solph.components._generic_chp.GenericCHPBlock.__init__() - Code Metrics - Inspection of "Make solph work with pyomo >= 0.6" - oemof/oemof-solph - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — dev (#821)

by Uwe

created 2022-02-11 15:35 UTC

GenericCHPBlock.init() A

↳ Parent: solph.components._generic_chp

Complexity

Conditions

Size

Total Lines	2
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Importance

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Metric	Value
eloc	2
dl	0
loc	2
rs	10
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cc	1
nop	3

# -*- coding: utf-8 -

"""
GenericCHP and associated individual constraints (blocks) and groupings.

SPDX-FileCopyrightText: Uwe Krien <[email protected]>
SPDX-FileCopyrightText: Simon Hilpert
SPDX-FileCopyrightText: Cord Kaldemeyer
SPDX-FileCopyrightText: Patrik Schönfeldt
SPDX-FileCopyrightText: FranziPl
SPDX-FileCopyrightText: jnnr
SPDX-FileCopyrightText: Stephan Günther
SPDX-FileCopyrightText: FabianTU
SPDX-FileCopyrightText: Johannes Röder

SPDX-License-Identifier: MIT

"""

import numpy as np
from oemof.network import network
from pyomo.core.base.block import ScalarBlock
from pyomo.environ import Binary
from pyomo.environ import Constraint
from pyomo.environ import NonNegativeReals
from pyomo.environ import Set
from pyomo.environ import Var

from oemof.solph._plumbing import sequence as solph_sequence


class GenericCHP(network.Transformer):
    r"""
    Component `GenericCHP` to model combined heat and power plants.

    Can be used to model (combined cycle) extraction or back-pressure turbines
    and used a mixed-integer linear formulation. Thus, it induces more
    computational effort than the `ExtractionTurbineCHP` for the
    benefit of higher accuracy.

    The full set of equations is described in:
    Mollenhauer, E., Christidis, A. & Tsatsaronis, G.
    Evaluation of an energy- and exergy-based generic modeling
    approach of combined heat and power plants
    Int J Energy Environ Eng (2016) 7: 167.
    https://doi.org/10.1007/s40095-016-0204-6

    For a general understanding of (MI)LP CHP representation, see:
    Fabricio I. Salgado, P.
    Short - Term Operation Planning on Cogeneration Systems: A Survey
    Electric Power Systems Research (2007)
    Electric Power Systems Research
    Volume 78, Issue 5, May 2008, Pages 835-848
    https://doi.org/10.1016/j.epsr.2007.06.001

    Note
    ----
    An adaption for the flow parameter `H_L_FG_share_max` has been made to
    set the flue gas losses at maximum heat extraction `H_L_FG_max` as share of
    the fuel flow `H_F` e.g. for combined cycle extraction turbines.
    The flow parameter `H_L_FG_share_min` can be used to set the flue gas
    losses at minimum heat extraction `H_L_FG_min` as share of
    the fuel flow `H_F` e.g. for motoric CHPs.
    The boolean component parameter `back_pressure` can be set to model
    back-pressure characteristics.

    Also have a look at the examples on how to use it.

    Parameters
    ----------
    fuel_input : dict
        Dictionary with key-value-pair of `oemof.Bus` and `oemof.Flow` object
        for the fuel input.
    electrical_output : dict
        Dictionary with key-value-pair of `oemof.Bus` and `oemof.Flow` object
        for the electrical output. Related parameters like `P_max_woDH` are
        passed as attributes of the `oemof.Flow` object.
    heat_output : dict
        Dictionary with key-value-pair of `oemof.Bus` and `oemof.Flow` object
        for the heat output. Related parameters like `Q_CW_min` are passed as
        attributes of the `oemof.Flow` object.
    Beta : list of numerical values
        Beta values in same dimension as all other parameters (length of
        optimization period).
    back_pressure : boolean
        Flag to use back-pressure characteristics. Set to `True` and
        `Q_CW_min` to zero for back-pressure turbines. See paper above for more
        information.

    Note
    ----
    The following sets, variables, constraints and objective parts are created
     * :py:class:`~oemof.solph.components._generic_chp.GenericCHPBlock`

    Examples
    --------
    >>> from oemof import solph
    >>> bel = solph.buses.Bus(label='electricityBus')
    >>> bth = solph.buses.Bus(label='heatBus')
    >>> bgas = solph.buses.Bus(label='commodityBus')
    >>> ccet = solph.components.GenericCHP(
    ...    label='combined_cycle_extraction_turbine',
    ...    fuel_input={bgas: solph.flows.Flow(
    ...        H_L_FG_share_max=[0.183])},
    ...    electrical_output={bel: solph.flows.Flow(
    ...        P_max_woDH=[155.946],
    ...        P_min_woDH=[68.787],
    ...        Eta_el_max_woDH=[0.525],
    ...        Eta_el_min_woDH=[0.444])},
    ...    heat_output={bth: solph.flows.Flow(
    ...        Q_CW_min=[10.552])},
    ...    Beta=[0.122], back_pressure=False)
    >>> type(ccet)
    <class 'oemof.solph.components._generic_chp.GenericCHP'>
    """

