#################################################################################
# WaterTAP Copyright (c) 2020-2024, The Regents of the University of California,
# through Lawrence Berkeley National Laboratory, Oak Ridge National Laboratory,
# National Renewable Energy Laboratory, and National Energy Technology
# Laboratory (subject to receipt of any required approvals from the U.S. Dept.
# of Energy). All rights reserved.
#
# Please see the files COPYRIGHT.md and LICENSE.md for full copyright and license
# information, respectively. These files are also available online at the URL
# "https://github.com/watertap-org/watertap/"
#################################################################################
"""
This module contains a zero-order representation of a sedimentation unit
operation.
"""
import pyomo.environ as pyo
from pyomo.environ import Constraint, units as pyunits, Var
from idaes.core import declare_process_block_class
from watertap.core import build_sido, constant_intensity, ZeroOrderBaseData
# Some more information about this module
__author__ = "Adam Atia"
[docs]@declare_process_block_class("SedimentationZO")
class SedimentationZOData(ZeroOrderBaseData):
"""
Zero-Order model for a Sedimentation unit operation.
"""
CONFIG = ZeroOrderBaseData.CONFIG()
[docs] def build(self):
super().build()
self._tech_type = "sedimentation"
build_sido(self)
constant_intensity(self)
# TODO: Does it really make sense for this to be indexed by time?
self.basin_surface_area = Var(
self.flowsheet().config.time,
units=pyunits.ft**2,
doc="Surface area of sedimentation tank",
)
self.settling_velocity = Var(
self.flowsheet().config.time,
units=pyunits.m / pyunits.s,
doc="Particle settling velocity",
)
self._fixed_perf_vars.append(self.settling_velocity)
self._perf_var_dict["Basin Surface Area (ft^2)"] = self.basin_surface_area
self._perf_var_dict["Settling Velocity (m/s)"] = self.settling_velocity
def rule_basin_surface_area(b, t):
return b.basin_surface_area[t] == pyunits.convert(
b.properties_in[t].flow_vol / b.settling_velocity[t],
to_units=pyunits.ft**2,
)
self.basin_surface_area_constraint = Constraint(
self.flowsheet().time, rule=rule_basin_surface_area
)
if self.config.process_subtype == "phosphorus_capture":
self.phosphorus_solids_ratio = Var(
self.flowsheet().config.time,
units=pyunits.dimensionless,
doc="Mass fraction of phosphorus in settleable solids",
)
self._fixed_perf_vars.append(self.phosphorus_solids_ratio)
self._perf_var_dict["Phosphorus-Solids Ratio (kg/kg)"] = (
self.phosphorus_solids_ratio
)
# This subtype is intended to be used explicitly for phosphorous capture.
# If the user provides TSS, the amount of settled phosphate would be determined based on
# an assumed fraction of phosphate in TSS. Alternatively, the user could provide phosphates
# as the species, and the amount of solids + phosphate settled would be reported.
# However, the user cannot provide both TSS and phosphates.
if (
"phosphates" in self.config.property_package.solute_set
and "tss" in self.config.property_package.solute_set
):
raise KeyError(
"tss and phosphates cannot both be defined in the solute_list. "
"Please choose one."
)
elif "phosphates" in self.config.property_package.solute_set:
self.final_solids_mass = Var(
self.flowsheet().config.time,
units=pyunits.kg / pyunits.s,
doc="Solids mass flow in byproduct stream",
)
@self.Constraint(
self.flowsheet().time,
doc="Solids mass flow in byproduct stream constraint",
)
def solids_mass_flow_constraint(b, t):
return (
b.final_solids_mass[t]
== b.properties_byproduct[t].flow_mass_comp["phosphates"]
/ b.phosphorus_solids_ratio[t]
)
self._perf_var_dict["Final mass flow of settled solids (kg/s)"] = (
self.final_solids_mass
)
elif "tss" in self.config.property_package.solute_set:
self.final_phosphate_mass = Var(
self.flowsheet().config.time,
units=pyunits.kg / pyunits.s,
doc="Phosphate mass flow in byproduct stream",
)
@self.Constraint(
self.flowsheet().time,
doc="Phosphate mass flow in byproduct stream constraint",
)
def phosphate_mass_flow_constraint(b, t):
return (
b.final_phosphate_mass[t]
== b.properties_byproduct[t].flow_mass_comp["tss"]
* b.phosphorus_solids_ratio[t]
)
self._perf_var_dict["Final mass flow of settled phosphate (kg/s)"] = (
self.final_phosphate_mass
)
else:
