Source code for tespy.components.combustion.diabatic

# -*- coding: utf-8

"""Module of class CombustionChamber.


This file is part of project TESPy (github.com/oemof/tespy). It's copyrighted
by the contributors recorded in the version control history of the file,
available from its original location
tespy/components/combustion/diabatic.py

SPDX-License-Identifier: MIT
"""

import numpy as np

from tespy.components import CombustionChamber
from tespy.components.component import component_registry
from tespy.tools import logger
from tespy.tools.data_containers import ComponentProperties as dc_cp
from tespy.tools.document_models import generate_latex_eq
from tespy.tools.fluid_properties import h_mix_pT


[docs] @component_registry class DiabaticCombustionChamber(CombustionChamber): r""" The class CombustionChamber is parent class of all combustion components. **Mandatory Equations** - :py:meth:`tespy.components.combustion.base.CombustionChamber.mass_flow_func` - :py:meth:`tespy.components.combustion.base.CombustionChamber.combustion_pressure_func` - :py:meth:`tespy.components.combustion.base.CombustionChamber.stoichiometry` **Optional Equations** - :py:meth:`tespy.components.combustion.base.CombustionChamber.lambda_func` - :py:meth:`tespy.components.combustion.base.CombustionChamber.ti_func` - :py:meth:`tespy.components.combustion.diabatic.DiabaticCombustionChamber.energy_balance_func` - :py:meth:`tespy.components.combustion.diabatic.DiabaticCombustionChamber.pr_func` Available fuels - methane, ethane, propane, butane, hydrogen Inlets/Outlets - in1, in2 - out1 Image .. image:: /api/_images/CombustionChamber.svg :alt: flowsheet of the combustion chamber :align: center :class: only-light .. image:: /api/_images/CombustionChamber_darkmode.svg :alt: flowsheet of the combustion chamber :align: center :class: only-dark .. note:: The fuel and the air components can be connected to either of the inlets. The pressure of inlet 2 is disconnected from the pressure of inlet 1. A warning is prompted, if the pressure at inlet 2 is lower than the pressure at inlet 1. Parameters ---------- label : str The label of the component. design : list List containing design parameters (stated as String). offdesign : list List containing offdesign parameters (stated as String). design_path : str Path to the components design case. local_offdesign : boolean Treat this component in offdesign mode in a design calculation. local_design : boolean Treat this component in design mode in an offdesign calculation. char_warnings : boolean Ignore warnings on default characteristics usage for this component. printout : boolean Include this component in the network's results printout. lamb : float, dict Actual oxygen to stoichiometric oxygen ratio, :math:`\lambda/1`. ti : float, dict Thermal input, (:math:`{LHV \cdot \dot{m}_f}`), :math:`ti/\text{W}`. eta : float, dict Combustion thermal efficiency, :math:`\eta`. Heat loss calculation based on share of thermal input. pr : float, dict Pressure ratio of outlet 1 to inlet 1, :math:`pr`. Note ---- For more information on the usage of the combustion chamber see the examples section on github or look for the combustion chamber tutorials at tespy.readthedocs.io. Example ------- The combustion chamber calculates energy input due to combustion as well as the flue gas composition based on the type of fuel and the amount of oxygen supplied. In this example a mixture of methane, hydrogen and carbondioxide is used as fuel. >>> from tespy.components import Sink, Source, DiabaticCombustionChamber >>> from tespy.connections import Connection >>> from tespy.networks import Network >>> from tespy.tools.fluid_properties import T_sat_p >>> import shutil >>> nw = Network(p_unit='bar', T_unit='C', iterinfo=False) >>> amb = Source('ambient air') >>> sf = Source('fuel') >>> fg = Sink('flue gas outlet') >>> comb = DiabaticCombustionChamber('combustion chamber') >>> comb.component() 'diabatic combustion chamber' >>> amb_comb = Connection(amb, 'out1', comb, 'in1') >>> sf_comb = Connection(sf, 'out1', comb, 'in2') >>> comb_fg = Connection(comb, 'out1', fg, 'in1') >>> nw.add_conns(sf_comb, amb_comb, comb_fg) Specify the thermal input of the combustion chamber. At the given fluid compositions this determines the mass flow of the fuel. The outlet temperature of the flue gas determines the ratio of oxygen to fuel mass flow. In contrast to the simple combustion chamber, this component does allow for a pressure drop. Therefore the outlet pressure or the pressure ratio of the combustion chamber must be specified. Since the component is not adiabatic, an efficiency value :code:`eta` can be supplied to account for heat loss to the ambient. First, we specify :code:`eta=1` and expect identical lambda or outlet temperature as in an adiabatic combustion chamber. >>> comb.set_attr(ti=500000, pr=0.95, eta=1, lamb=1.5) >>> amb_comb.set_attr(p=1.2, T=20, fluid={'Ar': 0.0129, 'N2': 0.7553, ... 'CO2': 0.0004, 'O2': 0.2314}) >>> sf_comb.set_attr(T=25, fluid={'CO2': 0.03, 'H2': 0.01, 'CH4': 0.96}, p=1.3) >>> nw.solve('design') >>> comb_fg.set_attr(T=1200) >>> comb.set_attr(lamb=None) >>> nw.solve('design') >>> round(comb.lamb.val, 3) 2.014 >>> round(comb_fg.p.val, 2) 1.14 Instead of the pressure ration, we can also specify the outlet pressure. The pressure ratio is the ratio or pressure at the outlet to the pressure at the inlet 1 (ambient air inlet in this example). >>> comb.set_attr(pr=None) >>> comb_fg.set_attr(p=1) >>> nw.solve('design') >>> round(comb.pr.val, 3) 0.833 We can change lambda to a specific value and unset the flue gas temperature: >>> comb.set_attr(lamb=2) >>> comb_fg.set_attr(T=None) >>> nw.solve('design') >>> round(comb_fg.T.val, 1) 1206.5 Now, if we change the efficiency value, e.g. to 0.9, a total of 10 % of heat respective to the thermal input will be transferred to the ambient. Note, that the heat loss :code:`Q_loss` has a negative value as it is extracted from the system. >>> eta = 0.9 >>> comb.set_attr(eta=eta) >>> nw.solve('design') >>> round(comb.Q_loss.val, 0) -50000.0 >>> round(comb.ti.val * comb.eta.val, 0) 450000.0 """
[docs] @staticmethod def component(): return 'diabatic combustion chamber'
[docs] def get_parameters(self): return { 'lamb': dc_cp( min_val=1, deriv=self.lambda_deriv, func=self.lambda_func, latex=self.lambda_func_doc, num_eq=1), 'ti': dc_cp( min_val=0, deriv=self.ti_deriv, func=self.ti_func, latex=self.ti_func_doc, num_eq=1), 'pr': dc_cp( min_val=0, deriv=self.pr_deriv, func=self.pr_func, latex=self.pr_func_doc, num_eq=1), 'eta': dc_cp( max_val=1, min_val=0, deriv=self.energy_balance_deriv, func=self.energy_balance_func, latex=self.energy_balance_func_doc, num_eq=1), 'Q_loss': dc_cp(max_val=0, is_result=True) }
[docs] def get_mandatory_constraints(self): return { k: v for k, v in super().get_mandatory_constraints().items() if k in ["mass_flow_constraints", "stoichiometry_constraints"] }
[docs] def pr_func(self): r""" Equation for pressure drop. Returns ------- residual : float Residual value of equation. .. math:: 0 = p_\mathrm{in,1} \cdot pr - p_\mathrm{out,1} """ return self.inl[0].p.val_SI * self.pr.val - self.outl[0].p.val_SI
[docs] def pr_func_doc(self, label): r""" Equation for inlet pressure equality. Parameters ---------- label : str Label for equation. Returns ------- latex : str LaTeX code of equations applied. """ latex = ( r'\begin{split}' + '\n' r'0 = & p_\mathrm{in,1} \cdot pr - p_\mathrm{out,1}\\' + '\n' r'\end{split}') return generate_latex_eq(self, latex, label)
