Supercritical CO2 Property Surrogate with OMLT Surrogate Object - flowsheet_optimization (Part 3)

###############################################################################
# The Institute for the Design of Advanced Energy Systems Integrated Platform
# Framework (IDAES IP) was produced under the DOE Institute for the
# Design of Advanced Energy Systems (IDAES).
#
# Copyright (c) 2018-2023 by the software owners: The Regents of the
# University of California, through Lawrence Berkeley National Laboratory,
# National Technology & Engineering Solutions of Sandia, LLC, Carnegie Mellon
# University, West Virginia University Research Corporation, et al.
# All rights reserved.  Please see the files COPYRIGHT.md and LICENSE.md
# for full copyright and license information.
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Supercritical CO2 Property Surrogate with OMLT Surrogate Object - flowsheet_optimization (Part 3)#

Maintainer: Javal Vyas

Author: Javal Vyas

Updated: 2024-01-24

With the surrogate model being embedded in the property package, it is ready to be used in the flowsheet. We start by creating the following flowsheet using the IDAES package.

from IPython.display import Image
from pathlib import Path


def datafile_path(name):
    return Path("..") / name


Image(datafile_path("CO2_flowsheet.png"))
../../../../_images/d8050a37171e8e1c8ef9b92bd7f8a6b2f52abfff04d2faffafe235388ba5adee.png

1. Importing libraries#

We will be using the unit models from the IDAES package along with components from pyomo.environ and pyomo.network.

from pyomo.environ import (
    ConcreteModel,
    Block,
    Var,
    Param,
    Constraint,
    SolverFactory,
    TransformationFactory,
    TerminationCondition,
    value,
    Expression,
    minimize,
    units,
)
from pyomo.network import Arc, SequentialDecomposition

# Import IDAES libraries
from idaes.core import FlowsheetBlock, UnitModelBlockData
from idaes.models.unit_models import (
    Mixer,
    MomentumMixingType,
    PressureChanger,
    Heater,
    Separator,
    HeatExchanger,
)
from idaes.models.unit_models.pressure_changer import ThermodynamicAssumption
from idaes.core.util.model_statistics import degrees_of_freedom
from idaes.core.util.initialization import propagate_state
from properties import SCO2ParameterBlock

import idaes.logger as idaeslog

_log = idaeslog.getModelLogger("my_model", level=idaeslog.DEBUG, tag="model")
WARNING: DEPRECATED: pyomo.core.expr.current is deprecated.  Please import
expression symbols from pyomo.core.expr  (deprecated in 6.6.2) (called from
<frozen importlib._bootstrap>:241)

2. Constructing the flowsheet#

To construct the flowsheet we need to define a ConcreteModel using pyomo and then add a FlowsheetBlock to the ConcreteModel. Here since we are focusing on the steady state process, we shall have the dynamic flag as False in the FlowsheetBlock. Next, we define the properties in the FlowsheetBlock that we imported from the properties.py file. Then start adding the unit models to the FlowsheetBlock with the suitable arguments, after which we connect them using Arcs as in the flowsheet above.

Once we have the connected flowsheet, we initialize individual unit models. Before initializing, we fix desired variables for the desired behavior of the unit model and then use propagate_state to pass on the state variables to next unit model in the flowsheet. After completely initializing the flowsheet, we convert the network to a mathematical form by using network.expand_arcs from the TransformationFactory and apply it on the flowsheet block. Then we call the solver and solve the flowsheet to calculate the total work in the process.

def main():
    # Setup solver and options
    solver = SolverFactory("ipopt")
    outlvl = 0
    tee = True

