Single Inlet - Single Outlet Helper Methods

The build_siso method is intended to be used to rapidly construct a standard set of material balance equations for zero-order type models with a single inlet and single outlet.

Usage

from idaes.core import declare_process_block_class
from watertap.core import build_siso, ZeroOrderBaseData

@declare_process_block_class("UVZO")
class UVZOData(ZeroOrderBaseData):

    CONFIG = ZeroOrderBaseData.CONFIG()

    def build(self):
        super().build()

        self._tech_type = "uv"

        build_siso(self)

Model Structure

The build_siso method constructs a simple representation of unit operation with one inlet (named inlet) and one outlet (named treated). A StateBlock is constructed for each inlet and outlet with an associated Port.

Variables

The build_siso method creates the following variables in addition to those created by the StateBlocks.

Variable	Name	Indices	Notes
\(r_{t}\)	recovery_frac_mass_H2O	time	Fraction of mass flow of water in inlet that goes to treated stream.
\(f_{t,j}\)	removal_frac_mass_solute	time, solutes	Fraction of mass flow of each solute that is removed from the inlet stream.

recovery_frac_mass_H2O is intended to be fixed to 1 (e.g., UV reactor which yields product stream without water losses), but the user can optionally set this to some fraction.

Constraints

The build_siso method writes the following constraints which relate the inlet state to the treated stream. First, a water recovery equation is written for water to relate the flowrate at the treated outlet to that at the inlet:

water_recovery_equation(t):

\[r_t \times M_{inlet,t,H2O} = M_{treated,t,H2O}\]

where \(M_{t,H2O}\) is mass flowrate of water at time \(t\).

Note, a mass balance for water is ignored since build_siso is intended to only account for constituent removal/conversion at the treated outlet. Thus, a mass balance constraint is only written for each solute.

solute_treated_equation(t, j):

\[(1 - f_{t, j}) \times M_{inlet,t,j} = M_{treated,t,j}\]

Module Documentation

Helper method for constructing material balances for zero-order type models with SISO behavior.

Two StateBlocks are added with two corresponding Ports:

properties_in –> inlet
properties_treated —> treated

Two additional variables are added:

recovery_frac_mass_H2O (indexed by time)
removal_frac_mass_solute (indexed by time and solute)

Two additional constraints are added to represent the material balances

water_recovery_equation (indexed by time)
solute_treated_equation (indexed by time and solute)

This method also sets private attributes on the unit model with references to the appropriate initialization and scaling methods to use and to return the inlet volumetric flow rate.