blockMixingValveControl
Mixing valve controller
Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Information
This model implements a generic controller for a three-way mixing valve. Three operating modes are supported:
- Heating: the controller tracks a minimum supply temperature.
- Cooling: the controller tracks a maximum supply temperature.
-
Change-over: the controller tracks either a minimum or a maximum
supplied temperature depending on the actual value of the integer input
modChaOve(1 for heating, 2 for cooling). The model instantiates only one PI block to limit the number of state variables in large models. Therefore the PI gain is independent from the change-over mode: the reverse action is modeled by taking the opposite value of the PI block output. Eventually the integral part is reset whenever the change-over mode is switched.
See Buildings.DHC.Loads.BaseClasses.Controls.Validation.MixingValveControl for a simulation with change-over.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.DHC.Loads.BaseClasses.Types.DistributionType | typDis | Buildings.DHC.Loads.BaseClasses.Types.DistributionType.HeatingWater | Type of distribution system |
| Real | k | 0.1 | Gain of controller |
| Real | Ti | 10 | Time constant of integrator block |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.IntegerInput | modChaOve | Operating mode in change-over (1 for heating, 2 for cooling) | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | TSupSet | Supply temperature set point | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | TSupMes | Supply temperature (measured) | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | yVal | Valve control signal |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | zer | Zero constant | |
| Buildings.Controls.OBC.CDL.Integers.GreaterEqualThreshold | toBoo | Conversion to boolean (true if cooling mode) | |
| Buildings.Controls.OBC.CDL.Reals.PIDWithReset | resConTSup | PI controller tracking supply temperature | |
| Buildings.Controls.OBC.CDL.Reals.PID | conTSup | PI controller tracking supply temperature | |
| Buildings.Controls.OBC.CDL.Reals.Min | negPar | Negative part of control signal | |
| Buildings.Controls.OBC.CDL.Reals.Max | posPar | Positive part of control signal | |
| Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter | opp | Opposite value | |
| Buildings.Controls.OBC.CDL.Reals.Switch | swi | Logical switch | |
| Buildings.Controls.OBC.CDL.Logical.Sources.Constant | fixMod | Fixed operating mode | |
| Buildings.Controls.OBC.CDL.Integers.Change | cha | Evaluate the integer input u to check if its value changes |
Revisions
-
February 21, 2020, by Antoine Gautier:
First implementation.