 2} * m_flow_nominal / rho_default,
dp={1.14, 1, 0.42} * dp_nominal))
"Record with performance data";
parameter Buildings.Fluid.Types.InputType inputType=
Buildings.Fluid.Types.InputType.Continuous
"Control input type";
parameter Boolean addPowerToMedium=true
"Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations)";
// Classes used to implement the filtered speed
parameter Boolean use_inputFilter=true
"= true, if speed is filtered with a 2nd order CriticalDamping filter";
parameter Modelica.Units.SI.Time riseTime=30
"Rise time of the filter (time to reach 99.6 % of the speed)";
parameter Modelica.Blocks.Types.Init init=Modelica.Blocks.Types.Init.InitialOutput
"Type of initialization (no init/steady state/initial state/initial output)";
// Variables
Modelica.Units.SI.VolumeFlowRate VMachine_flow = V_flow.V_flow
"Volume flow rate";
Modelica.Units.SI.PressureDifference dpMachine(displayUnit="Pa") = port_b.p - port_a.p
"Pressure rise";
Buildings.Controls.OBC.CDL.Interfaces.RealInput y(
final unit="1")
if typ==Buildings.Fluid.HydronicConfigurations.Types.Pump.VariableInput
"Analog control signal";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput y1
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Start signal";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput y_actual(
final unit="1") if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Actual pump input value that is used for computations";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput P(
quantity="Power",
final unit="W") if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Electrical power consumed";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a heatPort
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Heat dissipation to environment";
Movers.FlowControlled_dp pumDp(
redeclare final package Medium = Medium,
final energyDynamics=energyDynamics,
final p_start=p_start,
final T_start=T_start,
final X_start=X_start,
final C_start=C_start,
final C_nominal=C_nominal,
final m_flow_nominal=m_flow_nominal,
final m_flow_small=m_flow_small,
final show_T=show_T,
final inputType=Buildings.Fluid.Types.InputType.Continuous,
final addPowerToMedium=addPowerToMedium,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final per=per)
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
and typMod==Buildings.Fluid.HydronicConfigurations.Types.PumpModel.Head
"Pump with ideally controlled head as input signal";
Movers.SpeedControlled_y pumSpe(
redeclare final package Medium = Medium,
final energyDynamics=energyDynamics,
final p_start=p_start,
final T_start=T_start,
final X_start=X_start,
final C_start=C_start,
final C_nominal=C_nominal,
final m_flow_small=m_flow_small,
final show_T=show_T,
final inputType=Buildings.Fluid.Types.InputType.Continuous,
final addPowerToMedium=addPowerToMedium,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final per=per)
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
and typMod==Buildings.Fluid.HydronicConfigurations.Types.PumpModel.Speed
"Pump with ideally controlled normalized speed as input";
Movers.FlowControlled_m_flow pumFlo(
redeclare final package Medium = Medium,
final m_flow_nominal=m_flow_nominal,
final energyDynamics=energyDynamics,
final p_start=p_start,
final T_start=T_start,
final X_start=X_start,
final C_start=C_start,
final C_nominal=C_nominal,
final m_flow_small=m_flow_small,
final show_T=show_T,
final inputType=Buildings.Fluid.Types.InputType.Continuous,
final addPowerToMedium=addPowerToMedium,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final per=per)
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
and typMod==Buildings.Fluid.HydronicConfigurations.Types.PumpModel.MassFlowRate
"Pump with ideally controlled mass flow rate as input";
Sensors.VolumeFlowRate V_flow(
redeclare final package Medium = Medium,
final m_flow_nominal=m_flow_nominal)
"Volume flow rate";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter scaHea(
final k=dp_nominal)
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Scale control input to design head";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter scaSpe(
final k=per.speed_nominal)
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Scale control input to design speed";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter scaFlo(
final k=m_flow_nominal)
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Scale control input to design flow rate";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant zer(final k=0.0)
