Adjust¶

Represents an Adjust (controller) block that iterates a manipulated variable of one simulation object until the controlled variable of another object reaches a specified target value. Uses a bisection or secant numerical method with an optional reference object for relative targets.

DWSIM.UnitOperations.SpecialOps.Adjust
Assembly DWSIM.UnitOperations.dll · Object ← BaseClass ← SpecialOpBaseClass ← Adjust

At a glance¶

Adjust in the example flowsheet

This object has no stream connections; it acts on other objects through their properties.

Example¶

This code runs on every build of this site, and the output below is what it printed.

Python

fs = (Flowsheet.Create("AdjustExample")
      .WithCompound("Water")
      .WithPropertyPackage(PropertyPackages.SteamTables))

feed = (fs.AddMaterialStream("Cold water")
        .At(Q.Celsius(25.0), Q.Bar(2.0))
        .WithMassFlow(Q.KgPerSecond(2.0)))
product = fs.AddMaterialStream("Hot water")
duty = fs.AddEnergyStream("Q-1")

heater = (fs.AddHeater("H-1")
          .WithHeatAdded(Q.Kilowatts(100.0))      # first guess, the adjust changes it
          .ConnectFeed(feed)
          .ConnectProduct(product)
          .ConnectEnergyFeed(duty, 1))          # energy inlet is port 1

def target(obj, prop):
    info = SpecialOpObjectInfo()
    info.ID = obj.Object.Name
    info.Name = obj.Object.GraphicObject.Tag
    info.PropertyName = prop
    info.ObjectType = obj.Object.GetDisplayName()
    return info

builder = fs.AddUnitOperation(ObjectType.OT_Adjust, "ADJ-1")
adj = builder.Object.__implementation__
adj.ManipulatedObjectData = target(heater, "PROP_HT_3")   # heat added (kW)
adj.ControlledObjectData = target(product, "PROP_MS_0")   # temperature
adj.ManipulatedObject = heater.Object
adj.ControlledObject = product.Object
adj.GraphicObject.__implementation__.ConnectedToMv = heater.Object.GraphicObject   # drawing links
adj.GraphicObject.__implementation__.ConnectedToCv = product.Object.GraphicObject
adj.AdjustValue = 273.15 + 80.0         # target, in SI units (K)
adj.Tolerance = 0.01                    # in the flowsheet display units (C here)
adj.SimultaneousAdjust = True           # solved by the flowsheet solver

fs.AutoLayout()
fs.Solve()

h_in = feed.Object.Phases[0].Properties.enthalpy        # kJ/kg
h_out = product.Object.Phases[0].Properties.enthalpy
print(f"Outlet temperature  = {product.TemperatureK - 273.15:.3f} C (target 80 C)")
print(f"Heater duty found   = {heater.HeatDutyKW:.2f} kW")
print(f"Check, m.(h2 - h1)  = {2.0 * (h_out - h_in):.2f} kW")

Output

Outlet temperature  = 80.000 C (target 80 C)
Heater duty found   = 460.10 kW
Check, m.(h2 - h1)  = 460.10 kW

DWSIM 10.2.11.0, generated 2026-10-08.

Properties¶

IDs accepted by GetPropertyValue, SetPropertyValue, the sensitivity analysis, the optimizer, the Adjust block and dynamic events. Units are SI; pass another unit system to GetPropertyValue to get them converted.

ID	Name	Input
`MinVal`	Manipulated Variable Minimum	yes
`MaxVal`	Manipulated Variable Maximum	yes
`AdjustValue`	Set-Point	yes
`Tolerance`	Tolerance (Maximum Error)	yes
`StepSize`	Initial Step Size	yes
`MaximumIterations`	Maximum Iterations	yes

Learn more¶

User guide
- Adjust

API members¶

Public members declared by this class. Inherited members are documented on the base classes.

Constructors¶

Adjust(): Initializes a new default instance of the Adjust class.

Initializes a new default instance of the Adjust class.

C#VB.NET

public Adjust()

Public Sub New()

Adjust(string, string): Initializes a new instance of the Adjust class with a name and description.

Initializes a new instance of the Adjust class with a name and description.

Parameter	Type	Description
`name`	`String`	The display name of the adjust block.
`description`	`String`	A brief description of the block.

C#VB.NET

public Adjust(string name, string description)

Public Sub New(name As String, description As String)

Properties¶

ControlledObject: Gets or sets the controlled simulation object instance (not serialized).

Gets or sets the controlled simulation object instance (not serialized).

C#VB.NET

public BaseClass ControlledObject { get; set; }

Public Property ControlledObject As BaseClass

ControlledVariable: Gets or sets the property identifier of the variable to be controlled (driven to the target value).

Gets or sets the property identifier of the variable to be controlled (driven to the target value).