    # Set up concrete model
    m = ConcreteModel()

    # Create a flowsheet block
    m.fs = FlowsheetBlock(dynamic=False)

    # Create the properties param block
    m.fs.properties = SCO2ParameterBlock()

    # Add unit models to the flowsheet
    m.fs.boiler = Heater(
        dynamic=False, property_package=m.fs.properties, has_pressure_change=True
    )

    m.fs.turbine = PressureChanger(
        dynamic=False,
        property_package=m.fs.properties,
        compressor=False,
        thermodynamic_assumption=ThermodynamicAssumption.isentropic,
    )

    m.fs.HTR_pseudo_shell = Heater(
        dynamic=False, property_package=m.fs.properties, has_pressure_change=True
    )

    m.fs.HTR_pseudo_tube = Heater(
        dynamic=False, property_package=m.fs.properties, has_pressure_change=True
    )

    m.fs.LTR_pseudo_shell = Heater(
        dynamic=False, property_package=m.fs.properties, has_pressure_change=True
    )

    m.fs.LTR_pseudo_tube = Heater(
        dynamic=False, property_package=m.fs.properties, has_pressure_change=True
    )

    m.fs.splitter_1 = Separator(
        property_package=m.fs.properties, outlet_list=["bypass", "to_cooler"]
    )

    m.fs.co2_cooler = Heater(
        dynamic=False, property_package=m.fs.properties, has_pressure_change=True
    )

    m.fs.main_compressor = PressureChanger(
        dynamic=False,
        property_package=m.fs.properties,
        compressor=True,
        thermodynamic_assumption=ThermodynamicAssumption.isentropic,
    )

    m.fs.bypass_compressor = PressureChanger(
        dynamic=False,
        property_package=m.fs.properties,
        compressor=True,
        thermodynamic_assumption=ThermodynamicAssumption.isentropic,
    )

    m.fs.splitter_2 = Separator(
        property_package=m.fs.properties,
        ideal_separation=False,
        outlet_list=["to_FG_cooler", "to_LTR"],
    )

    m.fs.FG_cooler = Heater(
        dynamic=False, property_package=m.fs.properties, has_pressure_change=True
    )

    m.fs.mixer = Mixer(
        property_package=m.fs.properties, inlet_list=["FG_out", "LTR_out", "bypass"]
    )

    # # Connect the flowsheet
    m.fs.s01 = Arc(source=m.fs.boiler.outlet, destination=m.fs.turbine.inlet)
    m.fs.s02 = Arc(source=m.fs.turbine.outlet, destination=m.fs.HTR_pseudo_shell.inlet)
    m.fs.s03 = Arc(
        source=m.fs.HTR_pseudo_shell.outlet, destination=m.fs.LTR_pseudo_shell.inlet
    )
    m.fs.s04 = Arc(
        source=m.fs.LTR_pseudo_shell.outlet, destination=m.fs.splitter_1.inlet
    )
    m.fs.s05 = Arc(source=m.fs.splitter_1.to_cooler, destination=m.fs.co2_cooler.inlet)
    m.fs.s06 = Arc(
        source=m.fs.splitter_1.bypass, destination=m.fs.bypass_compressor.inlet
    )
    m.fs.s07 = Arc(
        source=m.fs.co2_cooler.outlet, destination=m.fs.main_compressor.inlet
    )
    m.fs.s08 = Arc(source=m.fs.bypass_compressor.outlet, destination=m.fs.mixer.bypass)
    m.fs.s09 = Arc(
        source=m.fs.main_compressor.outlet, destination=m.fs.splitter_2.inlet
    )
    m.fs.s10 = Arc(
        source=m.fs.splitter_2.to_FG_cooler, destination=m.fs.FG_cooler.inlet
    )
    m.fs.s11 = Arc(
        source=m.fs.splitter_2.to_LTR, destination=m.fs.LTR_pseudo_tube.inlet
    )
    m.fs.s12 = Arc(source=m.fs.LTR_pseudo_tube.outlet, destination=m.fs.mixer.LTR_out)
    m.fs.s13 = Arc(source=m.fs.FG_cooler.outlet, destination=m.fs.mixer.FG_out)
    m.fs.s14 = Arc(source=m.fs.mixer.outlet, destination=m.fs.HTR_pseudo_tube.inlet)

    # initialize twice if needed
    def init_once_or_twice(blk, outlvl=0):
        try:
            blk.initialize(outlvl=outlvl)
        except:
            blk.initialize(outlvl=outlvl)