"Zero";
Buildings.Controls.OBC.CDL.Reals.Switch swi
if typ<>Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Switch on/off";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant One(final k=1.0)
if typ==Buildings.Fluid.HydronicConfigurations.Types.Pump.NoVariableInput
"one";
FixedResistances.LosslessPipe noPum(
redeclare final package Medium = Medium,
final m_flow_nominal=m_flow_nominal)
if typ==Buildings.Fluid.HydronicConfigurations.Types.Pump.None
"Direct fluid pass-through in case of no pump";
protected
final parameter Modelica.Units.SI.Density rho_default=Medium.density_pTX(
p=Medium.p_default,
T=Medium.T_default,
X=Medium.X_default) "Default medium density";
final parameter Medium.ThermodynamicState sta_start=Medium.setState_pTX(
T=T_start,
p=p_start,
X=X_start) "Medium state at start values";
final parameter Modelica.Units.SI.SpecificEnthalpy h_outflow_start=
Medium.specificEnthalpy(sta_start) "Start value for outflowing enthalpy";
equation
connect(pumDp.port_b, port_b);
connect(pumSpe.port_b, port_b);
connect(pumDp.heatPort, heatPort);
connect(pumSpe.heatPort, heatPort);
connect(pumFlo.heatPort, heatPort);
connect(pumFlo.port_b, port_b);
connect(pumDp.P, P);
connect(pumDp.y_actual, y_actual);
connect(pumSpe.P, P);
connect(pumSpe.y_actual, y_actual);
connect(pumFlo.P, P);
connect(pumFlo.y_actual, y_actual);
connect(port_a, V_flow.port_a);
connect(V_flow.port_b, pumSpe.port_a);
connect(V_flow.port_b, pumDp.port_a);
connect(V_flow.port_b, pumFlo.port_a);
connect(scaHea.y, pumDp.dp_in);
connect(scaSpe.y, pumSpe.y);
connect(scaFlo.y, pumFlo.m_flow_in);
connect(zer.y, swi.u3);
connect(y, swi.u1);
connect(y1, swi.u2);
connect(swi.y, scaHea.u);
connect(swi.y, scaSpe.u);
connect(swi.y, scaFlo.u);
connect(One.y, swi.u1);
connect(V_flow.port_b, noPum.port_a);
connect(noPum.port_b, port_b);
end Pump;
Buildings.Fluid.HydronicConfigurations.Components.ThreeWayValve
Container class for three-way valves
Information
This is a container class for three-way valve models from Buildings.Fluid.Actuators.Valves.
The parameter typCha allows configuring the model
by selecting the valve characteristic to be used based on the enumeration
Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.
The default setting for the ratio of
the Kvs coefficient between the bypass branch and the
direct branch is fraK=1.0, see
Buildings.Fluid.HydronicConfigurations.UsersGuide.ControlValves
for the justification.
Extends from Buildings.Fluid.Interfaces.LumpedVolumeDeclarations (Declarations for lumped volumes), Buildings.Fluid.Actuators.BaseClasses.ValveParameters (Model with parameters for valves).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Generic | flowCharacteristics1 | flowCharacteristics1(y={0,1}... | Table with flow characteristics for direct flow path at port_1 |
| Generic | flowCharacteristics3 | flowCharacteristics3(y={0,1}... | Table with flow characteristics for bypass flow path at port_3 |
| Real | R | 50 | Rangeability, R=50...100 typically |
| Real | delta0 | 0.01 | Range of significant deviation from equal percentage law |
| Real | fraK | 1.0 | Fraction Kv(port_3→port_2)/Kv(port_1→port_2) |
| Real | l[2] | {0.0001,0.0001} | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Flow Coefficient | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av | Av (metric) flow coefficient [m2] | |
| Pressure-flow linearization | |||
| Real | deltaM | 0.02 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] | |
| PressureDifference | dpFixed_nominal[2] | {0,0} | Nominal pressure drop of pipes and other equipment in flow legs at port_1 and port_3 [Pa] |
| Configuration | |||
| ValveCharacteristic | typCha | Buildings.Fluid.HydronicConf... | Valve characteristic |
| Dynamics | |||
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Real | mSenFac | 1 | Factor for scaling the sensible thermal mass of the volume |
| Nominal condition | |||
| Time | tau | 10 | Time constant at nominal flow for dynamic energy and momentum balance [s] |
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTime | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | init | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | y_start | 1 | Initial position of actuator |
| Advanced | |||
| Dynamics | |||
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state, must be steady state if energyDynamics is steady state |
| Nominal condition | |||
| Density | rhoStd | Medium.density_pTX(101325, 2... | Inlet density for which valve coefficients are defined [kg/m3] |
