Inquiries about HXN errors

[zasddsgg]

Hello, when I execute HXN, the following error will be reported, which is caused by unit H102, which is heating N2 under high pressure (Nitrogen is used to provide an inert environment for the glucose reaction). May I ask how to solve this error? Is it because N2.Cn.l.method = N2.Cn.g.method = "COOLPROP" (https://biosteam.readthedocs.io/en/latest/tutorial/Convergence.html#Importance-of-thermodynamic-property-package:~:text=N2.Cn.l.method%20%3D%20N2.Cn.g.method%20%3D%20%22COOLPROP%22%20%23%20You%20may%20need%20to%20%22pip%20install%20coolprop%22%20for%20this%0AN2.reset_free_energies()%20%23%20This%20is%20necessary%20to%20update%20enthalpy%20and%20entropy%20algorithms%20with%20new%20heat%20capacities%0Asys.reset_cache()) is not added?
Some of the code for H102 is as follows.

import biosteam as bst
bst.nbtutorial()
bst.settings.set_thermo(['nitrogen'])
nitrogen = bst.Stream(
    ID='nitrogen',
    total_flow=100,
    units='kg/hr',
    N2=1,
    phase='g',
)
C101 = bst.units.IsothermalCompressor('C101', nitrogen, P=7000000)
H102 = bst.units.HXutility('H102', C101-0, T=200+273.15, rigorous=True)
HXN = bst.HeatExchangerNetwork('HXN', T_min_app = 10)
sys = bst.main_flowsheet.create_system('sys')
sys.simulate()

The error information is as follows.

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\_system.py:2631, in System.simulate(self, update_configuration, units, design_and_cost, **kwargs)
   2611 def simulate(self, update_configuration: Optional[bool]=None, units=None, 
   2612              design_and_cost=None, **kwargs):
   2613     """
   2614     If system is dynamic, run the system dynamically. Otherwise, converge 
   2615     the path of unit operations to steady state. After running/converging 
   (...)
   2629         
   2630     """
-> 2631     with self.flowsheet.temporary():
   2632         specifications = self._specifications
   2633         if specifications and not self._running_specifications:

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\_flowsheet.py:38, in TemporaryFlowsheet.__exit__(self, type, exception, traceback)
     36 def __exit__(self, type, exception, traceback):
     37     main_flowsheet.set_flowsheet(self.original)
---> 38     if exception: raise exception

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\_system.py:2687, in System.simulate(self, update_configuration, units, design_and_cost, **kwargs)
   2681         outputs = self.simulate(
   2682             update_configuration=True, 
   2683             design_and_cost=design_and_cost,
   2684             **kwargs
   2685         )
   2686     else:
-> 2687         raise error
   2688 else:
   2689     if (not update_configuration # Avoid infinite loop
   2690         and self._connections != [i.get_connection() for i in self.streams]):
   2691         # Connections has been updated within simulation.

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\_system.py:2675, in System.simulate(self, update_configuration, units, design_and_cost, **kwargs)
   2673 try:
   2674     outputs = self.converge(**kwargs)
-> 2675     if design_and_cost: self._summary()
   2676 except Exception as error:
   2677     if update_configuration: raise error # Avoid infinite loop

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\_system.py:2390, in System._summary(self)
   2388     f(i, i._summary)
   2389 for i in self._facilities:
-> 2390     if isa(i, Unit): f(i, i.simulate)
   2391     elif isa(i, System):
   2392         f(i, i.converge)

File D:\anaconda\envs\zddd\lib\site-packages\thermosteam\exceptions.py:94, in try_method_with_object_stamp(object, method, args)
     92     raise StampedKeyError(message_with_object_stamp(object, repr(error.args[0])))
     93 except Exception as error:
---> 94     raise_error_with_object_stamp(object, error)

File D:\anaconda\envs\zddd\lib\site-packages\thermosteam\exceptions.py:84, in raise_error_with_object_stamp(object, error)
     82     error.args = (message_with_object_stamp(object, msg), *args)
     83 except: pass
---> 84 raise error

File D:\anaconda\envs\zddd\lib\site-packages\thermosteam\exceptions.py:88, in try_method_with_object_stamp(object, method, args)
     86 def try_method_with_object_stamp(object, method, args=()):
     87     try:
---> 88         return method(*args)
     89     except StampedKeyError as error:
     90         raise StampedKeyError(message_with_object_stamp(object, error.args[0]))

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\_unit.py:1097, in Unit.simulate(self, run, design_kwargs, cost_kwargs)
   1095     self._load_stream_links()
   1096     self.run()
-> 1097 self._summary(design_kwargs, cost_kwargs)