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.fuel_input = kwargs.get("fuel_input")
        self.electrical_output = kwargs.get("electrical_output")
        self.heat_output = kwargs.get("heat_output")
        self.Beta = solph_sequence(kwargs.get("Beta"))
        self.back_pressure = kwargs.get("back_pressure")
        self._alphas = None

        # map specific flows to standard API
        fuel_bus = list(self.fuel_input.keys())[0]
        fuel_flow = list(self.fuel_input.values())[0]
        fuel_bus.outputs.update({self: fuel_flow})

        self.outputs.update(kwargs.get("electrical_output"))
        self.outputs.update(kwargs.get("heat_output"))

    def _calculate_alphas(self):
        """
        Calculate alpha coefficients.

        A system of linear equations is created from passed capacities and
        efficiencies and solved to calculate both coefficients.
        """
        alphas = [[], []]

        eb = list(self.electrical_output.keys())[0]

        attrs = [
            self.electrical_output[eb].P_min_woDH,
            self.electrical_output[eb].Eta_el_min_woDH,
            self.electrical_output[eb].P_max_woDH,
            self.electrical_output[eb].Eta_el_max_woDH,
        ]

        length = [len(a) for a in attrs if not isinstance(a, (int, float))]
        max_length = max(length)

        if all(len(a) == max_length for a in attrs):
            if max_length == 0:
                max_length += 1  # increment dimension for scalars from 0 to 1
            for i in range(0, max_length):
                A = np.array(
                    [
                        [1, self.electrical_output[eb].P_min_woDH[i]],
                        [1, self.electrical_output[eb].P_max_woDH[i]],
                    ]
                )
                b = np.array(
                    [
                        self.electrical_output[eb].P_min_woDH[i]
                        / self.electrical_output[eb].Eta_el_min_woDH[i],
                        self.electrical_output[eb].P_max_woDH[i]
                        / self.electrical_output[eb].Eta_el_max_woDH[i],
                    ]
                )
                x = np.linalg.solve(A, b)
                alphas[0].append(x[0])
                alphas[1].append(x[1])
        else:
            error_message = (
                "Attributes to calculate alphas "
                + "must be of same dimension."
            )
            raise ValueError(error_message)

        self._alphas = alphas

    @property
    def alphas(self):
        """Compute or return the _alphas attribute."""
        if self._alphas is None:
            self._calculate_alphas()
        return self._alphas

    def constraint_group(self):
        return GenericCHPBlock


class GenericCHPBlock(ScalarBlock):
    r"""
    Block for the relation of the :math:`n` nodes with
    type class:`.GenericCHP`.

    **The following constraints are created:**

    .. _GenericCHP-equations1-10:

    .. math::
        &
        (1)\qquad \dot{H}_F(t) = fuel\ input \\
        &
        (2)\qquad \dot{Q}(t) = heat\ output \\
        &
        (3)\qquad P_{el}(t) = power\ output\\
        &
        (4)\qquad \dot{H}_F(t) = \alpha_0(t) \cdot Y(t) + \alpha_1(t) \cdot
        P_{el,woDH}(t)\\
        &
        (5)\qquad \dot{H}_F(t) = \alpha_0(t) \cdot Y(t) + \alpha_1(t) \cdot
        ( P_{el}(t) + \beta \cdot \dot{Q}(t) )\\
        &
        (6)\qquad \dot{H}_F(t) \leq Y(t) \cdot
        \frac{P_{el, max, woDH}(t)}{\eta_{el,max,woDH}(t)}\\
        &
        (7)\qquad \dot{H}_F(t) \geq Y(t) \cdot
        \frac{P_{el, min, woDH}(t)}{\eta_{el,min,woDH}(t)}\\
        &
        (8)\qquad \dot{H}_{L,FG,max}(t) = \dot{H}_F(t) \cdot
        \dot{H}_{L,FG,sharemax}(t)\\
        &
        (9)\qquad \dot{H}_{L,FG,min}(t) = \dot{H}_F(t) \cdot
        \dot{H}_{L,FG,sharemin}(t)\\
        &
        (10)\qquad P_{el}(t) + \dot{Q}(t) + \dot{H}_{L,FG,max}(t) +
        \dot{Q}_{CW, min}(t) \cdot Y(t) = / \leq \dot{H}_F(t)\\

    where :math:`= / \leq` depends on the CHP being back pressure or not.