| Boolean | linearized[2] | {false,false} | = true, use linear relation between m_flow and dp for any flow rate |
| Boolean | from_dp | true | = true, use m_flow = f(dp) else dp = f(m_flow) |
| PortFlowDirection | portFlowDirection_1 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_1 |
| PortFlowDirection | portFlowDirection_2 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_2 |
| PortFlowDirection | portFlowDirection_3 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_3 |
| Boolean | verifyFlowReversal | false | =true, to assert that the flow does not reverse when portFlowDirection_* does not equal Bidirectional |
| 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 |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_1 | First port, typically inlet |
| FluidPort_b | port_2 | Second port, typically outlet |
| FluidPort_a | port_3 | Third port, can be either inlet or outlet |
| input RealInput | y | Input control signal [1] |
| output RealOutput | y_actual | Actual actuator position |
Modelica definition
model ThreeWayValve "Container class for three-way valves"
extends Buildings.Fluid.Interfaces.LumpedVolumeDeclarations(
final massDynamics=energyDynamics,
final mSenFac=1);
extends Buildings.Fluid.Actuators.BaseClasses.ValveParameters(
rhoStd=Medium.density_pTX(101325, 273.15+4, Medium.X_default));
parameter Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic
typCha=Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.EqualPercentage
"Valve characteristic";
parameter Buildings.Fluid.Actuators.Valves.Data.Generic flowCharacteristics1(
y={0,1},
phi={0.0001,1})
"Table with flow characteristics for direct flow path at port_1";
parameter Buildings.Fluid.Actuators.Valves.Data.Generic flowCharacteristics3(
y={0,1},
phi={0.0001,1})
"Table with flow characteristics for bypass flow path at port_3";
parameter Modelica.Units.SI.PressureDifference dpFixed_nominal[2](
each displayUnit="Pa")={0,0}
"Nominal pressure drop of pipes and other equipment in flow legs at port_1 and port_3";
parameter Real R = 50 "Rangeability, R=50...100 typically";
parameter Real delta0 = 0.01
"Range of significant deviation from equal percentage law";
parameter Real fraK(min=0, max=1) = 1.0
"Fraction Kv(port_3→port_2)/Kv(port_1→port_2)";
parameter Real[2] l(each min=0, each max=1) = {0.0001, 0.0001}
"Valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Real deltaM = 0.02
"Fraction of nominal flow rate where linearization starts, if y=1";
parameter Boolean[2] linearized = {false, false}
"= true, use linear relation between m_flow and dp for any flow rate";
parameter Modelica.Units.SI.Time tau=10
"Time constant at nominal flow for dynamic energy and momentum balance";
parameter Boolean from_dp = true
"= true, use m_flow = f(dp) else dp = f(m_flow)";
parameter Modelica.Fluid.Types.PortFlowDirection portFlowDirection_1=Modelica.Fluid.Types.PortFlowDirection.Bidirectional
"Flow direction for port_1";
parameter Modelica.Fluid.Types.PortFlowDirection portFlowDirection_2=Modelica.Fluid.Types.PortFlowDirection.Bidirectional
"Flow direction for port_2";
parameter Modelica.Fluid.Types.PortFlowDirection portFlowDirection_3=Modelica.Fluid.Types.PortFlowDirection.Bidirectional
"Flow direction for port_3";
parameter Boolean verifyFlowReversal = false
"=true, to assert that the flow does not reverse when portFlowDirection_* does not equal Bidirectional";
parameter Boolean use_inputFilter=true
"= true, if opening is filtered with a 2nd order CriticalDamping filter";
parameter Modelica.Units.SI.Time riseTime=120
"Rise time of the filter (time to reach 99.6 % of an opening step)";
parameter Modelica.Blocks.Types.Init init=Modelica.Blocks.Types.Init.InitialOutput
"Type of initialization (no init/steady state/initial state/initial output)";
parameter Real y_start=1 "Initial position of actuator";
final parameter Modelica.Units.SI.PressureDifference dp3Valve_nominal(
displayUnit="Pa")=dpValve_nominal/fraK^2
"Bypass branch valve pressure drop at design conditions";
final parameter Modelica.Units.SI.PressureDifference dp3Fixed_nominal(
displayUnit="Pa")=dpFixed_nominal[2]
"Bypass branch fixed pressure drop at design conditions";
final parameter Modelica.Units.SI.PressureDifference dp3_nominal(
displayUnit="Pa")=dp3Valve_nominal + dp3Fixed_nominal
"Bypass branch total pressure drop at design conditions";
// Variables
Modelica.Units.SI.MassFlowRate m1_flow = port_1.m_flow
"Mass flow rate in direct branch";
