Settings modules
This modul contains some of the required functions for the settings.
EIS_parameters(f_EIS)
This function gives the time parameters for the EIS_current density function.
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Source code in modules/settings_modules.py
def EIS_parameters(f_EIS):
"""This function gives the time parameters for the EIS_current density function.
Parameters
----------
f_EIS : tuple
EIS parameters. It is a tuple containing the power of the initial frequency 'f_power_min_EIS':
f_min_EIS = 10**f_power_min_EIS, the power of the final frequency 'f_power_max_EIS', the number of frequencies
tested 'nb_f_EIS' and the number of points calculated per specific period 'nb_points_EIS'.
Returns
-------
t_EIS : tuple
EIS parameters. It is a tuple containing the initial EIS time after stack equilibrium 't0_EIS', a list of time
parameters which gives the beginning of each frequency change 't_new_start_EIS', the final time 'tf_EIS', a list
of time parameters which gives the estimated time for reaching equilibrium at each frequency
'delta_t_break_EIS', and a list of time parameters which gives the estimated time for measuring the voltage
response at each frequency 'delta_t_measurement_EIS'.
"""
# Initialisation
# Frequencies
f_power_min_EIS, f_power_max_EIS, nb_f_EIS, nb_points_EIS = f_EIS # They are the frequency parameters for the EIS
# simulation.
f = np.logspace(f_power_min_EIS, f_power_max_EIS, num=nb_f_EIS) # It is the tested frequencies
nb_period_break_EIS, nb_period_measurement_EIS = 50, 50 # They are the number of temporal periods which are used
# for break and for measurement. It is more accurate to use
# periods than time as the frequency range is big.
# Time parameters
delta_t_break_EIS = np.array([]) # It is the estimated time for reaching equilibrium at each frequency.
delta_t_measurement_EIS = np.array([]) # It is the estimated time for measuring the voltage response.
# Time parameters calculation
t0_EIS = 1 / f[0] # s. It is the simulation starting time.
# [0, t0_EIS] is used to let the stack equilibrate to i_EIS.
t_new_start_EIS = np.array([t0_EIS]) # It is a list of time parameters which gives the beginning of each frequency
# change.
for i in range(nb_f_EIS): # The goal is to measure nb_f_EIS periods of the signal in order to have precise enough values.
T_i = 1 / (f[i]) # s. It is the period of the signal.
if i < (nb_f_EIS - 1):
delta_t_break_EIS = np.concatenate((delta_t_break_EIS, [nb_period_break_EIS * T_i]))
delta_t_measurement_EIS = np.concatenate((delta_t_measurement_EIS, [nb_period_measurement_EIS * T_i]))
next_start_EIS = t_new_start_EIS[i] + delta_t_break_EIS[i] + delta_t_measurement_EIS[i]
t_new_start_EIS = np.concatenate((t_new_start_EIS, [next_start_EIS]))
else:
delta_t_break_EIS = np.concatenate((delta_t_break_EIS, [nb_period_break_EIS * T_i]))
delta_t_measurement_EIS = np.concatenate((delta_t_measurement_EIS, [nb_period_measurement_EIS * T_i]))
tf_EIS = t_new_start_EIS[-1] + delta_t_break_EIS[-1] + delta_t_measurement_EIS[-1] # s. It is the
# simulation ending time
t_EIS = t0_EIS, t_new_start_EIS, tf_EIS, delta_t_break_EIS, delta_t_measurement_EIS
return t_EIS
stored_operating_inputs(type_fuel_cell)
This function gives the operating inputs which correspond to the given type_fuel_cell.
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Source code in modules/settings_modules.py
def stored_operating_inputs(type_fuel_cell):
"""This function gives the operating inputs which correspond to the given type_fuel_cell.
Parameters
----------
type_fuel_cell : str
Type of fuel cell configuration.
Returns
-------
Tfc : float
Desired fuel cell temperature in Kelvin.
Pa_des : float
Desired anode pressure in Pascal.
Pc_des : float
Desired cathode pressure in Pascal.
Sa : float
Stoichiometric ratio of hydrogen.
Sc : float
Stoichiometric ratio of oxygen.
Phi_a_des : float
Desired anode relative humidity.
Phi_c_des : float
Desired cathode relative humidity.
i_max_pola : float
Maximum current density for the polarization curve.
"""
# For EH-31 fuel cell
if type_fuel_cell == "EH-31_1.5":
Tfc = 74 + 273.15 # K. It is the desired fuel cell temperature.