C#VB.NET

public string ControlledVariable { get; set; }

Public Property ControlledVariable As String

CvOk: Gets or sets whether the controlled variable object and property are correctly configured.

Gets or sets whether the controlled variable object and property are correctly configured.

C#VB.NET

public bool CvOk { get; set; }

Public Property CvOk As Boolean

InitialEstimate: Gets or sets the optional initial estimate for the manipulated variable used to seed the solver.

Gets or sets the optional initial estimate for the manipulated variable used to seed the solver.

C#VB.NET

public double? InitialEstimate { get; set; }

Public Property InitialEstimate As Double?

ManipulatedObject: Gets or sets the manipulated simulation object instance (not serialized).

Gets or sets the manipulated simulation object instance (not serialized).

C#VB.NET

public BaseClass ManipulatedObject { get; set; }

Public Property ManipulatedObject As BaseClass

ManipulatedVariable: Gets or sets the property identifier of the variable to be manipulated by the solver.

Gets or sets the property identifier of the variable to be manipulated by the solver.

C#VB.NET

public string ManipulatedVariable { get; set; }

Public Property ManipulatedVariable As String

MaximumIterations: Gets or sets the maximum number of solver iterations allowed before declaring non-convergence.

Gets or sets the maximum number of solver iterations allowed before declaring non-convergence.

C#VB.NET

public int MaximumIterations { get; set; }

Public Property MaximumIterations As Integer

MaxVal: Gets or sets the optional upper bound for the manipulated variable search range.

Gets or sets the optional upper bound for the manipulated variable search range.

C#VB.NET

public double? MaxVal { get; set; }

Public Property MaxVal As Double?

MinVal: Gets or sets the optional lower bound for the manipulated variable search range.

Gets or sets the optional lower bound for the manipulated variable search range.

C#VB.NET

public double? MinVal { get; set; }

Public Property MinVal As Double?

MobileCompatible: Gets a value indicating whether this block is compatible with the DWSIM mobile interface.

Gets a value indicating whether this block is compatible with the DWSIM mobile interface.

C#VB.NET

public override bool MobileCompatible { get; }

Public Overrides ReadOnly Property MobileCompatible As Boolean

MvOk: Gets or sets whether the manipulated variable object and property are correctly configured.

Gets or sets whether the manipulated variable object and property are correctly configured.

C#VB.NET

public bool MvOk { get; set; }

Public Property MvOk As Boolean

ReferenceObject: Gets or sets the optional reference simulation object instance (not serialized).

Gets or sets the optional reference simulation object instance (not serialized).

C#VB.NET

public BaseClass ReferenceObject { get; set; }

Public Property ReferenceObject As BaseClass

ReferenceVariable: Gets or sets the property identifier of the optional reference variable used as a relative target basis.

Gets or sets the property identifier of the optional reference variable used as a relative target basis.

C#VB.NET

public string ReferenceVariable { get; set; }

Public Property ReferenceVariable As String

RvOk: Gets or sets whether the reference variable object and property are correctly configured.

Gets or sets whether the reference variable object and property are correctly configured.

C#VB.NET

public bool RvOk { get; set; }

Public Property RvOk As Boolean

SolvingMethodSelf: Gets or sets the solving method index used by this block (0 = bisection, 1 = secant, etc.).

Gets or sets the solving method index used by this block (0 = bisection, 1 = secant, etc.).

C#VB.NET

public int SolvingMethodSelf { get; set; }

Public Property SolvingMethodSelf As Integer

Status: Gets or sets a status message describing the outcome of the last calculation attempt.

Gets or sets a status message describing the outcome of the last calculation attempt.

C#VB.NET

public string Status { get; set; }

Public Property Status As String

StepSize: Gets or sets the step size used by the initial perturbation of the manipulated variable.

Gets or sets the step size used by the initial perturbation of the manipulated variable.

C#VB.NET

public double StepSize { get; set; }

Public Property StepSize As Double

Methods¶

CloneXML(): Creates a deep copy of this adjust block via XML serialization.

Creates a deep copy of this adjust block via XML serialization.

C#VB.NET

public override object CloneXML()

Public Overrides Function CloneXML() As Object

CloseEditForm(): Closes and disposes the editing form for this adjust block if it is open.

Closes and disposes the editing form for this adjust block if it is open.

C#VB.NET

public override void CloseEditForm()

Public Overrides Sub CloseEditForm()

DisplayEditForm(): Opens or activates the editing form for this adjust block.

Opens or activates the editing form for this adjust block.

C#VB.NET

public override void DisplayEditForm()

Public Overrides Sub DisplayEditForm()

GetDisplayDescription(): Returns the localized display description for the adjust block type.

Returns the localized display description for the adjust block type.

C#VB.NET

public override string GetDisplayDescription()

Public Overrides Function GetDisplayDescription() As String

GetDisplayName(): Returns the localized display name for the adjust block type.

Returns the localized display name for the adjust block type.

