Feed Block

Feed Blocks are used to represent sources of material in Flowsheets. Feed blocks do not calculate phase equilibrium of the feed stream, and the composition of the material in the outlet stream will be exactly as specified in the input. For applications where the users wishes the outlet stream to be in phase equilibrium, see the Feed_Flash unit model.

Degrees of Freedom

The degrees of freedom of Feed blocks depends on the property package being used and the number of state variables necessary to fully define the system. Users should refer to documentation on the property package they are using.

Model Structure

Feed Blocks consists of a single StateBlock (named properties), each with one Outlet Port (named outlet). Feed Blocks also contain References to the state variables defined within the StateBlock

Additional Constraints

Feed Blocks write no additional constraints to the model.

Variables

Feed blocks add no additional Variables.

Feed Class

class idaes.unit_models.feed.Feed(*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 = False. Feed blocks are always steady-state.
    has_holdup
    Feed blocks do not contain holdup, thus this must be False.
    property_package
    Property parameter object used to define property calculations, default - useDefault. Valid values: { useDefault - use default package from parent model or flowsheet, PhysicalParameterObject - a PhysicalParameterBlock object.}
    property_package_args
    A ConfigBlock with arguments to be passed to a property block(s) and used when constructing these, default - None. Valid values: { see property package for documentation.}
  • initialize (dict) – ProcessBlockData config for individual elements. Keys are BlockData indexes and values are dictionaries described under the “default” argument above.
  • idx_map (function) – Function to take the index of a BlockData element and return the index in the initialize dict from which to read arguments. This can be provided to overide the default behavior of matching the BlockData index exactly to the index in initialize.
Returns:

(Feed) New instance

FeedData Class

class idaes.unit_models.feed.FeedData(component)[source]

Standard Feed Block Class

build()[source]

Begin building model.

Parameters:None –
Returns:None
initialize(state_args={}, outlvl=0, solver='ipopt', optarg={'tol': 1e-06})[source]

This method calls the initialization method of the state block.

Keyword Arguments:
 
  • state_args – a dict of arguments to be passed to the property package(s) to provide an initial state for initialization (see documentation of the specific property package) (default = {}).
  • outlvl –

    sets output level of initialisation routine

    • 0 = no output (default)
    • 1 = return solver state for each step in routine
    • 2 = return solver state for each step in subroutines
    • 3 = include solver output infomation (tee=True)
  • optarg – solver options dictionary object (default={‘tol’: 1e-6})
  • solver – str indicating which solver to use during initialization (default = ‘ipopt’)
Returns:

None