Pa_des, Pc_des = 1.5e5, 1.5e5 # Pa. It is the desired pressure of the fuel gas (at the anode/cathode).
Sa, Sc = 1.2, 2.0 # It is the stoichiometric ratio (of hydrogen and oxygen).
Phi_a_des, Phi_c_des = 0.4, 0.6 # It is the desired relative humidity.
i_max_pola = 3.0e4 # A.m-2. It is the maximum current density for the polarization curve.
elif type_fuel_cell == "EH-31_2.0":
Tfc = 74 + 273.15 # K. It is the desired fuel cell temperature.
Pa_des, Pc_des = 2.0e5, 2.0e5 # Pa. It is the desired pressure of the fuel gas (at the anode/cathode).
Sa, Sc = 1.2, 2.0 # It is the stoichiometric ratio (of hydrogen and oxygen).
Phi_a_des, Phi_c_des = 0.4, 0.6 # It is the desired relative humidity.
i_max_pola = 3.0e4 # A.m-2. It is the maximum current density for the polarization curve.
elif type_fuel_cell == "EH-31_2.25":
Tfc = 74 + 273.15 # K. It is the desired fuel cell temperature.
Pa_des, Pc_des = 2.25e5, 2.25e5 # Pa. It is the desired pressure of the fuel gas (at the anode/cathode).
Sa, Sc = 1.2, 2.0 # It is the stoichiometric ratio (of hydrogen and oxygen).
Phi_a_des, Phi_c_des = 0.4, 0.6 # It is the desired relative humidity.
i_max_pola = 3.0e4 # A.m-2. It is the maximum current density for the polarization curve.
elif type_fuel_cell == "EH-31_2.5":
Tfc = 74 + 273.15 # K. It is the desired fuel cell temperature.
Pa_des, Pc_des = 2.5e5, 2.5e5 # Pa. It is the desired pressures of the fuel gas.
Sa, Sc = 1.2, 2.0 # It is the stoichiometric ratio (of hydrogen and oxygen).
Phi_a_des, Phi_c_des = 0.4, 0.6 # It is the desired relative humidity.
i_max_pola = 3.0e4 # A.m-2. It is the maximum current density for the polarization curve.
# For LF fuel cell
elif type_fuel_cell == "LF":
Tfc = 80 + 273.15 # K. It is the desired fuel cell temperature.
Pa_des, Pc_des = 101325, 101325 # Pa. It is the desired pressures of the fuel gas.
Sa, Sc = 2.0, 1.5 # It is the stoichiometric ratio (of hydrogen and oxygen).
Phi_a_des, Phi_c_des = 0.84, 0.59 # It is the desired relative humidity.
i_max_pola = 1.6e4 # A.m-2. It is the maximum current density for the polarization curve.
# For other fuel cells
else:
raise ValueError('the type_fuel_cell given is not valid.')
return Tfc, Pa_des, Pc_des, Sa, Sc, Phi_a_des, Phi_c_des, i_max_pola
stored_physical_parameters(type_fuel_cell)
This function gives the physical parameters which correspond to the given type_fuel_cell.
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Source code in modules/settings_modules.py
def stored_physical_parameters(type_fuel_cell):
"""This function gives the physical parameters which correspond to the given type_fuel_cell.
Parameters
----------
type_fuel_cell : str
Type of fuel cell configuration.
Returns
-------
Hcl : float
Thickness of the catalyst layer in m.
epsilon_mc : float
Volume fraction of ionomer in the CL.
tau : float
Pore structure coefficient.
Hmem : float
Thickness of the membrane in m.
Hgdl : float
Thickness of the gas diffusion layer in m.
epsilon_gdl : float
Anode/cathode GDL porosity.
epsilon_c : float
Compression ratio of the GDL.
Hgc : float
Thickness of the gas channel in m.
Wgc : float
Width of the gas channel in m.
Lgc : float
Length of the gas channel in m.
Aact : float
Active area of the cell in m².
e : float
Capillary exponent.
Re : float
Electron conduction resistance of the circuit in ohm.m².
i0_c_ref : float
Reference exchange current density at the cathode in A.m-2.
kappa_co : float
Crossover correction coefficient in mol.m-1.s-1.Pa-1.
kappa_c : float
Overpotential correction exponent.
a_slim : float
One of the limit liquid saturation coefficients: the slop of slim function.
b_slim : float
One of the limit liquid saturation coefficients: the intercept of slim function.
a_switch : float
One of the limit liquid saturation coefficients: the slop of s_switch function.
