modelDamper

Multiple-configuration damper

Extends from Buildings.Fluid.Interfaces.PartialTwoPortInterface (Partial model with two ports and declaration of quantities that are used by many models).

Information

This is a container model that can be used to represent a variety of dampers. The supported damper types are described in the enumeration Buildings.Templates.Components.Types.Damper.

Control points

The following input and output points are available.

For modulating dampers:

The damper opening is modulated with a fractional opening signal y (real).
y = 0 corresponds to fully closed. y = 1 corresponds to fully open.
The actual damper position y_actual (real) is returned.
y_actual = 0 corresponds to fully closed. y_actual = 1 corresponds to fully open.

For pressure-independent dampers:

The airflow setpoint is modulated with a fractional airflow signal y (real).
y = 0 corresponds to zero airflow. y = 1 corresponds to the maximum airflow.
The actual damper position y_actual (real) is returned.
y_actual = 0 corresponds to fully closed. y_actual = 1 corresponds to fully open.

For two-position dampers:

The damper is commanded open with a Boolean signal y1.
y1 = 0 corresponds to fully closed. y1 = 1 corresponds to fully open.
The open end switch status y1_actual and closed end switch status y0_actual (Booleans) are returned.
y1_actual = false corresponds to fully closed. y1_actual = true corresponds to fully open. And the opposite for y0_actual.

Model parameters

The design operating point is specified with an instance of Buildings.Templates.Components.Data.Damper.

Parameters

Type	Name	Default	Description
Buildings.Templates.Components.Data.Damper	dat		Design and operating parameters
Modelica.Units.SI.PressureDifference	dp_nominal	dat.dp_nominal	Damper pressure drop
Modelica.Units.SI.PressureDifference	dpFixed_nominal	dat.dpFixed_nominal	Pressure drop of duct and resistances other than the damper in series, at nominal mass flow rate
Assumptions
Boolean	allowFlowReversal (from PartialTwoPort)	true	= false to simplify equations, assuming, but not enforcing, no flow reversal
Nominal condition
Modelica.Units.SI.MassFlowRate	m_flow_nominal (from PartialTwoPortInterface)		Nominal mass flow rate
Advanced
Modelica.Units.SI.MassFlowRate	m_flow_small (from PartialTwoPortInterface)	1E-4*abs(m_flow_nominal)	Small mass flow rate for regularization of zero flow
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
Advanced › Diagnostics
Boolean	show_T (from PartialTwoPortInterface)	false	= true, if actual temperature at port is computed
Configuration
Buildings.Templates.Components.Types.Damper	typ		Equipment type
Dynamics › Time needed to open or close valve
Boolean	use_strokeTime	true	Set to true to continuously open and close valve
Modelica.Units.SI.Time	strokeTime	120	Time needed to open or close valve
Modelica.Blocks.Types.Init	init	Modelica.Blocks.Types.Init.InitialOutput	Type of initialization (no init/steady state/initial state/initial output)
Real	y_start	1	Initial position of actuator
Graphics
Buildings.Templates.Components.Types.DamperBlades	typBla	if typ == Buildings.Templates.Components.Types.Damper.TwoPosition then Buildings.Templates.Components.Types.DamperBlades.Opposed elseif typ == Buildings.Templates.Components.Types.Damper.PressureIndependent then Buildings.Templates.Components.Types.DamperBlades.VAV else Buildings.Templates.Components.Types.DamperBlades.Parallel	Type of blades
Integer	text_rotation	0	Text rotation angle in icon layer
Boolean	text_flip	false	True to flip text horizontally in icon layer

Connectors

Type	Name	Description
Modelica.Fluid.Interfaces.FluidPort_a	port_a (from PartialTwoPort)	Fluid connector a (positive design flow direction is from port_a to port_b)
Modelica.Fluid.Interfaces.FluidPort_b	port_b (from PartialTwoPort)	Fluid connector b (positive design flow direction is from port_a to port_b)
Buildings.Templates.Components.Interfaces.Bus	bus	Control bus

Components

Type	Name	Default	Description
Modelica.Units.SI.MassFlowRate	m_flow (from PartialTwoPortInterface)	port_a.m_flow	Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction)
Modelica.Units.SI.PressureDifference	dp (from PartialTwoPortInterface)	port_a.p - port_b.p	Pressure difference between port_a and port_b
Medium.ThermodynamicState	sta_a (from PartialTwoPortInterface)	if allowFlowReversal then Medium.setState_phX(port_a.p, noEvent(actualStream(port_a.h_outflow)), noEvent(actualStream(port_a.Xi_outflow))) else Medium.setState_phX(port_a.p, noEvent(inStream(port_a.h_outflow)), noEvent(inStream(port_a.Xi_outflow)))	Medium properties in port_a
Medium.ThermodynamicState	sta_b (from PartialTwoPortInterface)	if allowFlowReversal then Medium.setState_phX(port_b.p, noEvent(actualStream(port_b.h_outflow)), noEvent(actualStream(port_b.Xi_outflow))) else Medium.setState_phX(port_b.p, noEvent(port_b.h_outflow), noEvent(port_b.Xi_outflow))	Medium properties in port_b
Buildings.Fluid.Actuators.Dampers.Exponential	exp		Damper with exponential characteristic
Buildings.Fluid.Actuators.Dampers.PressureIndependent	ind		Pressure independent damper
Buildings.Fluid.FixedResistances.PressureDrop	non		No damper
Buildings.Controls.OBC.CDL.Conversions.BooleanToReal	y1		Two-position signal
Modelica.Blocks.Routing.RealPassThrough	y		Modulating signal
Buildings.Controls.OBC.CDL.Reals.LessThreshold	y0_actual		Closed end switch status
Buildings.Controls.OBC.CDL.Reals.GreaterThreshold	y1_actual		Open end switch status
Modelica.Blocks.Routing.RealPassThrough	y_actual		Position feedback

Revisions

May 7, 2025, by Antoine Gautier:
Replaced direct fluid pass-through with fixed resistance.
This is for #4227.
September 27, 2023, by Antoine Gautier:
First implementation.