    # NETL Baseline
    m.fs.boiler.inlet.flow_mol.fix(121.1)
    m.fs.boiler.inlet.temperature.fix(685.15)
    m.fs.boiler.inlet.pressure.fix(34.51)

    m.fs.boiler.outlet.temperature.fix(893.15)  # Turbine inlet T = 620 C
    m.fs.boiler.deltaP.fix(-0.21)

    init_once_or_twice(m.fs.boiler)

    propagate_state(m.fs.s01)

    m.fs.turbine.ratioP.fix(1 / 3.68)
    m.fs.turbine.efficiency_isentropic.fix(0.927)
    m.fs.turbine.initialize(outlvl=outlvl)

    propagate_state(m.fs.s02)
    m.fs.HTR_pseudo_shell.outlet.temperature.fix(489.15)
    m.fs.HTR_pseudo_shell.deltaP.fix(-0.07)

    init_once_or_twice(m.fs.HTR_pseudo_shell)

    propagate_state(m.fs.s03)

    m.fs.LTR_pseudo_shell.outlet.temperature.fix(354.15)
    m.fs.LTR_pseudo_shell.deltaP.fix(-0.07)
    m.fs.LTR_pseudo_shell.initialize(outlvl=outlvl)

    propagate_state(m.fs.s04)
    m.fs.splitter_1.split_fraction[0, "bypass"].fix(0.25)

    m.fs.splitter_1.initialize(outlvl=outlvl)

    propagate_state(m.fs.s05)
    m.fs.co2_cooler.outlet.temperature.fix(308.15)
    m.fs.co2_cooler.deltaP.fix(-0.07)
    m.fs.co2_cooler.initialize(outlvl=outlvl)

    propagate_state(m.fs.s06)
    m.fs.bypass_compressor.efficiency_isentropic.fix(0.85)
    m.fs.bypass_compressor.ratioP.fix(3.8)
    m.fs.bypass_compressor.initialize(outlvl=outlvl)

    propagate_state(m.fs.s07)
    m.fs.main_compressor.efficiency_isentropic.fix(0.85)
    m.fs.main_compressor.ratioP.fix(3.8)
    m.fs.main_compressor.initialize(outlvl=outlvl)

    propagate_state(m.fs.s09)

    m.fs.splitter_2.split_fraction[0, "to_FG_cooler"].fix(0.046)
    m.fs.splitter_2.initialize(outlvl=outlvl)

    propagate_state(m.fs.s10)
    m.fs.FG_cooler.outlet.temperature.fix(483.15)
    m.fs.FG_cooler.deltaP.fix(-0.06)
    m.fs.FG_cooler.initialize(outlvl=outlvl)

    propagate_state(m.fs.s11)

    m.fs.LTR_pseudo_tube.deltaP.fix(0)
    m.fs.LTR_pseudo_tube.heat_duty[0].fix(-value(m.fs.LTR_pseudo_shell.heat_duty[0]))
    m.fs.LTR_pseudo_tube.initialize(outlvl=outlvl)

    # Add constraint heats of the LTR_pseudo shell and tube
    m.fs.LTR_pseudo_tube.heat_duty[0].unfix()
    m.fs.c1 = Constraint(
        expr=m.fs.LTR_pseudo_shell.heat_duty[0] == -m.fs.LTR_pseudo_tube.heat_duty[0]
    )

    propagate_state(m.fs.s08)
    propagate_state(m.fs.s12)
    propagate_state(m.fs.s13)

    m.fs.mixer.initialize(outlvl=outlvl)

    propagate_state(m.fs.s14)

    m.fs.HTR_pseudo_tube.heat_duty[0].fix(-value(m.fs.HTR_pseudo_shell.heat_duty[0]))
    m.fs.HTR_pseudo_tube.deltaP.fix(-0.07)
    m.fs.HTR_pseudo_tube.initialize(outlvl=outlvl)

    m.fs.HTR_pseudo_tube.heat_duty[0].unfix()
    m.fs.c2 = Constraint(
        expr=m.fs.HTR_pseudo_shell.heat_duty[0] == -m.fs.HTR_pseudo_tube.heat_duty[0]
    )