C_dl : float
Volumetric double layer capacitance in F.m-3.
"""
# For EH-31 fuel cell
if type_fuel_cell == "EH-31_1.5" or type_fuel_cell == "EH-31_2.0" or type_fuel_cell == "EH-31_2.25" or \
type_fuel_cell == "EH-31_2.5":
# Catalyst layer
Aact = 8.5e-3 # m². It is the active area of the catalyst layer.
Hcl = 1e-5 # m. It is the thickness of the anode or cathode catalyst layer.
epsilon_mc = 0.399 # It is the volume fraction of ionomer in the CL.
tau = 1.016 # It is the pore structure coefficient, without units.
# Membrane
Hmem = 2e-5 # m. It is the thickness of the membrane.
# Gas diffusion layer
Hgdl = 2e-4 # m. It is the thickness of the gas diffusion layer.
epsilon_gdl = 0.701 # It is the anode/cathode GDL porosity.
epsilon_c = 0.271 # It is the compression ratio of the GDL.
# Gas channel
Hgc = 5e-4 # m. It is the thickness of the gas channel.
Wgc = 4.5e-4 # m. It is the width of the gas channel.
Lgc = 9.67 # m. It is the length of the gas channel.
# Interaction parameters between water and PEMFC structure
e = 5.0 # It is the capillary exponent
# Voltage polarization
Re = 5.70e-07 # ohm.m². It is the electron conduction resistance of the circuit.
i0_c_ref = 2.79 # A.m-2.It is the reference exchange current density at the cathode.
kappa_co = 27.2 # mol.m-1.s-1.Pa-1. It is the crossover correction coefficient.
kappa_c = 1.61 # It is the overpotential correction exponent.
a_slim, b_slim, a_switch = 0.05553, 0.10514, 0.63654 # It is the limit liquid saturation coefficients.
C_scl = 2e7 # F.m-3. It is the volumetric space-charge layer capacitance.
# For LF fuel cell
elif type_fuel_cell == "LF":
# Catalyst layer
Hcl = 1e-5 # m. It is the thickness of the anode or cathode catalyst layer.
epsilon_mc = 0.27 # It is the volume fraction of ionomer in the CL.
tau = 1.2 # It is the pore structure coefficient, without units.
# Membrane
Hmem = 5.08e-5 # m. It is the thickness of the membrane.
# Gas diffusion layer
Hgdl = 4.2e-4 # m. It is the thickness of the gas diffusion layer.
epsilon_gdl = 0.6 # It is the anode/cathode GDL porosity.
epsilon_c = 0.21 # It is the compression ratio of the GDL.
# Gas channel.
Hgc = 1e-3 # m. It is the thickness of the gas channel.
Wgc = 8e-4 # m. It is the width of the gas channel.
Wrib = 7e-4 # m. It is the rib of the gas channel.
L1gc = 0.1 # m. It is the length of 1 channel.
Ngc = 16 # . It is the number of channels in the gas channel. It is taken to have Aact = 25cm².
Lgc = (L1gc + Wrib) * Ngc # m. It is the length of the gas channel.
Aact = (L1gc + 2 * Wrib) * (Wgc + Wrib) * Ngc + (L1gc + 2 * Wrib) * 7e-4 # m². It is the CL active area.
# Interaction parameters between water and PEMFC structure
e = 3.0 # It is the capillary exponent
# Voltage polarization
Re = 1e-6 # ohm.m². It is the electron conduction resistance of the circuit.
i0_c_ref = 10 # A.m-2.It is the reference exchange current density at the cathode.
kappa_co = 25 # mol.m-1.s-1.Pa-1. It is the crossover correction coefficient.
kappa_c = 1.5 # It is the overpotential correction exponent.
a_slim, b_slim, a_switch = 0, 1, 1 # It is the limit liquid saturation coefficients.
C_scl = 2e7 # F.m-3. It is the volumetric space-charge layer capacitance.
# For other fuel cells
else:
raise ValueError('the type_input given is not valid.')
return Hcl, epsilon_mc, tau, Hmem, Hgdl, epsilon_gdl, epsilon_c, \
Hgc, Wgc, Lgc, Aact, e, Re, i0_c_ref, kappa_co, kappa_c, a_slim, b_slim, a_switch, C_scl