Buildings.Fluids.Actuators.Valves

Information

Package Content

Name	Description
ThreeWayEqualPercentageLinear	Three way valve with equal percentage and linear characteristics
ThreeWayLinear	Three way valve with linear characteristics
TwoWayEqualPercentage	Two way valve with linear flow characteristics
TwoWayLinear	Two way valve with linear flow characteristics
TwoWayQuickOpening	Two way valve with linear flow characteristics

Buildings.Fluids.Actuators.Valves.ThreeWayEqualPercentageLinear

Information

Three way valve with equal percentage characteristics between port_1 and port_2 and linear opening characteristic between port_1 and port_2. Such opening characteristics were typical for valves from Landis & Gyr (now Siemens).

This model is based on the partial valve models PartialThreeWayValve and PartialTwoWayValve. See PartialThreeWayValve for the implementation of the three way valve and see PartialTwoWayValve for the implementation of the leakage flow or the regularization near the origin.

Parameters

Type	Name	Default	Description
replaceable package Medium		PartialMedium	Fluid medium model
Real	k_SI		Flow coefficient for fully open valve in SI units, k=m_flow/sqrt(dp) [(kg*m)^(1/2)]
Real	fraK	0.7	Fraction k_SI(port_1->port_2)/k_SI(port_3->port_2)
Real	l[2]	{0,0}	Valve leakage, l=Cv(y=0)/Cvs
Real	R	50	Rangeability, R=50...100 typically
Real	delta0	0.01	Range of significant deviation from equal percentage law
Pressure-flow linearization
Real	deltaM	0.02	Fraction of nominal flow rate where linearization starts, if y=1
Pressure	dp0	6000	Nominal pressure drop [Pa]
Advanced
Boolean	from_dp	true	= true, use m_flow = f(dp) else dp = f(m_flow)
Temp	flowDirection	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_1 -> port_2) or bidirectional flow component
Boolean	linearized[2]	{false,false}	= true, use linear relation between m_flow and dp for any flow rate

Connectors

Type	Name	Description
FluidPort_b	port_1
FluidPort_b	port_2
FluidPort_b	port_3
input RealInput	y	Damper position (0: closed, 1: open)

Modelica definition

model ThreeWayEqualPercentageLinear 
  "Three way valve with equal percentage and linear characteristics" 
    extends BaseClasses.PartialThreeWayValve(
      redeclare TwoWayEqualPercentage res1(
      redeclare package Medium = Medium,
      k_SI=k_SI,
      l=l[1],
      deltaM=deltaM,
      dp0=dp0,
      flowDirection=flowDirection,
      from_dp=from_dp,
      linearized=linearized[1],
      R=R,
      delta0=delta0),
      redeclare TwoWayLinear res3(
      redeclare package Medium = Medium,
      k_SI=fraK*k_SI,
      l=l[2],
      deltaM=deltaM,
      dp0=dp0,
      flowDirection=flowDirection,
      from_dp=from_dp,
      linearized=linearized[2]));
  parameter Real R = 50 "Rangeability, R=50...100 typically";
  parameter Real delta0 = 0.01 
    "Range of significant deviation from equal percentage law";
  
equation 
  connect(inv.y, res3.y);
  connect(y, inv.u2);
  connect(y, res1.y);
end ThreeWayEqualPercentageLinear;

Buildings.Fluids.Actuators.Valves.ThreeWayLinear

Information

Three way valve with linear opening characteristic.

This model is based on the partial valve models PartialThreeWayValve and PartialTwoWayValve. See PartialThreeWayValve for the implementation of the three way valve and see PartialTwoWayValve for the implementation of the leakage flow or the regularization near the origin.

Parameters

Type	Name	Default	Description
replaceable package Medium		PartialMedium	Fluid medium model
Real	k_SI		Flow coefficient for fully open valve in SI units, k=m_flow/sqrt(dp) [(kg*m)^(1/2)]
Real	fraK	0.7	Fraction k_SI(port_1->port_2)/k_SI(port_3->port_2)
Real	l[2]	{0,0}	Valve leakage, l=Cv(y=0)/Cvs
Pressure-flow linearization
Real	deltaM	0.02	Fraction of nominal flow rate where linearization starts, if y=1
Pressure	dp0	6000	Nominal pressure drop [Pa]
Advanced
Boolean	from_dp	true	= true, use m_flow = f(dp) else dp = f(m_flow)
Temp	flowDirection	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_1 -> port_2) or bidirectional flow component
Boolean	linearized[2]	{false,false}	= true, use linear relation between m_flow and dp for any flow rate

Connectors

Type	Name	Description
FluidPort_b	port_1
FluidPort_b	port_2
FluidPort_b	port_3
input RealInput	y	Damper position (0: closed, 1: open)

Modelica definition

model ThreeWayLinear "Three way valve with linear characteristics" 
    extends BaseClasses.PartialThreeWayValve(
      redeclare TwoWayLinear res1(
      redeclare package Medium = Medium,
      k_SI=k_SI,
      l=l[1],
      deltaM=deltaM,
      dp0=dp0,
      flowDirection=flowDirection,
      from_dp=from_dp,
      linearized=linearized[1]),
      redeclare TwoWayLinear res3(
      redeclare package Medium = Medium,
      k_SI=fraK*k_SI,
      l=l[2],
      deltaM=deltaM,
      dp0=dp0,
      flowDirection=flowDirection,
      from_dp=from_dp,
      linearized=linearized[2]));
  
equation 
  connect(inv.y, res3.y);
  connect(y, inv.u2);
  connect(y, res1.y);
end ThreeWayLinear;

Buildings.Fluids.Actuators.Valves.TwoWayEqualPercentage

Information

Two way valve with an equal percentage valve opening characteristic.