[docs] def pr_deriv(self, increment_filter, k): r""" Calculate the partial derivatives for combustion pressure ratio. Parameters ---------- increment_filter : ndarray Matrix for filtering non-changing variables. k : int Position of equation in Jacobian matrix. """ i = self.inl[0] o = self.outl[0] if self.is_variable(i.p): self.jacobian[k, i.p.J_col] = self.pr.val if self.is_variable(o.p): self.jacobian[k, o.p.J_col] = -1
[docs] def energy_balance_func(self): r""" Calculate the energy balance of the diabatic combustion chamber. Returns ------- residual : float Residual value of equation. .. math:: \begin{split} 0 = & \sum_i \dot{m}_{in,i} \cdot \left( h_{in,i} - h_{in,i,ref} \right)\\ & -\dot{m}_{out,2}\cdot\left( h_{out,1}-h_{out,1,ref} \right)\\ & + LHV_{fuel} \cdot\left(\sum_i\dot{m}_{in,i}\cdot x_{fuel,in,i}- \dot{m}_{out,1} \cdot x_{fuel} \right) \cdot \eta \end{split}\\ \forall i \in \text{inlets} Note ---- The temperature for the reference state is set to 25 °C, thus the water may be liquid. In order to make sure, the state is referring to the lower heating value, the state of the water in the flue gas is fored to gaseous. - Reference temperature: 298.15 K. - Reference pressure: 1 bar. """ T_ref = 298.15 p_ref = 1e5 res = 0 for i in self.inl: i.build_fluid_data() res += i.m.val_SI * ( i.h.val_SI - h_mix_pT(p_ref, T_ref, i.fluid_data, mixing_rule="forced-gas") ) for o in self.outl: o.build_fluid_data() res -= o.m.val_SI * ( o.h.val_SI - h_mix_pT(p_ref, T_ref, o.fluid_data, mixing_rule="forced-gas") ) res += self.calc_ti() * self.eta.val return res
[docs] def energy_balance_func_doc(self, label): r""" Calculate the energy balance of the diabatic combustion chamber. Parameters ---------- label : str Label for equation. Returns ------- latex : str LaTeX code of equations applied. """ latex = ( r'\begin{split}' + '\n' r'0 = & \sum_i \dot{m}_{\mathrm{in,}i} \cdot\left( ' r'h_{\mathrm{in,}i} - h_{\mathrm{in,}i\mathrm{,ref}} \right) -' r'\dot{m}_\mathrm{out,1}\cdot\left( h_\mathrm{out,1}' r' - h_\mathrm{out,1,ref}\right)\\' + '\n' r'& + LHV_{fuel} \cdot \left(\sum_i \dot{m}_{\mathrm{in,}i} ' r'\cdot x_{fuel\mathrm{,in,}i} - \dot{m}_\mathrm{out,1} ' r'\cdot x_{fuel\mathrm{,out,1}} \right) \cdot \eta\\' + '\n' r'& \forall i \in \text{inlets}\\' r'& T_\mathrm{ref}=\unit[298.15]{K}' r'\;p_\mathrm{ref}=\unit[10^5]{Pa}\\' '\n' + r'\end{split}' ) return generate_latex_eq(self, latex, label)
[docs] def calc_parameters(self): r"""Postprocessing parameter calculation.""" super().calc_parameters() T_ref = 298.15 p_ref = 1e5 res = 0 for i in self.inl: i.build_fluid_data() res += i.m.val_SI * ( i.h.val_SI - h_mix_pT(p_ref, T_ref, i.fluid_data, mixing_rule="forced-gas") ) for o in self.outl: o.build_fluid_data() res -= o.m.val_SI * ( o.h.val_SI - h_mix_pT(p_ref, T_ref, o.fluid_data, mixing_rule="forced-gas") ) self.eta.val = -res / self.ti.val self.Q_loss.val = -(1 - self.eta.val) * self.ti.val self.pr.val = self.outl[0].p.val_SI / self.inl[0].p.val_SI for num, i in enumerate(self.inl): if i.p.val < self.outl[0].p.val: msg = ( f"The pressure at inlet {num + 1} is lower than the " f"pressure at the outlet of component {self.label}." ) logger.warning(msg)
[docs] def exergy_balance(self, T0): self.E_P = self.outl[0].Ex_physical - ( self.inl[0].Ex_physical + self.inl[1].Ex_physical ) self.E_F = ( self.inl[0].Ex_chemical + self.inl[1].Ex_chemical - self.outl[0].Ex_chemical ) self.E_D = self.E_F - self.E_P self.epsilon = self._calc_epsilon() self.E_bus = {"chemical": np.nan, "physical": np.nan, "massless": np.nan}