    The coefficients :math:`\alpha_0` and :math:`\alpha_1`
    can be determined given the efficiencies maximal/minimal load:

    .. math::
        &
        \eta_{el,max,woDH}(t) = \frac{P_{el,max,woDH}(t)}{\alpha_0(t)
        \cdot Y(t) + \alpha_1(t) \cdot P_{el,max,woDH}(t)}\\
        &
        \eta_{el,min,woDH}(t) = \frac{P_{el,min,woDH}(t)}{\alpha_0(t)
        \cdot Y(t) + \alpha_1(t) \cdot P_{el,min,woDH}(t)}\\


    **For the attribute** :math:`\dot{H}_{L,FG,min}` **being not None**,
    e.g. for a motoric CHP, **the following is created:**

        **Constraint:**

    .. _GenericCHP-equations11:

    .. math::
        &
        (11)\qquad P_{el}(t) + \dot{Q}(t) + \dot{H}_{L,FG,min}(t) +
        \dot{Q}_{CW, min}(t) \cdot Y(t) \geq \dot{H}_F(t)\\[10pt]

    The symbols used are defined as follows (with Variables (V) and Parameters (P)):

    =============================== ======================= ==== =======================
    math. symbol                    attribute               type explanation
    =============================== ======================= ==== =======================
    :math:`\dot{H}_{F}`             `H_F[n,t]`              V    input of enthalpy
                                                                         through fuel input
    :math:`P_{el}`                  `P[n,t]`                V    provided
                                                                         electric power
    :math:`P_{el,woDH}`             `P_woDH[n,t]`           V    electric power without
                                                                         district heating
    :math:`P_{el,min,woDH}`         `P_min_woDH[n,t]`       P    min. electric power
                                                                         without district heating
    :math:`P_{el,max,woDH}`         `P_max_woDH[n,t]`       P    max. electric power
                                                                         without district heating
    :math:`\dot{Q}`                 `Q[n,t]`                V    provided heat

    :math:`\dot{Q}_{CW, min}`       `Q_CW_min[n,t]`         P    minimal therm. condenser
                                                                         load to cooling water
    :math:`\dot{H}_{L,FG,min}`      `H_L_FG_min[n,t]`       V    flue gas enthalpy loss
                                                                         at min heat extraction
    :math:`\dot{H}_{L,FG,max}`      `H_L_FG_max[n,t]`       V    flue gas enthalpy loss
                                                                         at max heat extraction
    :math:`\dot{H}_{L,FG,sharemin}` `H_L_FG_share_min[n,t]` P    share of flue gas loss
                                                                         at min heat extraction
    :math:`\dot{H}_{L,FG,sharemax}` `H_L_FG_share_max[n,t]` P    share of flue gas loss
                                                                         at max heat extraction
    :math:`Y`                       `Y[n,t]`                V    status variable
                                                                         on/off
    :math:`\alpha_0`                `n.alphas[0][n,t]`      P    coefficient
                                                                         describing efficiency
    :math:`\alpha_1`                `n.alphas[1][n,t]`      P    coefficient
                                                                         describing efficiency
    :math:`\beta`                   `Beta[n,t]`             P    power loss index

    :math:`\eta_{el,min,woDH}`      `Eta_el_min_woDH[n,t]`  P    el. eff. at min. fuel
                                                                         flow w/o distr. heating
    :math:`\eta_{el,max,woDH}`      `Eta_el_max_woDH[n,t]`  P    el. eff. at max. fuel
                                                                         flow w/o distr. heating
    =============================== ======================= ==== =======================

    """  # noqa: E501
    CONSTRAINT_GROUP = True

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    def _create(self, group=None):
        """
        Create constraints for GenericCHPBlock.

        Parameters
        ----------
        group : list
            List containing `GenericCHP` objects.
            e.g. groups=[ghcp1, gchp2,..]
        """
        m = self.parent_block()

        if group is None:
            return None

        self.GENERICCHPS = Set(initialize=[n for n in group])

        # variables
        self.H_F = Var(self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals)
        self.H_L_FG_max = Var(
            self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals
        )
        self.H_L_FG_min = Var(
            self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals
        )
        self.P_woDH = Var(
            self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals
        )
        self.P = Var(self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals)
        self.Q = Var(self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals)
        self.Y = Var(self.GENERICCHPS, m.TIMESTEPS, within=Binary)

        # constraint rules
        def _H_flow_rule(block, n, t):
            """Link fuel consumption to component inflow."""
            expr = 0
            expr += self.H_F[n, t]
            expr += -m.flow[list(n.fuel_input.keys())[0], n, t]
            return expr == 0

        self.H_flow = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_H_flow_rule
        )

        def _Q_flow_rule(block, n, t):
            """Link heat flow to component outflow."""
            expr = 0
            expr += self.Q[n, t]
            expr += -m.flow[n, list(n.heat_output.keys())[0], t]
            return expr == 0

        self.Q_flow = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_Q_flow_rule
        )

        def _P_flow_rule(block, n, t):
            """Link power flow to component outflow."""
            expr = 0
            expr += self.P[n, t]
            expr += -m.flow[n, list(n.electrical_output.keys())[0], t]
            return expr == 0

        self.P_flow = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_P_flow_rule
        )

