Buildings.Fluid.Actuators.Valves

Package with valve models

Information

Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).

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
TwoWayTable	Two way valve with linear flow characteristics
Data	Data files for valves
Examples	Collection of models that illustrate model use and test models

Buildings.Fluid.Actuators.Valves.ThreeWayEqualPercentageLinear

Three way valve with equal percentage and linear characteristics

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 Buildings.Fluid.Actuators.BaseClasses.PartialThreeWayValve and Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve. See Buildings.Fluid.Actuators.BaseClasses.PartialThreeWayValve for the implementation of the three way valve and see Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve for the implementation of the regularization near the origin.

Extends from BaseClasses.PartialThreeWayValve (Partial three way valve).

Parameters

Connectors

Modelica definition

Buildings.Fluid.Actuators.Valves.ThreeWayLinear

Three way valve with linear characteristics

Information

Three way valve with linear opening characteristic.

This model is based on the partial valve models Buildings.Fluid.Actuators.BaseClasses.PartialThreeWayValve and Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve. See Buildings.Fluid.Actuators.BaseClasses.PartialThreeWayValve for the implementation of the three way valve and see Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve for the implementation of the regularization near the origin.

Extends from BaseClasses.PartialThreeWayValve (Partial three way valve).

Parameters

Connectors

Modelica definition

Buildings.Fluid.Actuators.Valves.TwoWayEqualPercentage

Two way valve with linear flow characteristics

Information

Two way valve with an equal percentage valve opening characteristic.

This model is based on the partial valve model Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve. Check this model for more information, such as the regularization near the origin.

Extends from BaseClasses.PartialTwoWayValve (Partial model for a two way valve).

Parameters

Connectors

Modelica definition

Buildings.Fluid.Actuators.Valves.TwoWayLinear

Two way valve with linear flow characteristics

Information

Two way valve with linear opening characteristic.

This model is based on the partial valve model Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve. Check this model for more information, such as the regularization near the origin.

Extends from BaseClasses.PartialTwoWayValve (Partial model for a two way valve).

Parameters

Connectors

Modelica definition

Buildings.Fluid.Actuators.Valves.TwoWayQuickOpening

Two way valve with linear flow characteristics

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 Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve. Check this model for more information, such as the regularization near the origin.

Extends from BaseClasses.PartialTwoWayValve (Partial model for a two way valve).

Parameters

Connectors

Modelica definition

Buildings.Fluid.Actuators.Valves.TwoWayTable

Two way valve with linear flow characteristics

Information

Two way valve with opening characteristic that is configured through a table.

The mass flow rate for the fully open valve is determined based on the value of the parameter CvData. For the different valve positions y ∈ [0, 1], this nominal flow rate is scaled by the values of the parameter flowCharacteristics. The parameter flowCharacteristics declares a table of the form

where l = K_v(y=0)/K_v(y=1) > 0 is the valve leakage. The first row is the valve opening, and the second row is the mass flow rate, relative to the mass flow rate of the fully open valve, under the assumption of a constant pressure difference across the valve. A suggested value for the valve leakage is l=0.0001. If l = 0, then this model will replace it with l = 10^-8 for numerical reasons. For example, if a valve has K_v=0.5 [m³/h/bar^1/2] and a linear opening characteristics and a valve leakage of l=0.0001, then one would set

 CvData=Buildings.Fluid.Types.CvTypes.Kv
 Kv = 0.5
 flowCharacteristics(y={0,1}, phi={0.0001,1})
 

Note, however, that Buildings.Fluid.Actuators.Valves.TwoWayLinear provides a more efficient implementation for this simple case.

The parameter flowCharacteristics must meet the following requirements, otherwise the model stops with an error:

• The arrays in flowCharacteristics.y and flowCharacteristics.phi must be strictly monotonic increasing.
• The first value must satisfy flowCharacteristics.y[1]=0, and flowCharacteristics.phi[1] must be equal to the leakage flow rate, which must be bigger than zero. Otherwise, a default value of 1E-8 is used.
• The last values must satisfy flowCharacteristics.y[end]=1 and flowCharacteristics.phi[end]=1.

This model is based on the partial valve model Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve. Check this model for more information, such as the regularization near the origin.

For an example that specifies an opening characteristics, see Buildings.Fluid.Actuators.Valves.Examples.TwoWayValveTable.

Extends from BaseClasses.PartialTwoWayValve (Partial model for a two way valve).

Parameters

Connectors

Modelica definition