    TransformationFactory("network.expand_arcs").apply_to(m.fs)

    print("--------------------------------------------------------------------")
    print("The degrees of freedom for the flowsheet is ", degrees_of_freedom(m))
    print("--------------------------------------------------------------------")

    solver.solve(m, tee=tee)

    #
    from idaes.core.util.units_of_measurement import (
        convert_quantity_to_reporting_units,
        report_quantity,
    )

    # Print reports
    for i in m.fs.component_objects(Block):
        if isinstance(i, UnitModelBlockData):
            i.report()

    # Converting units for readability
    print(
        -1 * value(units.convert(m.fs.turbine.work_mechanical[0], units.kW))
        - 1 * value(units.convert(m.fs.main_compressor.work_mechanical[0], units.kW))
        - 1 * value(units.convert(m.fs.bypass_compressor.work_mechanical[0], units.kW)),
        units.kW,
    )
    return m


if __name__ == "__main__":
    m = main()
2024-01-24 21:41:57 [INFO] idaes.init.fs.boiler.control_volume: Initialization Complete
2024-01-24 21:42:01 [INFO] idaes.init.fs.boiler: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:02 [INFO] idaes.init.fs.turbine: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:03 [INFO] idaes.init.fs.HTR_pseudo_shell.control_volume: Initialization Complete
2024-01-24 21:42:03 [INFO] idaes.init.fs.HTR_pseudo_shell: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:03 [INFO] idaes.init.fs.LTR_pseudo_shell.control_volume: Initialization Complete
2024-01-24 21:42:03 [INFO] idaes.init.fs.LTR_pseudo_shell: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:04 [INFO] idaes.init.fs.splitter_1: Initialization Step 2 Complete: optimal - Optimal Solution Found
2024-01-24 21:42:04 [INFO] idaes.init.fs.co2_cooler.control_volume: Initialization Complete
2024-01-24 21:42:04 [INFO] idaes.init.fs.co2_cooler: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:05 [INFO] idaes.init.fs.bypass_compressor: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:07 [INFO] idaes.init.fs.main_compressor: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:07 [INFO] idaes.init.fs.splitter_2: Initialization Step 2 Complete: optimal - Optimal Solution Found
2024-01-24 21:42:07 [INFO] idaes.init.fs.FG_cooler.control_volume: Initialization Complete
2024-01-24 21:42:08 [INFO] idaes.init.fs.FG_cooler: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:08 [INFO] idaes.init.fs.LTR_pseudo_tube.control_volume: Initialization Complete
2024-01-24 21:42:08 [INFO] idaes.init.fs.LTR_pseudo_tube: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:09 [INFO] idaes.init.fs.mixer: Initialization Complete: optimal - Optimal Solution Found
2024-01-24 21:42:09 [INFO] idaes.init.fs.HTR_pseudo_tube.control_volume: Initialization Complete
2024-01-24 21:42:09 [INFO] idaes.init.fs.HTR_pseudo_tube: Initialization Complete: optimal - Optimal Solution Found
--------------------------------------------------------------------
The degrees of freedom for the flowsheet is  0
--------------------------------------------------------------------
Ipopt 3.13.2: 

******************************************************************************
This program contains Ipopt, a library for large-scale nonlinear optimization.
 Ipopt is released as open source code under the Eclipse Public License (EPL).
         For more information visit http://projects.coin-or.org/Ipopt

This version of Ipopt was compiled from source code available at
    https://github.com/IDAES/Ipopt as part of the Institute for the Design of
    Advanced Energy Systems Process Systems Engineering Framework (IDAES PSE
    Framework) Copyright (c) 2018-2019. See https://github.com/IDAES/idaes-pse.