        def _H_F_1_rule(block, n, t):
            """Set P_woDH depending on H_F."""
            expr = 0
            expr += -self.H_F[n, t]
            expr += n.alphas[0][t] * self.Y[n, t]
            expr += n.alphas[1][t] * self.P_woDH[n, t]
            return expr == 0

        self.H_F_1 = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_H_F_1_rule
        )

        def _H_F_2_rule(block, n, t):
            """Determine relation between H_F, P and Q."""
            expr = 0
            expr += -self.H_F[n, t]
            expr += n.alphas[0][t] * self.Y[n, t]
            expr += n.alphas[1][t] * (self.P[n, t] + n.Beta[t] * self.Q[n, t])
            return expr == 0

        self.H_F_2 = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_H_F_2_rule
        )

        def _H_F_3_rule(block, n, t):
            """Set upper value of operating range via H_F."""
            expr = 0
            expr += self.H_F[n, t]
            expr += -self.Y[n, t] * (
                list(n.electrical_output.values())[0].P_max_woDH[t]
                / list(n.electrical_output.values())[0].Eta_el_max_woDH[t]
            )
            return expr <= 0

        self.H_F_3 = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_H_F_3_rule
        )

        def _H_F_4_rule(block, n, t):
            """Set lower value of operating range via H_F."""
            expr = 0
            expr += self.H_F[n, t]
            expr += -self.Y[n, t] * (
                list(n.electrical_output.values())[0].P_min_woDH[t]
                / list(n.electrical_output.values())[0].Eta_el_min_woDH[t]
            )
            return expr >= 0

        self.H_F_4 = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_H_F_4_rule
        )

        def _H_L_FG_max_rule(block, n, t):
            """Set max. flue gas loss as share fuel flow share."""
            expr = 0
            expr += -self.H_L_FG_max[n, t]
            expr += (
                self.H_F[n, t]
                * list(n.fuel_input.values())[0].H_L_FG_share_max[t]
            )
            return expr == 0

        self.H_L_FG_max_def = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_H_L_FG_max_rule
        )

        def _Q_max_res_rule(block, n, t):
            """Set maximum Q depending on fuel and electrical flow."""
            expr = 0
            expr += self.P[n, t] + self.Q[n, t] + self.H_L_FG_max[n, t]
            expr += list(n.heat_output.values())[0].Q_CW_min[t] * self.Y[n, t]
            expr += -self.H_F[n, t]
            # back-pressure characteristics or one-segment model
            if n.back_pressure is True:
                return expr == 0
            else:
                return expr <= 0

        self.Q_max_res = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_Q_max_res_rule
        )

        def _H_L_FG_min_rule(block, n, t):
            """Set min. flue gas loss as fuel flow share."""
            # minimum flue gas losses e.g. for motoric CHPs
            if getattr(
                list(n.fuel_input.values())[0], "H_L_FG_share_min", None
            ):
                expr = 0
                expr += -self.H_L_FG_min[n, t]
                expr += (
                    self.H_F[n, t]
                    * list(n.fuel_input.values())[0].H_L_FG_share_min[t]
                )
                return expr == 0
            else:
                return Constraint.Skip

        self.H_L_FG_min_def = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_H_L_FG_min_rule
        )

        def _Q_min_res_rule(block, n, t):
            """Set minimum Q depending on fuel and eletrical flow."""
            # minimum restriction for heat flows e.g. for motoric CHPs
            if getattr(
                list(n.fuel_input.values())[0], "H_L_FG_share_min", None
            ):
                expr = 0
                expr += self.P[n, t] + self.Q[n, t] + self.H_L_FG_min[n, t]
                expr += (
                    list(n.heat_output.values())[0].Q_CW_min[t] * self.Y[n, t]
                )
                expr += -self.H_F[n, t]
                return expr >= 0
            else:
                return Constraint.Skip

        self.Q_min_res = Constraint(
            self.GENERICCHPS, m.TIMESTEPS, rule=_Q_min_res_rule
        )

    def _objective_expression(self):
        r"""Objective expression for generic CHPs with no investment.

        Note: This adds nothing as variable costs are already
        added in the Block :class:`FlowBlock`.
        """
        if not hasattr(self, "GENERICCHPS"):
            return 0

