def setup_reaction_parameters(self):
r"""Setup parameters for reaction (gas name aliases and LHV)."""
self.fuel_list = []
fuels = [
'methane', 'ethane', 'propane', 'butane', 'hydrogen', 'nDodecane'
]
for f in fuels:
self.fuel_list += [
x for x in self.nw_fluids
if x in [a.replace(' ', '') for a in CP.get_aliases(f)]
]
if len(self.fuel_list) == 0:
msg = ('Your network\'s fluids do not contain any fuels, that are '
'available for the component ' + self.label + ' of type ' +
self.component() + '. Available fuels are: ' +
', '.join(fuels) + '.')
logging.error(msg)
raise TESPyComponentError(msg)
else:
msg = ('The fuels for component ' + self.label + ' of type ' +
self.component() + ' are: ' + ', '.join(self.fuel_list) +
'.')
logging.debug(msg)
for fluid in ['o2', 'co2', 'h2o', 'n2']:
try:
setattr(self, fluid, [
x for x in self.nw_fluids if x in [
a.replace(' ', '')
for a in CP.get_aliases(fluid.upper())
]
][0])
except IndexError:
msg = ('The component ' + self.label + ' (class ' +
self.__class__.__name__ + ') requires that the fluid '
'[fluid] is in the network\'s list of fluids.')
aliases = ', '.join(CP.get_aliases(fluid.upper()))
msg = msg.replace(
'[fluid]',
fluid.upper() + ' (aliases: ' + aliases + ')')
logging.error(msg)
raise TESPyComponentError(msg)
self.fuels = {}
for f in self.fuel_list:
self.fuels[f] = {}
structure = fluid_structure(f)
for el in ['C', 'H', 'O']:
if el in structure:
self.fuels[f][el] = structure[el]
else:
self.fuels[f][el] = 0
self.fuels[f]['LHV'] = self.calc_lhv(f)
def calc_lhv(self):
r"""
Calculate the lower heating value of the combustion chambers fuel.
Returns
-------
val : float
Lower heating value of the combustion chambers fuel.
.. math::
LHV = \sum_{fuels} \left(-\frac{\sum_i {\Delta H_f^0}_i -
\sum_j {\Delta H_f^0}_j }
{M_{fuel}} \cdot x_{fuel} \right)\\
\forall i \in \text{reation products},\\
\forall j \in \text{reation educts},\\
\forall fuel \in \text{fuels},\\
\Delta H_f^0: \text{molar formation enthalpy},\\
x_{fuel}: \text{mass fraction of fuel in fuel mixture}
"""
hf = {}
hf['hydrogen'] = 0
hf['methane'] = -74.85
hf['ethane'] = -84.68
hf['propane'] = -103.8
hf['butane'] = -124.51
hf['O2'] = 0
hf['CO2'] = -393.5
# water (gaseous)
hf['H2O'] = -241.8
lhv = 0
for f, x in self.fuel.val.items():
molar_masses[f] = CP.PropsSI('M', f)
fl = set(list(hf.keys())).intersection(
set([a.replace(' ', '') for a in CP.get_aliases(f)]))
if len(fl) == 0:
continue
if list(fl)[0] in self.fuels():
structure = fluid_structure(f)
n = {}
for el in ['C', 'H', 'O']:
if el in structure.keys():
n[el] = structure[el]
else:
n[el] = 0
lhv += (-(n['H'] / 2 * hf['H2O'] + n['C'] * hf['CO2'] -
((n['C'] + n['H'] / 4) * hf['O2'] +
hf[list(fl)[0]])) / molar_masses[f] * 1000) * x
return lhv
def stoich_flue_gas(self, nw):
r"""
Calculate the fluid composition of the stoichiometric flue gas.