Modelica.Units.SI.MassFlowRate m2_flow = -1 * port_2.m_flow
"Mass flow rate in common branch";
Modelica.Units.SI.MassFlowRate m3_flow = port_3.m_flow
"Mass flow rate in bypass branch";
Modelica.Units.SI.PressureDifference dp1(displayUnit="Pa") = port_1.p - port_2.p
"Pressure drop across direct branch";
Modelica.Units.SI.PressureDifference dp3(displayUnit="Pa") = port_3.p - port_2.p
"Pressure drop across bypass branch";
Modelica.Fluid.Interfaces.FluidPort_a port_1(
redeclare final package Medium = Medium,
h_outflow(start=Medium.h_default, nominal=Medium.h_default),
m_flow(min=if (portFlowDirection_1 == Modelica.Fluid.Types.PortFlowDirection.Entering) then 0.0 else -Modelica.Constants.inf,
max=if (portFlowDirection_1== Modelica.Fluid.Types.PortFlowDirection.Leaving) then 0.0 else Modelica.Constants.inf))
"First port, typically inlet";
Modelica.Fluid.Interfaces.FluidPort_b port_2(
redeclare final package Medium = Medium,
h_outflow(start=Medium.h_default, nominal=Medium.h_default),
m_flow(min=if (portFlowDirection_2 == Modelica.Fluid.Types.PortFlowDirection.Entering) then 0.0 else -Modelica.Constants.inf,
max=if (portFlowDirection_2 == Modelica.Fluid.Types.PortFlowDirection.Leaving) then 0.0 else Modelica.Constants.inf))
"Second port, typically outlet";
Modelica.Fluid.Interfaces.FluidPort_a port_3(
redeclare final package Medium=Medium,
h_outflow(start=Medium.h_default, nominal=Medium.h_default),
m_flow(min=if (portFlowDirection_3==Modelica.Fluid.Types.PortFlowDirection.Entering) then 0.0 else -Modelica.Constants.inf,
max=if (portFlowDirection_3==Modelica.Fluid.Types.PortFlowDirection.Leaving) then 0.0 else Modelica.Constants.inf))
"Third port, can be either inlet or outlet";
Buildings.Controls.OBC.CDL.Interfaces.RealInput y(final unit="1")
"Input control signal";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput y_actual
"Actual actuator position";
Actuators.Valves.ThreeWayEqualPercentageLinear valEquLin(
redeclare final package Medium = Medium,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final m_flow_nominal=m_flow_nominal,
final dpValve_nominal=dpValve_nominal,
final rhoStd=rhoStd,
final dpFixed_nominal=dpFixed_nominal,
final R=R,
final delta0=delta0,
final l=l,
final fraK=fraK,
final deltaM=deltaM,
final tau=tau,
final from_dp=from_dp,
final portFlowDirection_1=portFlowDirection_1,
final portFlowDirection_2=portFlowDirection_2,
final portFlowDirection_3=portFlowDirection_3,
final verifyFlowReversal=verifyFlowReversal,
final linearized=linearized,
final energyDynamics=energyDynamics,
final p_start=p_start,
final T_start=T_start,
final X_start=X_start,
final C_start=C_start,
final C_nominal=C_nominal,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final y_start=y_start) if typCha==Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.EqualPercentage
"Three-way valve with equal percentage and linear characteristics";
Actuators.Valves.ThreeWayLinear valLinLin(
redeclare final package Medium = Medium,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final m_flow_nominal=m_flow_nominal,
final dpValve_nominal=dpValve_nominal,
final rhoStd=rhoStd,
final dpFixed_nominal=dpFixed_nominal,
final l=l,
final fraK=fraK,
final deltaM=deltaM,
final tau=tau,
final from_dp=from_dp,
final portFlowDirection_1=portFlowDirection_1,
final portFlowDirection_2=portFlowDirection_2,
final portFlowDirection_3=portFlowDirection_3,
final verifyFlowReversal=verifyFlowReversal,
final linearized=linearized,
final energyDynamics=energyDynamics,
final p_start=p_start,
final T_start=T_start,
final X_start=X_start,
final C_start=C_start,
final C_nominal=C_nominal,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final y_start=y_start) if typCha==Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.Linear
"Three-way valve with linear characteristics";
Actuators.Valves.ThreeWayTable valTab(
redeclare final package Medium = Medium,
final flowCharacteristics1=flowCharacteristics1,
final flowCharacteristics3=flowCharacteristics3,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final m_flow_nominal=m_flow_nominal,
final dpValve_nominal=dpValve_nominal,
final rhoStd=rhoStd,
final dpFixed_nominal=dpFixed_nominal,
final fraK=fraK,
final deltaM=deltaM,
final tau=tau,
final from_dp=from_dp,
final portFlowDirection_1=portFlowDirection_1,
final portFlowDirection_2=portFlowDirection_2,
final portFlowDirection_3=portFlowDirection_3,
final verifyFlowReversal=verifyFlowReversal,
final linearized=linearized,
final energyDynamics=energyDynamics,
final p_start=p_start,