        return 0


1			# -*- coding: utf-8 -
2
3			"""
4			GenericCHP and associated individual constraints (blocks) and groupings.
5
6			SPDX-FileCopyrightText: Uwe Krien <[email protected]>
7			SPDX-FileCopyrightText: Simon Hilpert
8			SPDX-FileCopyrightText: Cord Kaldemeyer
9			SPDX-FileCopyrightText: Patrik Schönfeldt
10			SPDX-FileCopyrightText: FranziPl
11			SPDX-FileCopyrightText: jnnr
12			SPDX-FileCopyrightText: Stephan Günther
13			SPDX-FileCopyrightText: FabianTU
14			SPDX-FileCopyrightText: Johannes Röder
15
16			SPDX-License-Identifier: MIT
17
18			"""
19
20			import numpy as np
21			from oemof.network import network
22			from pyomo.core.base.block import ScalarBlock
23			from pyomo.environ import Binary
24			from pyomo.environ import Constraint
25			from pyomo.environ import NonNegativeReals
26			from pyomo.environ import Set
27			from pyomo.environ import Var
28
29			from oemof.solph._plumbing import sequence as solph_sequence
30
31
32			class GenericCHP(network.Transformer):
33			r"""
34			Component `GenericCHP` to model combined heat and power plants.
35
36			Can be used to model (combined cycle) extraction or back-pressure turbines
37			and used a mixed-integer linear formulation. Thus, it induces more
38			computational effort than the `ExtractionTurbineCHP` for the
39			benefit of higher accuracy.
40
41			The full set of equations is described in:
42			Mollenhauer, E., Christidis, A. & Tsatsaronis, G.
43			Evaluation of an energy- and exergy-based generic modeling
44			approach of combined heat and power plants
45			Int J Energy Environ Eng (2016) 7: 167.
46			https://doi.org/10.1007/s40095-016-0204-6
47
48			For a general understanding of (MI)LP CHP representation, see:
49			Fabricio I. Salgado, P.
50			Short - Term Operation Planning on Cogeneration Systems: A Survey
51			Electric Power Systems Research (2007)
52			Electric Power Systems Research
53			Volume 78, Issue 5, May 2008, Pages 835-848
54			https://doi.org/10.1016/j.epsr.2007.06.001
55
56			Note
57			----
58			An adaption for the flow parameter `H_L_FG_share_max` has been made to
59			set the flue gas losses at maximum heat extraction `H_L_FG_max` as share of
60			the fuel flow `H_F` e.g. for combined cycle extraction turbines.
61			The flow parameter `H_L_FG_share_min` can be used to set the flue gas
62			losses at minimum heat extraction `H_L_FG_min` as share of
63			the fuel flow `H_F` e.g. for motoric CHPs.
64			The boolean component parameter `back_pressure` can be set to model
65			back-pressure characteristics.
66
67			Also have a look at the examples on how to use it.
68
69			Parameters
70			----------
71			fuel_input : dict
72			Dictionary with key-value-pair of `oemof.Bus` and `oemof.Flow` object
73			for the fuel input.
74			electrical_output : dict
75			Dictionary with key-value-pair of `oemof.Bus` and `oemof.Flow` object
76			for the electrical output. Related parameters like `P_max_woDH` are
77			passed as attributes of the `oemof.Flow` object.
78			heat_output : dict
79			Dictionary with key-value-pair of `oemof.Bus` and `oemof.Flow` object
80			for the heat output. Related parameters like `Q_CW_min` are passed as
81			attributes of the `oemof.Flow` object.
82			Beta : list of numerical values
83			Beta values in same dimension as all other parameters (length of
84			optimization period).
85			back_pressure : boolean
86			Flag to use back-pressure characteristics. Set to `True` and
87			`Q_CW_min` to zero for back-pressure turbines. See paper above for more
88			information.
89
90			Note
91			----
92			The following sets, variables, constraints and objective parts are created
93			* :py:class:`~oemof.solph.components._generic_chp.GenericCHPBlock`
94
95			Examples
96			--------
97			>>> from oemof import solph
98			>>> bel = solph.buses.Bus(label='electricityBus')
99			>>> bth = solph.buses.Bus(label='heatBus')
100			>>> bgas = solph.buses.Bus(label='commodityBus')
101			>>> ccet = solph.components.GenericCHP(
102			... label='combined_cycle_extraction_turbine',
103			... fuel_input={bgas: solph.flows.Flow(
104			... H_L_FG_share_max=[0.183])},
105			... electrical_output={bel: solph.flows.Flow(
106			... P_max_woDH=[155.946],
107			... P_min_woDH=[68.787],
108			... Eta_el_max_woDH=[0.525],
109			... Eta_el_min_woDH=[0.444])},