- uses one mole of fuel as reference quantity and :math:`\lambda=1`
for stoichiometric flue gas calculation (no oxygen in flue gas)
- calculate molar quantities of (reactive) fuel components to determine
water and carbondioxide mass fraction in flue gas
- calculate required molar quantity for oxygen and required fresh
air mass
- calculate residual mass fractions for non reactive components of
fresh air in the flue gas
- calculate flue gas fluid composition
- generate custom fluid porperties
Reactive components in fuel
.. math::
m_{fuel} = \frac{1}{M_{fuel}}\\
m_{CO_2} = \sum_{i} \frac{x_{i} \cdot m_{fuel} \cdot num_{C,i}
\cdot M_{CO_{2}}}{M_{i}}\\
m_{H_{2}O} = \sum_{i} \frac{x_{i} \cdot m_{fuel} \cdot
num_{H,i} \cdot M_{H_{2}O}}{2 \cdot M_{i}}\\
\forall i \in \text{fuels in fuel vector},\\
num = \text{number of atoms in molecule}
Other components of fuel vector
.. math::
m_{fg,j} = x_{j} \cdot m_{fuel}\\
\forall j \in \text{non fuels in fuel vecotr, e.g. } CO_2,\\
m_{fg,j} = \text{mass of fluid component j in flue gas}
Non-reactive components in air
.. math::
n_{O_2} = \left( \frac{m_{CO_2}}{M_{CO_2}} +
\frac{m_{H_{2}O}}
{0,5 \cdot M_{H_{2}O}} \right) \cdot \lambda,\\
n_{O_2} = \text{mol of oxygen required}\\
m_{air} = \frac{n_{O_2} \cdot M_{O_2}}{x_{O_{2}, air}},\\
m_{air} = \text{required total air mass}\\
m_{fg,j} = x_{j, air} \cdot m_{air}\\
m_{fg, O_2} = 0,\\
m_{fg,j} = \text{mass of fluid component j in flue gas}
Flue gas composition
.. math::
x_{fg,j} = \frac{m_{fg, j}}{m_{air} + m_{fuel}}
Parameters
----------
nw : tespy.networks.network.Network
TESPy network to generate stoichiometric flue gas for.
"""
lamb = 1
n_fuel = 1
m_fuel = 1 / molar_mass_flow(self.fuel.val) * n_fuel
m_fuel_fg = m_fuel
m_co2 = 0
m_h2o = 0
molar_masses[self.h2o] = CP.PropsSI('M', self.h2o)
molar_masses[self.co2] = CP.PropsSI('M', self.co2)
molar_masses[self.o2] = CP.PropsSI('M', self.o2)
self.fg = {}
self.fg[self.co2] = 0
self.fg[self.h2o] = 0
for f, x in self.fuel.val.items():
fl = set(list(self.fuels())).intersection(
set([a.replace(' ', '') for a in CP.get_aliases(f)]))
if len(fl) == 0:
if f in self.fg.keys():
self.fg[f] += x * m_fuel
else:
self.fg[f] = x * m_fuel
else:
n_fluid = x * m_fuel / molar_masses[f]
m_fuel_fg -= n_fluid * molar_masses[f]
structure = fluid_structure(f)
n = {}
for el in ['C', 'H', 'O']:
if el in structure.keys():
n[el] = structure[el]
else:
n[el] = 0
m_co2 += n_fluid * n['C'] * molar_masses[self.co2]
m_h2o += n_fluid * n['H'] / 2 * molar_masses[self.h2o]
self.fg[self.co2] += m_co2
self.fg[self.h2o] += m_h2o
n_o2 = (m_co2 / molar_masses[self.co2] +
0.5 * m_h2o / molar_masses[self.h2o]) * lamb
m_air = n_o2 * molar_masses[self.o2] / self.air.val[self.o2]
self.air_min = m_air / m_fuel
for f, x in self.air.val.items():
if f != self.o2:
if f in self.fg.keys():
self.fg[f] += m_air * x
else:
self.fg[f] = m_air * x
m_fg = m_fuel + m_air
for f in self.fg.keys():
self.fg[f] /= m_fg
if not self.path.is_set:
self.path.val = None
TESPyFluid(
self.fuel_alias.val, self.fuel.val, [1000, nw.p_range_SI[1]],
path=self.path.val)
TESPyFluid(
self.fuel_alias.val + '_fg', self.fg, [1000, nw.p_range_SI[1]],
path=self.path.val)
msg = (
'Generated lookup table for ' + self.fuel_alias.val + ' and for '
'stoichiometric flue gas at component ' + self.label + '.')
logging.debug(msg)
if self.air_alias.val not in ['Air', 'air']:
TESPyFluid(
self.air_alias.val, self.air.val, [1000, nw.p_range_SI[1]],
path=self.path.val)
msg = ('Generated lookup table for ' + self.air_alias.val +
' at stoichiometric combustion chamber ' + self.label + '.')
else:
msg = ('Using CoolProp air at stoichiometric combustion chamber ' +
self.label + '.')
logging.debug(msg)