This version of Ipopt was compiled using HSL, a collection of Fortran codes
    for large-scale scientific computation.  All technical papers, sales and
    publicity material resulting from use of the HSL codes within IPOPT must
    contain the following acknowledgement:
        HSL, a collection of Fortran codes for large-scale scientific
        computation. See http://www.hsl.rl.ac.uk.
******************************************************************************

This is Ipopt version 3.13.2, running with linear solver ma27.

Number of nonzeros in equality constraint Jacobian...:    51411
Number of nonzeros in inequality constraint Jacobian.:        0
Number of nonzeros in Lagrangian Hessian.............:     2674

Total number of variables............................:     5920
                     variables with only lower bounds:       32
                variables with lower and upper bounds:     5669
                     variables with only upper bounds:        0
Total number of equality constraints.................:     5920
Total number of inequality constraints...............:        0
        inequality constraints with only lower bounds:        0
   inequality constraints with lower and upper bounds:        0
        inequality constraints with only upper bounds:        0

iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du alpha_pr  ls
   0  0.0000000e+00 9.10e-01 1.00e+00  -1.0 0.00e+00    -  0.00e+00 0.00e+00   0
   1  0.0000000e+00 7.86e-09 7.53e-01  -1.0 9.10e-01    -  9.89e-01 1.00e+00h  1

Number of Iterations....: 1

                                   (scaled)                 (unscaled)
Objective...............:   0.0000000000000000e+00    0.0000000000000000e+00
Dual infeasibility......:   0.0000000000000000e+00    0.0000000000000000e+00
Constraint violation....:   1.1641532182693481e-10    7.8580342233181000e-09
Complementarity.........:   0.0000000000000000e+00    0.0000000000000000e+00
Overall NLP error.......:   1.1641532182693481e-10    7.8580342233181000e-09


Number of objective function evaluations             = 2
Number of objective gradient evaluations             = 2
Number of equality constraint evaluations            = 2
Number of inequality constraint evaluations          = 0
Number of equality constraint Jacobian evaluations   = 2
Number of inequality constraint Jacobian evaluations = 0
Number of Lagrangian Hessian evaluations             = 1
Total CPU secs in IPOPT (w/o function evaluations)   =      0.362
Total CPU secs in NLP function evaluations           =      0.008

EXIT: Optimal Solution Found.

====================================================================================
Unit : fs.boiler                                                           Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key       : Value      : Units : Fixed : Bounds
    Heat Duty : 1.3854e+06 :  watt : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second 1.2110e+05 1.2110e+05
    temperature         kelvin     685.15     893.15
    pressure            pascal 3.4510e+07 3.4300e+07
====================================================================================

====================================================================================
Unit : fs.turbine                                                          Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key                   : Value       : Units         : Fixed : Bounds
    Isentropic Efficiency :     0.92700 : dimensionless :  True : (None, None)
          Mechanical Work : -1.0221e+06 :          watt : False : (None, None)
          Pressure Change :     -24.979 :        pascal : False : (None, None)
           Pressure Ratio :     0.27174 : dimensionless :  True : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second 1.2110e+05 1.2110e+05
    temperature         kelvin     893.15     719.28
    pressure            pascal 3.4300e+07 9.3207e+06
====================================================================================

====================================================================================
Unit : fs.HTR_pseudo_shell                                                 Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key       : Value       : Units : Fixed : Bounds
    Heat Duty : -1.5254e+06 :  watt : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second 1.2110e+05 1.2110e+05
    temperature         kelvin     719.28     489.15
    pressure            pascal 9.3207e+06 9.2507e+06
====================================================================================

====================================================================================
Unit : fs.HTR_pseudo_tube                                                  Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key       : Value      : Units : Fixed : Bounds
    Heat Duty : 1.5254e+06 :  watt : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second 1.2110e+05 1.2110e+05
    temperature         kelvin     543.23     750.68
    pressure            pascal 3.4560e+07 3.4490e+07
====================================================================================

====================================================================================
Unit : fs.LTR_pseudo_shell                                                 Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key       : Value       : Units : Fixed : Bounds
    Heat Duty : -1.0875e+06 :  watt : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second 1.2110e+05 1.2110e+05
    temperature         kelvin     489.15     354.15
    pressure            pascal 9.2507e+06 9.1807e+06
====================================================================================