110			... heat_output={bth: solph.flows.Flow(
111			... Q_CW_min=[10.552])},
112			... Beta=[0.122], back_pressure=False)
113			>>> type(ccet)
114			<class 'oemof.solph.components._generic_chp.GenericCHP'>
115			"""
116
117			def __init__(self, args, *kwargs):
118			super().__init__(args, *kwargs)
119
120			self.fuel_input = kwargs.get("fuel_input")
121			self.electrical_output = kwargs.get("electrical_output")
122			self.heat_output = kwargs.get("heat_output")
123			self.Beta = solph_sequence(kwargs.get("Beta"))
124			self.back_pressure = kwargs.get("back_pressure")
125			self._alphas = None
126
127			# map specific flows to standard API
128			fuel_bus = list(self.fuel_input.keys())[0]
129			fuel_flow = list(self.fuel_input.values())[0]
130			fuel_bus.outputs.update({self: fuel_flow})
131
132			self.outputs.update(kwargs.get("electrical_output"))
133			self.outputs.update(kwargs.get("heat_output"))
134
135			def _calculate_alphas(self):
136			"""
137			Calculate alpha coefficients.
138
139			A system of linear equations is created from passed capacities and
140			efficiencies and solved to calculate both coefficients.
141			"""
142			alphas = [[], []]
143
144			eb = list(self.electrical_output.keys())[0]
145
146			attrs = [
147			self.electrical_output[eb].P_min_woDH,
148			self.electrical_output[eb].Eta_el_min_woDH,
149			self.electrical_output[eb].P_max_woDH,
150			self.electrical_output[eb].Eta_el_max_woDH,
151			]
152
153			length = [len(a) for a in attrs if not isinstance(a, (int, float))]
154			max_length = max(length)
155
156			if all(len(a) == max_length for a in attrs):
157			if max_length == 0:
158			max_length += 1 # increment dimension for scalars from 0 to 1
159			for i in range(0, max_length):
160			A = np.array(
161			[
162			[1, self.electrical_output[eb].P_min_woDH[i]],
163			[1, self.electrical_output[eb].P_max_woDH[i]],
164			]
165			)
166			b = np.array(
167			[
168			self.electrical_output[eb].P_min_woDH[i]
169			/ self.electrical_output[eb].Eta_el_min_woDH[i],
170			self.electrical_output[eb].P_max_woDH[i]
171			/ self.electrical_output[eb].Eta_el_max_woDH[i],
172			]
173			)
174			x = np.linalg.solve(A, b)
175			alphas[0].append(x[0])
176			alphas[1].append(x[1])
177			else:
178			error_message = (
179			"Attributes to calculate alphas "
180			+ "must be of same dimension."
181			)
182			raise ValueError(error_message)
183
184			self._alphas = alphas
185
186			@property
187			def alphas(self):
188			"""Compute or return the _alphas attribute."""
189			if self._alphas is None:
190			self._calculate_alphas()
191			return self._alphas
192
193			def constraint_group(self):
194			return GenericCHPBlock
195
196
197			class GenericCHPBlock(ScalarBlock):
198			r"""
199			Block for the relation of the :math:`n` nodes with
200			type class:`.GenericCHP`.
201
202			The following constraints are created:
203
204			.. _GenericCHP-equations1-10:
205
206			.. math::
207			&
208			(1)\qquad \dot{H}_F(t) = fuel\ input \\
209			&
210			(2)\qquad \dot{Q}(t) = heat\ output \\
211			&
212			(3)\qquad P_{el}(t) = power\ output\\
213			&
214			(4)\qquad \dot{H}_F(t) = \alpha_0(t) \cdot Y(t) + \alpha_1(t) \cdot
215			P_{el,woDH}(t)\\
216			&
217			(5)\qquad \dot{H}_F(t) = \alpha_0(t) \cdot Y(t) + \alpha_1(t) \cdot
218			( P_{el}(t) + \beta \cdot \dot{Q}(t) )\\
219			&
220			(6)\qquad \dot{H}_F(t) \leq Y(t) \cdot
221			\frac{P_{el, max, woDH}(t)}{\eta_{el,max,woDH}(t)}\\
222			&
223			(7)\qquad \dot{H}_F(t) \geq Y(t) \cdot
224			\frac{P_{el, min, woDH}(t)}{\eta_{el,min,woDH}(t)}\\
225			&
226			(8)\qquad \dot{H}_{L,FG,max}(t) = \dot{H}_F(t) \cdot
227			\dot{H}_{L,FG,sharemax}(t)\\
228			&
229			(9)\qquad \dot{H}_{L,FG,min}(t) = \dot{H}_F(t) \cdot
230			\dot{H}_{L,FG,sharemin}(t)\\
231			&
232			(10)\qquad P_{el}(t) + \dot{Q}(t) + \dot{H}_{L,FG,max}(t) +
233			\dot{Q}_{CW, min}(t) \cdot Y(t) = / \leq \dot{H}_F(t)\\
234
235			where :math:`= / \leq` depends on the CHP being back pressure or not.
236
237			The coefficients :math:`\alpha_0` and :math:`\alpha_1`
238			can be determined given the efficiencies maximal/minimal load:
239
240			.. math::
241			&
242			\eta_{el,max,woDH}(t) = \frac{P_{el,max,woDH}(t)}{\alpha_0(t)
243			\cdot Y(t) + \alpha_1(t) \cdot P_{el,max,woDH}(t)}\\
244			&
245			\eta_{el,min,woDH}(t) = \frac{P_{el,min,woDH}(t)}{\alpha_0(t)