This model is based on the partial valve model PartialTwoWayValve. Check this model for more information, such as the leakage flow or regularization near the origin.

Parameters

Type	Name	Default	Description
replaceable package Medium		PartialMedium	Medium in the component
Real	k_SI		Flow coefficient for fully open valve in SI units, k=m_flow/sqrt(dp) [(kg*m)^(1/2)]
Real	l	0.005	Valve leakage, l=Cv(y=0)/Cvs
Real	R	50	Rangeability, R=50...100 typically
Real	delta0	0.01	Range of significant deviation from equal percentage law
Initialization
MassFlowRate	m_flow		Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s]
Pressure	dp		Pressure difference between port_a and port_b [Pa]
Pressure-flow linearization
Real	deltaM	0.02	Fraction of nominal flow rate where linearization starts, if y=1
Pressure	dp0	6000	Nominal pressure drop [Pa]
Advanced
Temp	flowDirection	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component
Boolean	from_dp	true	= 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

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	Damper position (0: closed, 1: open)

Modelica definition

model TwoWayEqualPercentage 
  "Two way valve with linear flow characteristics" 
  extends BaseClasses.PartialTwoWayValve;
  parameter Real R = 50 "Rangeability, R=50...100 typically";
  parameter Real delta0 = 0.01 
    "Range of significant deviation from equal percentage law";
initial equation 
 assert(l < 1/R, "Wrong parameters in valve model.\n"
               + "  Rangeability R = " + realString(R) +  "\n"
               + "  Leakage flow l = " + realString(l) +  "\n"
               + "  Must have l < 1/R = " + realString(1/R));
  
equation 
  phi = Buildings.Fluids.Actuators.BaseClasses.equalPercentage(y, R, l, delta0);
end TwoWayEqualPercentage;

Buildings.Fluids.Actuators.Valves.TwoWayLinear

Information

Two way valve with linear opening characteristic.

This model is based on the partial valve model PartialTwoWayValve. Check this model for more information, such as the leakage flow or regularization near the origin.

Parameters

Type	Name	Default	Description
replaceable package Medium		PartialMedium	Medium in the component
Real	k_SI		Flow coefficient for fully open valve in SI units, k=m_flow/sqrt(dp) [(kg*m)^(1/2)]
Real	l	0.005	Valve leakage, l=Cv(y=0)/Cvs
Initialization
MassFlowRate	m_flow		Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s]
Pressure	dp		Pressure difference between port_a and port_b [Pa]
Pressure-flow linearization
Real	deltaM	0.02	Fraction of nominal flow rate where linearization starts, if y=1
Pressure	dp0	6000	Nominal pressure drop [Pa]
Advanced
Temp	flowDirection	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component
Boolean	from_dp	true	= 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

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	Damper position (0: closed, 1: open)

Modelica definition

model TwoWayLinear "Two way valve with linear flow characteristics" 
  extends BaseClasses.PartialTwoWayValve;
  
equation 
  phi = l + y * (1 - l);
end TwoWayLinear;

Buildings.Fluids.Actuators.Valves.TwoWayQuickOpening

Information

Two way valve with a power function for the valve opening characteristic. Valves that need to open quickly typically have such a valve characteristics.

This model is based on the partial valve model PartialTwoWayValve. Check this model for more information, such as the leakage flow or regularization near the origin.

Parameters

Type	Name	Default	Description
replaceable package Medium		PartialMedium	Medium in the component
Real	k_SI		Flow coefficient for fully open valve in SI units, k=m_flow/sqrt(dp) [(kg*m)^(1/2)]
Real	l	0.005	Valve leakage, l=Cv(y=0)/Cvs
Real	alp	2	Parameter for valve characteristics, alp>0
Real	delta0	0.01	Range of significant deviation from power law
Initialization
MassFlowRate	m_flow		Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s]
Pressure	dp		Pressure difference between port_a and port_b [Pa]
Pressure-flow linearization
Real	deltaM	0.02	Fraction of nominal flow rate where linearization starts, if y=1
Pressure	dp0	6000	Nominal pressure drop [Pa]
Advanced
Temp	flowDirection	Modelica_Fluid.Types.FlowDir...	Unidirectional (port_a -> port_b) or bidirectional flow component
Boolean	from_dp	true	= 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

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	Damper position (0: closed, 1: open)

Modelica definition

model TwoWayQuickOpening 
  "Two way valve with linear flow characteristics" 
  extends BaseClasses.PartialTwoWayValve;
  parameter Real alp = 2 "Parameter for valve characteristics, alp>0";
  parameter Real delta0 = 0.01 "Range of significant deviation from power law";
protected 
   parameter Real alpInv = 1/alp;
equation 
  phi = l + Modelica_Fluid.Utilities.regPow(y, alpInv, delta0) * (1 - l);
end TwoWayQuickOpening;