====================================================================================
Unit : fs.LTR_pseudo_tube                                                  Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key       : Value      : Units : Fixed : Bounds
    Heat Duty : 1.0875e+06 :  watt : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second     86647.     86647.
    temperature         kelvin     396.40     579.39
    pressure            pascal 3.4620e+07 3.4620e+07
====================================================================================

====================================================================================
Unit : fs.splitter_1                                                       Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key                             : Value   : Units         : Fixed : Bounds
       Split Fraction [('bypass',)] : 0.25000 : dimensionless :  True : (None, None)
    Split Fraction [('to_cooler',)] : 0.75000 : dimensionless : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     bypass    to_cooler
    flow_mol     mole / second 1.2110e+05     30275.     90825.
    temperature         kelvin     354.15     354.15     354.15
    pressure            pascal 9.1807e+06 9.1807e+06 9.1807e+06
====================================================================================

====================================================================================
Unit : fs.co2_cooler                                                       Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key       : Value       : Units : Fixed : Bounds
    Heat Duty : -3.1174e+05 :  watt : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second     90825.     90825.
    temperature         kelvin     354.15     308.15
    pressure            pascal 9.1807e+06 9.1107e+06
====================================================================================

====================================================================================
Unit : fs.main_compressor                                                  Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key                   : Value      : Units         : Fixed : Bounds
    Isentropic Efficiency :    0.85000 : dimensionless :  True : (None, None)
          Mechanical Work : 2.7059e+05 :          watt : False : (None, None)
          Pressure Change :     25.510 :        pascal : False : (None, None)
           Pressure Ratio :     3.8000 : dimensionless :  True : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second     90825.     90825.
    temperature         kelvin     308.15     396.40
    pressure            pascal 9.1107e+06 3.4620e+07
====================================================================================

====================================================================================
Unit : fs.bypass_compressor                                                Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key                   : Value      : Units         : Fixed : Bounds
    Isentropic Efficiency :    0.85000 : dimensionless :  True : (None, None)
          Mechanical Work : 1.0998e+05 :          watt : False : (None, None)
          Pressure Change :     25.706 :        pascal : False : (None, None)
           Pressure Ratio :     3.8000 : dimensionless :  True : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second     30275.     30275.
    temperature         kelvin     354.15     452.96
    pressure            pascal 9.1807e+06 3.4886e+07
====================================================================================

====================================================================================
Unit : fs.splitter_2                                                       Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key                                : Value    : Units         : Fixed : Bounds
    Split Fraction [('to_FG_cooler',)] : 0.046000 : dimensionless :  True : (None, None)
          Split Fraction [('to_LTR',)] :  0.95400 : dimensionless : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet    to_FG_cooler   to_LTR  
    flow_mol     mole / second     90825.       4177.9      86647.
    temperature         kelvin     396.40       396.40      396.40
    pressure            pascal 3.4620e+07   3.4620e+07  3.4620e+07
====================================================================================

====================================================================================
Unit : fs.FG_cooler                                                        Time: 0.0
------------------------------------------------------------------------------------
    Unit Performance

    Variables: 

    Key       : Value  : Units : Fixed : Bounds
    Heat Duty : 25836. :  watt : False : (None, None)

------------------------------------------------------------------------------------
    Stream Table
                    Units         Inlet     Outlet  
    flow_mol     mole / second     4177.9     4177.9
    temperature         kelvin     396.40     483.15
    pressure            pascal 3.4620e+07 3.4560e+07
====================================================================================

====================================================================================
Unit : fs.mixer                                                            Time: 0.0
------------------------------------------------------------------------------------
    Stream Table
                    Units        FG_out     LTR_out    bypass     Outlet  
    flow_mol     mole / second     4177.9     86647.     30275. 1.2110e+05
    temperature         kelvin     483.15     579.39     452.96     543.23
    pressure            pascal 3.4560e+07 3.4620e+07 3.4886e+07 3.4560e+07
====================================================================================
641.5293430698576 kW