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\_unit.py:975, in Unit._summary(self, design_kwargs, cost_kwargs, lca_kwargs)
    973 if not self._skip_simulation_when_inlets_are_empty or not all([i.isempty() for i in self._ins]): 
    974     self._design(**design_kwargs) if design_kwargs else self._design()
--> 975     self._cost(**cost_kwargs) if cost_kwargs else self._cost()
    976     self._lca(**lca_kwargs) if lca_kwargs else self._lca()
    977     self._check_utilities()

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\facilities\hxn\_heat_exchanger_network.py:155, in HeatExchangerNetwork._cost(self)
    150     hxs = [hu.unit for hu in hx_utils]
    151     use_cached_network = (
    152         sorted(hxs, key=lambda x: x.ID) 
    153         == sorted(self.original_heat_exchangers, key=lambda x: x.ID)
    154     )
--> 155 with flowsheet.temporary(), bst.IgnoreDockingWarnings():
    156     if use_cached_network:
    157         hx_heat_utils_rearranged = [i.heat_utilities[0] for i in hxs]

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\_flowsheet.py:38, in TemporaryFlowsheet.__exit__(self, type, exception, traceback)
     36 def __exit__(self, type, exception, traceback):
     37     main_flowsheet.set_flowsheet(self.original)
---> 38     if exception: raise exception

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\facilities\hxn\_heat_exchanger_network.py:155, in HeatExchangerNetwork._cost(self)
    150     hxs = [hu.unit for hu in hx_utils]
    151     use_cached_network = (
    152         sorted(hxs, key=lambda x: x.ID) 
    153         == sorted(self.original_heat_exchangers, key=lambda x: x.ID)
    154     )
--> 155 with flowsheet.temporary(), bst.IgnoreDockingWarnings():
    156     if use_cached_network:
    157         hx_heat_utils_rearranged = [i.heat_utilities[0] for i in hxs]

File D:\anaconda\envs\zddd\lib\site-packages\thermosteam\network.py:270, in IgnoreDockingWarnings.__exit__(self, type, exception, traceback)
    268 global DOCKING_WARNINGS
    269 DOCKING_WARNINGS = self.original_value
--> 270 if exception: raise exception

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\facilities\hxn\_heat_exchanger_network.py:191, in HeatExchangerNetwork._cost(self)
    186 self.HXN_flowsheet = HXN_F = bst.main_flowsheet
    187 for i in HXN_F.registries: i.clear()
    188 HXs_hot_side, HXs_cold_side, new_HX_utils, hxs, T_in_arr,\
    189 T_out_arr, pinch_T_arr, C_flow_vector, hx_heat_utils_rearranged, streams_inlet, stream_HXs_dict,\
    190 hot_indices, cold_indices = \
--> 191 synthesize_network(hx_utils, self.T_min_app, self.Qmin, 
    192                    self.force_ideal_thermo, self.avoid_recycle)
    193 new_HXs = HXs_hot_side + HXs_cold_side
    194 self.cold_indices = cold_indices

File D:\anaconda\envs\zddd\lib\site-packages\biosteam\facilities\hxn\hxn_synthesis.py:541, in synthesize_network(hus, T_min_app, Qmin, force_ideal_thermo, avoid_recycle)
    539 new_HX_util._run()
    540 s_out = new_HX_util.outs[0]
--> 541 np.testing.assert_allclose(s_out.H, H_out_arr[cold], rtol=1e-2, atol=1.)
    542 atol_T = 5. if 's' in hxs[cold].outs[0].phases else 0.001
    543 np.testing.assert_allclose(s_out.T, T_out_arr[cold], rtol=5e-2, atol=atol_T)

    [... skipping hidden 1 frame]

File D:\anaconda\envs\zddd\lib\contextlib.py:79, in ContextDecorator.__call__.<locals>.inner(*args, **kwds)
     76 @wraps(func)
     77 def inner(*args, **kwds):
     78     with self._recreate_cm():
---> 79         return func(*args, **kwds)

File D:\anaconda\envs\zddd\lib\site-packages\numpy\testing\_private\utils.py:797, in assert_array_compare(comparison, x, y, err_msg, verbose, header, precision, equal_nan, equal_inf, strict)
    793         err_msg += '\n' + '\n'.join(remarks)
    794         msg = build_err_msg([ox, oy], err_msg,
    795                             verbose=verbose, header=header,
    796                             names=('x', 'y'), precision=precision)
--> 797         raise AssertionError(msg)
    798 except ValueError:
    799     import traceback

AssertionError: <HeatExchangerNetwork: HXN> 
Not equal to tolerance rtol=0.01, atol=1

Mismatched elements: 1 / 1 (100%)
Max absolute difference: 584904.311
Max relative difference: 0.178
 x: array(2693095.764976)
 y: array(3278000.076034)