Plug Flow Reactor — IDAES v1.1.1 (2024)

Degrees of Freedom¶

PFRs generally have at least 2 degrees of freedom.

Typical fixed variables are:

• 2 of reactor length, area and volume.

Model Structure¶

The core PFR unit model consists of a single ControlVolume1DBlock (named control_volume) with one Inlet Port (named inlet) and one Outlet Port (named outlet).

Variables¶

PFR units add the following additional Variables:

Constraints¶

PFR units write the following additional Constraints at all points in the spatial domain:

\[X_{t,x,r} = A \times r_{t,x,r}\]

where \(X_{t,x,r}\) is the extent of reaction of reaction \(r\) at point \(x\) and time \(t\), \(A\) is the cross-sectional area of the reactor and \(r_{t,r}\) is the volumetric rate of reaction of reaction \(r\) at point \(x\) and time \(t\) (from the outlet StateBlock).

PFR Class¶

class idaes.unit_models.plug_flow_reactor.PFR(*args, **kwargs)¶

Parameters:

rule (function) – A rule function or None. Default rule calls build(). concrete (bool) – If True, make this a toplevel model. Default - False. ctype (str) – Pyomo ctype of the block. Default - “Block” default (dict) – Default ProcessBlockData config Keys dynamic Indicates whether this model will be dynamic or not,default = useDefault. Valid values: {useDefault - get flag from parent (default = False),True - set as a dynamic model, False - set as asteady-state model.} has_holdup Indicates whether holdup terms should be constructed ornot. Must be True if dynamic = True, default - False.Valid values: { True - construct holdup terms,False - do not construct holdup terms} material_balance_type Indicates what type of mass balance should be constructed,default - MaterialBalanceType.componentPhase. Validvalues: { MaterialBalanceType.none - excludematerial balances, MaterialBalanceType.componentPhase- use phase component balances,MaterialBalanceType.componentTotal - use totalcomponent balances, MaterialBalanceType.elementTotal -use total element balances, MaterialBalanceType.total- use total material balance.} energy_balance_type Indicates what type of energy balance should beconstructed, default -EnergyBalanceType.enthalpyTotal. Valid values: {EnergyBalanceType.none - exclude energy balances,EnergyBalanceType.enthalpyTotal - single ethalpybalance for material, EnergyBalanceType.enthalpyPhase- ethalpy balances for each phase,EnergyBalanceType.energyTotal - single energy balancefor material, EnergyBalanceType.energyPhase - energybalances for each phase.} momentum_balance_type Indicates what type of momentum balance should beconstructed, default -MomentumBalanceType.pressureTotal. Valid values: {MomentumBalanceType.none - exclude momentum balances,MomentumBalanceType.pressureTotal - single pressurebalance for material,MomentumBalanceType.pressurePhase - pressure balancesfor each phase, MomentumBalanceType.momentumTotal -single momentum balance for material,MomentumBalanceType.momentumPhase - momentum balancesfor each phase.} has_equilibrium_reactions Indicates whether terms for equilibrium controlledreactions should be constructed, default - True.Valid values: { True - include equilibriumreaction terms, False - exclude equilibrium reactionterms.} has_phase_equilibrium Indicates whether terms for phase equilibrium should beconstructed, default = False. Valid values: {True - include phase equilibrium terms False -exclude phase equilibrium terms.} has_heat_of_reaction Indicates whether terms for heat of reaction terms shouldbe constructed, default - False. Valid values: {True - include heat of reaction terms, False -exclude heat of reaction terms.} has_heat_transfer Indicates whether terms for heat transfer should beconstructed, default - False. Valid values: {True - include heat transfer terms, False -exclude heat transfer terms.} has_pressure_change Indicates whether terms for pressure change should beconstructed, default - False. Valid values: {True - include pressure change terms, False -exclude pressure change terms.} property_package Property parameter object used to define propertycalculations, default - useDefault. Valid values:{ useDefault - use default package from parent modelor flowsheet, PropertyParameterObject - aPropertyParameterBlock object.} property_package_args A ConfigBlock with arguments to be passed to a propertyblock(s) and used when constructing these, default -None. Valid values: { see property package fordocumentation.} reaction_package Reaction parameter object used to define reactioncalculations, default - None. Valid values: {None - no reaction package, ReactionParameterBlock- a ReactionParameterBlock object.} reaction_package_args A ConfigBlock with arguments to be passed to a reactionblock(s) and used when constructing these, default -None. Valid values: { see reaction package fordocumentation.} length_domain_set A list of values to be used when constructing the lengthdomain of the reactor. Point must lie between 0.0 and 1.0,default - [0.0, 1.0]. Valid values: { a list offloats} transformation_method Method to use to transform domain. Must be a methodrecognised by the Pyomo TransformationFactory, default- “dae.finite_difference”. transformation_scheme Scheme to use when transformating domain. See Pyomodocumentation for supported schemes, default -“BACKWARD”. finite_elements Number of finite elements to use when transforming lengthdomain, default - 20. collocation_points Number of collocation points to use when transforminglength domain, default - 3. initialize (dict) – ProcessBlockData config for individual elements. Keysare BlockData indexes and values are dictionaries described under the“default” argument above. idx_map (function) – Function to take the index of a BlockData element andreturn the index in the initialize dict from which to read arguments.This can be provided to overide the default behavior of matching theBlockData index exactly to the index in initialize.

Returns:

(PFR) New instance

PFRData Class¶

class idaes.unit_models.plug_flow_reactor.PFRData(component)[source]¶

Standard Plug Flow Reactor Unit Model Class

build()[source]¶

Begin building model (pre-DAE transformation).

Parameters:	None –
Returns:	None