.. index:: pair: watertap.core.zero_order_sido;build_sido
.. currentmodule:: watertap.core.zero_order_sido
The build_sido 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 two outlets.
from idaes.core import declare_process_block_class
from watertap.core import build_sido, ZeroOrderBaseData
@declare_process_block_class("NanofiltrationZO")
class NanofiltrationZOData(ZeroOrderBaseData):
CONFIG = ZeroOrderBaseData.CONFIG()
def build(self):
super().build()
self._tech_type = "nanofiltration"
build_sido(self)The build_sido method constructs a simple representation of unit operation with a single inlet (named inlet) and two outlets (named treated and byproduct). A StateBlock is constructed for the inlet and each outlet with a Port associated with each of these.
The build_sido 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_comp | time, component | Fraction of mass flow of each component that goes to byproduct stream. |
The build_sido method writes the following constraints which relate the inlet state to those in the treated and byproduct streams. First, a mass recovery equation for water is written 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.
Next, a mass balance for water is written to relate the flowrate in the byproduct stream to that in the inlet and treated streams.
flow_balance(t):
M_{inlet,t,H2O} = M_{treated,t,H2O} + M_{byproduct,t,H2O}
Removal constraints are then written for each solute to relate the solute concentration in the byproduct stream to that in the inlet stream.
solute_removal_equation(t, j):
f_{t, j} \times M_{inlet,t,j} = M_{byproduct,t,j}
A mass balance constraint is then written for each solute.
solute_treated_equation(t, j):
M_{inlet,t,j} = M_{treated,t,j} + M_{byproduct,t,j}