246			\cdot Y(t) + \alpha_1(t) \cdot P_{el,min,woDH}(t)}\\
247
248
249			For the attribute :math:`\dot{H}_{L,FG,min}` being not None,
250			e.g. for a motoric CHP, the following is created:
251
252			Constraint:
253
254			.. _GenericCHP-equations11:
255
256			.. math::
257			&
258			(11)\qquad P_{el}(t) + \dot{Q}(t) + \dot{H}_{L,FG,min}(t) +
259			\dot{Q}_{CW, min}(t) \cdot Y(t) \geq \dot{H}_F(t)\\[10pt]
260
261			The symbols used are defined as follows (with Variables (V) and Parameters (P)):
262
263			=============================== ======================= ==== =======================
264			math. symbol attribute type explanation
265			=============================== ======================= ==== =======================
266			:math:`\dot{H}_{F}` `H_F[n,t]` V input of enthalpy
267			through fuel input
268			:math:`P_{el}` `P[n,t]` V provided
269			electric power
270			:math:`P_{el,woDH}` `P_woDH[n,t]` V electric power without
271			district heating
272			:math:`P_{el,min,woDH}` `P_min_woDH[n,t]` P min. electric power
273			without district heating
274			:math:`P_{el,max,woDH}` `P_max_woDH[n,t]` P max. electric power
275			without district heating
276			:math:`\dot{Q}` `Q[n,t]` V provided heat
277
278			:math:`\dot{Q}_{CW, min}` `Q_CW_min[n,t]` P minimal therm. condenser
279			load to cooling water
280			:math:`\dot{H}_{L,FG,min}` `H_L_FG_min[n,t]` V flue gas enthalpy loss
281			at min heat extraction
282			:math:`\dot{H}_{L,FG,max}` `H_L_FG_max[n,t]` V flue gas enthalpy loss
283			at max heat extraction
284			:math:`\dot{H}_{L,FG,sharemin}` `H_L_FG_share_min[n,t]` P share of flue gas loss
285			at min heat extraction
286			:math:`\dot{H}_{L,FG,sharemax}` `H_L_FG_share_max[n,t]` P share of flue gas loss
287			at max heat extraction
288			:math:`Y` `Y[n,t]` V status variable
289			on/off
290			:math:`\alpha_0` `n.alphas[0][n,t]` P coefficient
291			describing efficiency
292			:math:`\alpha_1` `n.alphas[1][n,t]` P coefficient
293			describing efficiency
294			:math:`\beta` `Beta[n,t]` P power loss index
295
296			:math:`\eta_{el,min,woDH}` `Eta_el_min_woDH[n,t]` P el. eff. at min. fuel
297			flow w/o distr. heating
298			:math:`\eta_{el,max,woDH}` `Eta_el_max_woDH[n,t]` P el. eff. at max. fuel
299			flow w/o distr. heating
300			=============================== ======================= ==== =======================
301
302			""" # noqa: E501
303			CONSTRAINT_GROUP = True
304
305			def __init__(self, args, *kwargs):
306			super().__init__(args, *kwargs)
307
308			def _create(self, group=None):
309			"""
310			Create constraints for GenericCHPBlock.
311
312			Parameters
313			----------
314			group : list
315			List containing `GenericCHP` objects.
316			e.g. groups=[ghcp1, gchp2,..]
317			"""
318			m = self.parent_block()
319
320			if group is None:
321			return None
322
323			self.GENERICCHPS = Set(initialize=[n for n in group])
324
325			# variables
326			self.H_F = Var(self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals)
327			self.H_L_FG_max = Var(
328			self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals
329			)
330			self.H_L_FG_min = Var(
331			self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals
332			)
333			self.P_woDH = Var(
334			self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals
335			)
336			self.P = Var(self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals)
337			self.Q = Var(self.GENERICCHPS, m.TIMESTEPS, within=NonNegativeReals)
338			self.Y = Var(self.GENERICCHPS, m.TIMESTEPS, within=Binary)
339
340			# constraint rules
341			def _H_flow_rule(block, n, t):
342			"""Link fuel consumption to component inflow."""
343			expr = 0
344			expr += self.H_F[n, t]
345			expr += -m.flow[list(n.fuel_input.keys())[0], n, t]
346			return expr == 0
347
348			self.H_flow = Constraint(
349			self.GENERICCHPS, m.TIMESTEPS, rule=_H_flow_rule
350			)
351
352			def _Q_flow_rule(block, n, t):
353			"""Link heat flow to component outflow."""
354			expr = 0
355			expr += self.Q[n, t]
356			expr += -m.flow[n, list(n.heat_output.keys())[0], t]
357			return expr == 0
358
359			self.Q_flow = Constraint(
360			self.GENERICCHPS, m.TIMESTEPS, rule=_Q_flow_rule
361			)
362
363			def _P_flow_rule(block, n, t):
364			"""Link power flow to component outflow."""
365			expr = 0
366			expr += self.P[n, t]