C#VB.NET

public override string GetDisplayName()

Public Overrides Function GetDisplayName() As String

GetIconBitmapBytes(): Returns the raw bytes of the adjust block icon image resource.

Returns the raw bytes of the adjust block icon image resource.

C#VB.NET

public override byte[] GetIconBitmapBytes()

Public Overrides Function GetIconBitmapBytes() As Byte()

GetProperties(PropertyType): Returns the list of property identifiers available for this adjust block.

Returns the list of property identifiers available for this adjust block.

Parameter	Type	Description
`proptype`	`PropertyType`	The type of properties to retrieve.

C#VB.NET

public override string[] GetProperties(PropertyType proptype)

Public Overrides Function GetProperties(proptype As PropertyType) As String()

GetPropertyDescription(string): Readable names for the property identifiers, which are the .NET property names.

Readable names for the property identifiers, which are the .NET property names.

Parameter	Type	Description
`prop`	`String`

C#VB.NET

public override string GetPropertyDescription(string prop)

Public Overrides Function GetPropertyDescription(prop As String) As String

GetPropertyUnit(string, IUnitsOfMeasure): Returns the unit string for the specified property (always an empty string for this block).

Returns the unit string for the specified property (always an empty string for this block).

Parameter	Type	Description
`prop`	`String`	The property identifier string.
`su`	`IUnitsOfMeasure`	The unit system to use; defaults to SI if not provided.

C#VB.NET

public override string GetPropertyUnit(string prop, IUnitsOfMeasure su = null)

Public Overrides Function GetPropertyUnit(prop As String, su As IUnitsOfMeasure = Nothing) As String

GetPropertyValue(string, IUnitsOfMeasure): Returns the value of the specified property.

Returns the value of the specified property.

Parameter	Type	Description
`prop`	`String`	The property identifier or name string.
`su`	`IUnitsOfMeasure`	The unit system to use; defaults to SI if not provided.

C#VB.NET

public override object GetPropertyValue(string prop, IUnitsOfMeasure su = null)

Public Overrides Function GetPropertyValue(prop As String, su As IUnitsOfMeasure = Nothing) As Object

LoadData(List<XElement>): Restores the adjust block state from a list of XML elements.

Restores the adjust block state from a list of XML elements.

Parameter	Type	Description
`data`	`List<XElement>`	The list of `XElement` objects containing the serialized state.

C#VB.NET

public override bool LoadData(List<XElement> data)

Public Overrides Function LoadData(data As List(Of XElement)) As Boolean

PerformAdjust(string, double, double): Solves the adjust with a numerical root finder: changes the manipulated variable and re-solves the flowsheet until...

Solves the adjust with a numerical root finder: changes the manipulated variable and re-solves the flowsheet until the controlled variable matches the target value (or the referenced variable plus the target offset). If the solver fails, the manipulated variable is restored to its initial value and the exception is rethrown.

Parameter	Type	Description
`solver`	`String`	Root finder to use (case-insensitive): "secant", "brent", "newton" or "ipopt".
`minval`	`Double`	Optional lower bound of the manipulated variable, in the flowsheet's selected units. Used by the Brent and IPOPT solvers; when both bounds are given, the secant solver takes its limits from `MinVal` and `MaxVal`.
`maxval`	`Double`	Optional upper bound of the manipulated variable, in the flowsheet's selected units, used in the same way as minval.

C#VB.NET

public double PerformAdjust(string solver, double minval = NaN, double maxval = NaN)

Public Function PerformAdjust(solver As String, minval As Double = NaN, maxval As Double = NaN) As Double

SaveData(): Serializes the adjust block state to a list of XML elements for persistence.

Serializes the adjust block state to a list of XML elements for persistence.

C#VB.NET

public override List<XElement> SaveData()

Public Overrides Function SaveData() As List(Of XElement)

SetPropertyValue(string, object, IUnitsOfMeasure): Sets the value of the specified property.

Sets the value of the specified property.

Parameter	Type	Description
`prop`	`String`	The property identifier or name string.
`propval`	`Object`	The new value to assign.
`su`	`IUnitsOfMeasure`	The unit system of the supplied value; defaults to SI if not provided.

C#VB.NET

public override bool SetPropertyValue(string prop, object propval, IUnitsOfMeasure su = null)

Public Overrides Function SetPropertyValue(prop As String, propval As Object, su As IUnitsOfMeasure = Nothing) As Boolean

UpdateEditForm(): Refreshes the displayed data in the editing form if it is currently open.

Refreshes the displayed data in the editing form if it is currently open.

C#VB.NET

public override void UpdateEditForm()

Public Overrides Sub UpdateEditForm()

Fields¶

f: The classic (WinForms) editor window open for this logical block, if any.

The classic (WinForms) editor window open for this logical block, if any. Not saved with the flowsheet.

C#VB.NET

public object f

Public f As Object