# Raise this error in case the user is intended to make use of the subtype but entered
# the wrong component names.
raise KeyError(
"One of the following should be specified in the solute_list: "
"tss or phosphates"
)
@property
def default_costing_method(self):
return self.cost_sedimentation
[docs] @staticmethod
def cost_sedimentation(blk, number_of_parallel_units=1):
"""
General method for costing sedimentaion processes. Capital cost is
based on the surface area of the basin.
Args:
number_of_parallel_units (int, optional) - cost this unit as
number_of_parallel_units parallel units (default: 1)
"""
t0 = blk.flowsheet().time.first()
if blk.unit_model.config.process_subtype != "phosphorus_capture":
sizing_term = blk.unit_model.basin_surface_area[t0] / pyo.units.foot**2
# Get parameter dict from database
parameter_dict = (
blk.unit_model.config.database.get_unit_operation_parameters(
blk.unit_model._tech_type,
subtype=blk.unit_model.config.process_subtype,
)
)
A, B = blk.unit_model._get_tech_parameters(
blk,
parameter_dict,
blk.unit_model.config.process_subtype,
["capital_a_parameter", "capital_b_parameter"],
)
# Determine if a costing factor is required
factor = parameter_dict["capital_cost"]["cost_factor"]
# Call general power law costing method
blk.unit_model._general_power_law_form(
blk, A, B, sizing_term, factor, number_of_parallel_units
)
else:
# Get parameter dict from database
parameter_dict = (
blk.unit_model.config.database.get_unit_operation_parameters(
blk.unit_model._tech_type,
subtype=blk.unit_model.config.process_subtype,
)
)
# Get costing parameter sub-block for this technology
unit_capex, unit_opex = blk.unit_model._get_tech_parameters(
blk,
parameter_dict,
blk.unit_model.config.process_subtype,
["unit_capex", "unit_opex"],
)
# Add cost variable and constraint
blk.capital_cost = pyo.Var(
initialize=1,
units=blk.config.flowsheet_costing_block.base_currency,
bounds=(0, None),
doc="Capital cost of unit operation",
)
capex_expr = pyo.units.convert(
blk.unit_model.properties_in[t0].flow_vol * unit_capex,
to_units=blk.config.flowsheet_costing_block.base_currency,
)
# Determine if a costing factor is required
blk.costing_package.add_cost_factor(
blk, parameter_dict["capital_cost"]["cost_factor"]
)
blk.capital_cost_constraint = pyo.Constraint(
expr=blk.capital_cost == blk.cost_factor * capex_expr
)
# Add fixed operating cost variable and constraint
blk.fixed_operating_cost = pyo.Var(
initialize=1,
units=blk.config.flowsheet_costing_block.base_currency
/ blk.config.flowsheet_costing_block.base_period,
bounds=(0, None),
doc="Fixed operating cost of unit",
)
blk.fixed_operating_cost_constraint = pyo.Constraint(
expr=blk.fixed_operating_cost
== pyo.units.convert(
blk.unit_model.properties_in[t0].flow_vol * unit_opex,
to_units=blk.config.flowsheet_costing_block.base_currency
/ blk.config.flowsheet_costing_block.base_period,
)
)
# Register flows
blk.config.flowsheet_costing_block.cost_flow(
blk.unit_model.electricity[t0], "electricity"
)