final T_start=T_start,
final X_start=X_start,
final C_start=C_start,
final C_nominal=C_nominal,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final y_start=y_start) if typCha == Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.Table
"Three-way valve with table-specified characteristics";
initial equation
assert(typCha<>Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.PressureIndependent,
"In " + getInstanceName() +
": The pressure independent option is only available for two-way valves.");
equation
connect(y, valEquLin.y);
connect(valEquLin.y_actual, y_actual);
connect(port_3, valEquLin.port_3);
connect(valEquLin.port_2, port_2);
connect(port_1, valEquLin.port_1);
connect(port_1, valLinLin.port_1);
connect(y, valLinLin.y);
connect(valLinLin.port_3, port_3);
connect(y, valTab.y);
connect(valTab.port_1, port_1);
connect(port_3, valTab.port_3);
connect(valTab.port_2, port_2);
connect(valTab.y_actual, y_actual);
connect(valLinLin.y_actual, y_actual);
connect(valLinLin.port_2, port_2);
end ThreeWayValve;
Buildings.Fluid.HydronicConfigurations.Components.TwoWayValve
Container class for two-way valves
Information
This is a container class for two-way valve models from Buildings.Fluid.Actuators.Valves. Note that the models Buildings.Fluid.Actuators.Valves.TwoWayPolynomial and Buildings.Fluid.Actuators.Valves.TwoWayQuickOpening are not represented.
The parameter typCha allows configuring the model
by selecting the valve characteristic to be used based on the enumeration
Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.
Extends from Buildings.Fluid.Interfaces.PartialTwoPortInterface (Partial model transporting fluid between two ports without storing mass or energy), Buildings.Fluid.Interfaces.LumpedVolumeDeclarations (Declarations for lumped volumes), Buildings.Fluid.Actuators.BaseClasses.ValveParameters (Model with parameters for valves).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Real | l | 0.0001 | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Generic | flowCharacteristics | flowCharacteristics(y={0,1},... | Table with flow characteristics |
| Real | R | 50 | Rangeability, R=50...100 typically |
| Real | delta0 | 0.01 | Range of significant deviation from equal percentage law |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] | |
| PressureDifference | dpFixed_nominal | 0 | Pressure drop of pipe and other resistances that are in series [Pa] |
| Flow Coefficient | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av | Av (metric) flow coefficient [m2] | |
| Pressure-flow linearization | |||
| Real | deltaM | 0.02 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Configuration | |||
| ValveCharacteristic | typCha | Buildings.Fluid.HydronicConf... | Valve characteristic |
| 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 | from_dp | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearized | false | = true, use linear relation between m_flow and dp for any flow rate |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Dynamics | |||
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state, must be steady state if energyDynamics is steady state |
| Nominal condition | |||
| Density | rhoStd | Medium.density_pTX(101325, 2... | Inlet density for which valve coefficients are defined [kg/m3] |
| Dynamics | |||
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Real | mSenFac | 1 | Factor for scaling the sensible thermal mass of the volume |
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTime | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | init | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | y_start | 1 | Initial position of actuator |
| 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 |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
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 | y | Input control signal [1] |
| output RealOutput | y_actual | Actual actuator position |
Modelica definition
model TwoWayValve "Container class for two-way valves"
extends Buildings.Fluid.Interfaces.PartialTwoPortInterface;
extends Buildings.Fluid.Interfaces.LumpedVolumeDeclarations(
final massDynamics=energyDynamics,
final mSenFac=1);
extends Buildings.Fluid.Actuators.BaseClasses.ValveParameters(
rhoStd=Medium.density_pTX(101325, 273.15+4, Medium.X_default));
parameter Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic
typCha=Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.EqualPercentage
"Valve characteristic";