367			expr += -m.flow[n, list(n.electrical_output.keys())[0], t]
368			return expr == 0
369
370			self.P_flow = Constraint(
371			self.GENERICCHPS, m.TIMESTEPS, rule=_P_flow_rule
372			)
373
374			def _H_F_1_rule(block, n, t):
375			"""Set P_woDH depending on H_F."""
376			expr = 0
377			expr += -self.H_F[n, t]
378			expr += n.alphas[0][t] * self.Y[n, t]
379			expr += n.alphas[1][t] * self.P_woDH[n, t]
380			return expr == 0
381
382			self.H_F_1 = Constraint(
383			self.GENERICCHPS, m.TIMESTEPS, rule=_H_F_1_rule
384			)
385
386			def _H_F_2_rule(block, n, t):
387			"""Determine relation between H_F, P and Q."""
388			expr = 0
389			expr += -self.H_F[n, t]
390			expr += n.alphas[0][t] * self.Y[n, t]
391			expr += n.alphas[1][t] * (self.P[n, t] + n.Beta[t] * self.Q[n, t])
392			return expr == 0
393
394			self.H_F_2 = Constraint(
395			self.GENERICCHPS, m.TIMESTEPS, rule=_H_F_2_rule
396			)
397
398			def _H_F_3_rule(block, n, t):
399			"""Set upper value of operating range via H_F."""
400			expr = 0
401			expr += self.H_F[n, t]
402			expr += -self.Y[n, t] * (
403			list(n.electrical_output.values())[0].P_max_woDH[t]
404			/ list(n.electrical_output.values())[0].Eta_el_max_woDH[t]
405			)
406			return expr <= 0
407
408			self.H_F_3 = Constraint(
409			self.GENERICCHPS, m.TIMESTEPS, rule=_H_F_3_rule
410			)
411
412			def _H_F_4_rule(block, n, t):
413			"""Set lower value of operating range via H_F."""
414			expr = 0
415			expr += self.H_F[n, t]
416			expr += -self.Y[n, t] * (
417			list(n.electrical_output.values())[0].P_min_woDH[t]
418			/ list(n.electrical_output.values())[0].Eta_el_min_woDH[t]
419			)
420			return expr >= 0
421
422			self.H_F_4 = Constraint(
423			self.GENERICCHPS, m.TIMESTEPS, rule=_H_F_4_rule
424			)
425
426			def _H_L_FG_max_rule(block, n, t):
427			"""Set max. flue gas loss as share fuel flow share."""
428			expr = 0
429			expr += -self.H_L_FG_max[n, t]
430			expr += (
431			self.H_F[n, t]
432			* list(n.fuel_input.values())[0].H_L_FG_share_max[t]
433			)
434			return expr == 0
435
436			self.H_L_FG_max_def = Constraint(
437			self.GENERICCHPS, m.TIMESTEPS, rule=_H_L_FG_max_rule
438			)
439
440			def _Q_max_res_rule(block, n, t):
441			"""Set maximum Q depending on fuel and electrical flow."""
442			expr = 0
443			expr += self.P[n, t] + self.Q[n, t] + self.H_L_FG_max[n, t]
444			expr += list(n.heat_output.values())[0].Q_CW_min[t] * self.Y[n, t]
445			expr += -self.H_F[n, t]
446			# back-pressure characteristics or one-segment model
447			if n.back_pressure is True:
448			return expr == 0
449			else:
450			return expr <= 0
451
452			self.Q_max_res = Constraint(
453			self.GENERICCHPS, m.TIMESTEPS, rule=_Q_max_res_rule
454			)
455
456			def _H_L_FG_min_rule(block, n, t):
457			"""Set min. flue gas loss as fuel flow share."""
458			# minimum flue gas losses e.g. for motoric CHPs
459			if getattr(
460			list(n.fuel_input.values())[0], "H_L_FG_share_min", None
461			):
462			expr = 0
463			expr += -self.H_L_FG_min[n, t]
464			expr += (
465			self.H_F[n, t]
466			* list(n.fuel_input.values())[0].H_L_FG_share_min[t]
467			)
468			return expr == 0
469			else:
470			return Constraint.Skip
471
472			self.H_L_FG_min_def = Constraint(
473			self.GENERICCHPS, m.TIMESTEPS, rule=_H_L_FG_min_rule
474			)
475
476			def _Q_min_res_rule(block, n, t):
477			"""Set minimum Q depending on fuel and eletrical flow."""
478			# minimum restriction for heat flows e.g. for motoric CHPs
479			if getattr(
480			list(n.fuel_input.values())[0], "H_L_FG_share_min", None
481			):
482			expr = 0
483			expr += self.P[n, t] + self.Q[n, t] + self.H_L_FG_min[n, t]
484			expr += (
485			list(n.heat_output.values())[0].Q_CW_min[t] * self.Y[n, t]
486			)
487			expr += -self.H_F[n, t]
488			return expr >= 0
489			else:
490			return Constraint.Skip
491
492			self.Q_min_res = Constraint(
493			self.GENERICCHPS, m.TIMESTEPS, rule=_Q_min_res_rule
494			)
495
496			def _objective_expression(self):
497			r"""Objective expression for generic CHPs with no investment.
498
499			Note: This adds nothing as variable costs are already
500			added in the Block :class:`FlowBlock`.
501			"""
502			if not hasattr(self, "GENERICCHPS"):
503			return 0
504
505			return 0
506

oemof / oemof-solph

Pull Request — dev (#821)

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