Source code for tespy.components.nodes.base

# -*- coding: utf-8

"""Module of class NodeBase.


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/nodes/base.py

SPDX-License-Identifier: MIT
"""

from tespy.components.component import Component
from tespy.components.component import component_registry




@component_registry
class NodeBase(Component):
    """Class NodeBase is parent class for all components of submodule nodes."""



    @staticmethod
    def get_bypass_constraints():
        return {}




    def mass_flow_func(self):
        r"""
        Calculate the residual value for mass flow balance equation.

        Returns
        -------
        res : float
            Residual value of equation.

            .. math::

                0 = \sum \dot{m}_{in,i} - \sum \dot{m}_{out,j} \;
                \forall i \in inlets, \forall j \in outlets
        """
        res = 0
        for i in self.inl:
            res += i.m.val_SI
        for o in self.outl:
            res -= o.m.val_SI
        return res




    def mass_flow_dependents(self):
        return [c.m for c in self.inl + self.outl]




    def pressure_equality_func(self):
        r"""
        Calculate the residual values of pressure equality equations.

        Returns
        -------
        residual : list
            Vector with residual value for pressure equality equations.

            .. math::

                0 = p_{in,1} - p_{in,i}\forall i \in \text{inlets > 1}\\
                0 = p_{in,1} - p_{out,j}\forall j \in \text{outlets}
        """
        residual = []
        inl = []
        if self.num_i > 1:
            inl = self.inl[1:]
        for c in inl + self.outl:
            residual += [self.inl[0].p.val_SI - c.p.val_SI]
        return residual




    def pressure_structure_matrix(self, k):
        r"""
        Calculate partial derivatives for all pressure equations.
        """
        if self.num_i > 1:
            conns = self.inl[1:] + self.outl
        else:
            conns = self.outl

        for eq, conn in enumerate(conns):
            self._structure_matrix[k + eq, self.inl[0].p.sm_col] = 1
            self._structure_matrix[k + eq, conn.p.sm_col] = -1




    @staticmethod
    def initialise_source(c, key):
        r"""
        Return a starting value for pressure and enthalpy at outlet.

        Parameters
        ----------
        c : tespy.connections.connection.Connection
            Connection to perform initialisation on.

        key : str
            Fluid property to retrieve.

        Returns
        -------
        val : float
            Starting value for pressure/enthalpy in SI units.

            .. math::

                val = \begin{cases}
                10^5 & \text{key = 'p'}\\
                5 \cdot 10^5 & \text{key = 'h'}
                \end{cases}
        """
        if key == 'p':
            return 1e5
        elif key == 'h':
            return 5e5




    @staticmethod
    def initialise_target(c, key):
        r"""
        Return a starting value for pressure and enthalpy at inlet.

        Parameters
        ----------
        c : tespy.connections.connection.Connection
            Connection to perform initialisation on.

        key : str
            Fluid property to retrieve.

        Returns
        -------
        val : float
            Starting value for pressure/enthalpy in SI units.

            .. math::

                val = \begin{cases}
                10^5 & \text{key = 'p'}\\
                5 \cdot 10^5 & \text{key = 'h'}
                \end{cases}
        """
        if key == 'p':
            return 1e5
        elif key == 'h':
            return 5e5