parameter Modelica.Units.SI.PressureDifference dpFixed_nominal(
displayUnit="Pa",
min=0) = 0 "Pressure drop of pipe and other resistances that are in series";
parameter Real l(min=1e-10, max=1) = 0.0001
"Valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Buildings.Fluid.Actuators.Valves.Data.Generic flowCharacteristics(
y={0,1},
phi={0.0001,1})
"Table with flow characteristics";
parameter Real R=50
"Rangeability, R=50...100 typically";
parameter Real delta0=0.01
"Range of significant deviation from equal percentage law";
parameter Boolean from_dp = false
"= true, use m_flow = f(dp) else dp = f(m_flow)";
parameter Boolean linearized = false
"= true, use linear relation between m_flow and dp for any flow rate";
parameter Boolean use_inputFilter=true
"= true, if opening is filtered with a 2nd order CriticalDamping filter";
parameter Modelica.Units.SI.Time riseTime=120
"Rise time of the filter (time to reach 99.6 % of an opening step)";
parameter Modelica.Blocks.Types.Init init=Modelica.Blocks.Types.Init.InitialOutput
"Type of initialization (no init/steady state/initial state/initial output)";
parameter Real y_start=1 "Initial position of actuator";
Buildings.Controls.OBC.CDL.Interfaces.RealInput y(final unit="1")
"Input control signal";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput y_actual
"Actual actuator position";
Actuators.Valves.TwoWayEqualPercentage valEqu(
redeclare final package Medium=Medium,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final m_flow_nominal=m_flow_nominal,
final dpValve_nominal=dpValve_nominal,
final rhoStd=rhoStd,
final dpFixed_nominal=dpFixed_nominal,
final R=R,
final delta0=delta0,
final l=l,
final deltaM=deltaM,
final from_dp=from_dp,
final allowFlowReversal=allowFlowReversal,
final linearized=linearized,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final y_start=y_start)
if typCha == Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.EqualPercentage
"Two-way valve with equal percentage characteristic";
Actuators.Valves.TwoWayLinear valLin(
redeclare final package Medium = Medium,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final m_flow_nominal=m_flow_nominal,
final dpValve_nominal=dpValve_nominal,
final rhoStd=rhoStd,
final dpFixed_nominal=dpFixed_nominal,
final l=l,
final deltaM=deltaM,
final from_dp=from_dp,
final allowFlowReversal=allowFlowReversal,
final linearized=linearized,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final y_start=y_start)
if typCha == Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.Linear
"Two-way valve with linear characteristic";
Actuators.Valves.TwoWayTable valTab(
redeclare final package Medium = Medium,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final m_flow_nominal=m_flow_nominal,
final dpValve_nominal=dpValve_nominal,
final rhoStd=rhoStd,
final dpFixed_nominal=dpFixed_nominal,
final deltaM=deltaM,
final from_dp=from_dp,
final allowFlowReversal=allowFlowReversal,
final linearized=linearized,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final y_start=y_start,
final flowCharacteristics=flowCharacteristics)
if typCha == Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.Table
"Two-way valve with table-specified characteristic";
Actuators.Valves.TwoWayPressureIndependent valPre(
redeclare final package Medium=Medium,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final m_flow_nominal=m_flow_nominal,
final dpValve_nominal=dpValve_nominal,
final rhoStd=rhoStd,
final dpFixed_nominal=dpFixed_nominal,
final l=l,
final deltaM=deltaM,
final from_dp=from_dp,
final allowFlowReversal=allowFlowReversal,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final y_start=y_start)
if typCha == Buildings.Fluid.HydronicConfigurations.Types.ValveCharacteristic.PressureIndependent
"Pressure-independent two-way valve";
initial equation
assert(dpFixed_nominal > -Modelica.Constants.eps, "In " + getInstanceName() +
": Model requires dpFixed_nominal >= 0 but received dpFixed_nominal = "
+ String(dpFixed_nominal) + " Pa.");
equation
connect(y, valEqu.y);
connect(valEqu.y_actual, y_actual);
connect(port_a, valEqu.port_a);
connect(valEqu.port_b, port_b);
connect(port_a, valTab.port_a);
connect(port_a, valLin.port_a);
connect(valLin.port_b, port_b);
connect(valLin.y_actual, y_actual);
connect(y, valLin.y);
connect(y, valTab.y);
connect(valTab.port_b, port_b);
connect(valTab.y_actual, y_actual);
connect(port_a, valPre.port_a);
connect(valPre.port_b, port_b);
connect(y, valPre.y);
connect(valPre.y_actual, y_actual);
end TwoWayValve;