Merge branch 'dev'

docs/conf.py

@@ -148,5 +148,6 @@
   r'https://doi.org/20.500.12738/6561',  # 08.01.2023: does not resolve anymore
   r'https://doi.org/10.1021/ie4033999',  # 28.02.2023: does not resolve anymore for some reason
   r'https://doi.org/10.1002/bbpc.19900940121',  # 13.03.2023 ...?
-  r' http://www.coolprop.org/fluid_properties/Incompressibles.html',  # 02.12.2023 ...?
+  r'http://www\.coolprop\.org/.*',  # 02.12.2023 ...?
+  r'https://github\.com/oemof/tespy/.*',  # 08.01.2024 ...?
 ]

docs/modules/fluid_properties.rst

@@ -60,14 +60,21 @@ Incompressible fluids
 If you are looking for heat transfer fluids, the list of incompressible
 `fluids <http://www.coolprop.org/fluid_properties/Incompressibles.html>`__
 might be interesting for you. In contrast to the pure fluids, the properties
-cover liquid state only. TESPy supports using pure incompressibles as well as
-the predefined mixtures.
+cover liquid state only.
 
 Fluid mixtures
 ++++++++++++++
-CoolProp provides a back end for predefined mixtures, which is rather instable
-using HEOS. If you want to use the mixture feature of CoolProp we recommend
-using the REFPROP back end instead.
+TESPy provides support for three types of mixtures:
+
+- ideal: Mixtures for gases only.
+- ideal-cond: Mixture for gases with condensation calculation for water share.
+- incompressible: Mixtures for incompressible fluids.
+
+Furthermore, CoolProp provides a back end for predefined mixtures, which is
+rather instable using HEOS. Using the CoolProp mixture back-end is not tested,
+reach out if you would like to support us in adopting the TESPy implementation.
+In general, to use the mixture feature of CoolProp we recommend using the
+REFPROP back end instead of HEOS.
 
 Using other engines
 -------------------

docs/modules/ude.rst

@@ -118,7 +118,7 @@ derivatives to mass flow are not zero.
     ...     c0 = self.conns[0]
     ...     c1 = self.conns[1]
     ...     if c0.m.is_var:
-    ...         ude.jacobian[c0.m.J_col] = 1
+    ...         self.jacobian[c0.m.J_col] = 1
     ...     if c1.m.is_var:
     ...         self.jacobian[c1.m.J_col] = -2 * self.conns[1].m.val_SI
 

docs/whats_new.rst

@@ -3,6 +3,7 @@ What's New
 
 Discover noteable new features and improvements in each release
 
+.. include::  whats_new/v0-7-2.rst
 .. include::  whats_new/v0-7-1.rst
 .. include::  whats_new/v0-7-0.rst
 .. include::  whats_new/v0-6-3.rst

docs/whats_new/v0-7-2.rst

@@ -0,0 +1,18 @@
+v0.7.1 - Newton's Nature (January, 21, 2024)
+++++++++++++++++++++++++++++++++++++++++++++
+
+Bug Fixes
+#########
+- The `delta` value of the :py:class:`tespy.connections.connection.Ref` class
+  was oriented with the wrong sign. A positive delta lead to a negative value.
+  Fixed in (`PR #459 <https://github.com/oemof/tespy/pull/459>`__).
+- In initial simulations the temperature value of mixtures is 0 by default.
+  For calculating temperatures of the mixtures during that initial simulation,
+  that value was used as starting value causing CoolProp to raise an error and
+  the calculation to crash. This is now prevented by checking if the starting
+  value is reasonable or not
+  (`PR #477 <https://github.com/oemof/tespy/pull/477>`__).
+
+Contributors
+############
+- Francesco Witte (`@fwitte <https://github.com/fwitte>`__)

pyproject.toml

@@ -25,7 +25,7 @@ exclude = ["docs/_build"]
 
 [project]
 name = "tespy"
-version = "0.7.1.post1"
+version = "0.7.2"
 description = "Thermal Engineering Systems in Python (TESPy)"
 readme = "README.rst"
 authors = [
@@ -47,7 +47,7 @@ classifiers = [
 ]
 requires-python = ">=3.9"
 dependencies = [
-    "CoolProp>=6.4,<7",
+    "CoolProp>=6.6,<7",
     "jinja2",
     "matplotlib>=3.2.1,<4",
     "numpy>=1.13.3,<2",

src/tespy/__init__.py

@@ -3,7 +3,7 @@
 import os
 
 __datapath__ = os.path.join(importlib.resources.files("tespy"), "data")
-__version__ = '0.7.1.post1 - Newton\'s Nature'
+__version__ = '0.7.2 - Newton\'s Nature'
 
 # tespy data and connections import
 from . import connections  # noqa: F401

src/tespy/components/combustion/engine.py

@@ -1302,11 +1302,9 @@ def calc_parameters(self):
                 self.outl[i].h.val_SI - self.inl[i].h.val_SI)
             self.get_attr('pr' + str(i + 1)).val = (
                 self.outl[i].p.val_SI / self.inl[i].p.val_SI)
-            self.get_attr('zeta' + str(i + 1)).val = (
-                (self.inl[i].p.val_SI - self.outl[i].p.val_SI) * np.pi ** 2 / (
-                    4 * self.inl[i].m.val_SI ** 2 *
-                    (self.inl[i].vol.val_SI + self.outl[i].vol.val_SI)
-                ))
+            self.get_attr('zeta' + str(i + 1)).val = self.calc_zeta(
+                self.inl[i], self.outl[i]
+            )
 
         self.P.val = self.calc_P()
         self.Qloss.val = self.calc_Qloss()

src/tespy/components/component.py

@@ -12,8 +12,6 @@
 SPDX-License-Identifier: MIT
 """
 
-from collections import OrderedDict
-
 import numpy as np
 
 from tespy.tools import logger
@@ -122,7 +120,7 @@ def __init__(self, label, **kwargs):
         self.fkt_group = self.label
 
         # add container for components attributes
-        self.parameters = OrderedDict(self.get_parameters().copy())
+        self.parameters = self.get_parameters().copy()
         self.__dict__.update(self.parameters)
         self.set_attr(**kwargs)
 
@@ -342,7 +340,7 @@ def preprocess(self, num_nw_vars):
         self.num_eq = 0
         self.vars = {}
         self.num_vars = 0
-        self.constraints = OrderedDict(self.get_mandatory_constraints().copy())
+        self.constraints = self.get_mandatory_constraints().copy()
         self.prop_specifications = {}
         self.var_specifications = {}
         self.group_specifications = {}
@@ -415,7 +413,7 @@ def preprocess(self, num_nw_vars):
             if data.is_set and data.func is not None:
                 self.num_eq += data.num_eq
 
-        self.jacobian = OrderedDict()
+        self.jacobian = {}
         self.residual = np.zeros(self.num_eq)
 
         sum_eq = 0
@@ -813,18 +811,18 @@ def check_parameter_bounds(self):
             if isinstance(data, dc_cp):
                 if data.val > data.max_val + ERR :
                     msg = (
-                        'Invalid value for ' + p + ': ' + p + ' = ' +
-                        str(data.val) + ' above maximum value (' +
-                        str(data.max_val) + ') at component ' + self.label +
-                        '.')
+                        f"Invalid value for {p}: {p} = {data.val} above "
+                        f"maximum value ({data.max_val}) at component "
+                        f"{self.label}."
+                    )
                     logger.warning(msg)
 
                 elif data.val < data.min_val - ERR :
                     msg = (
-                        'Invalid value for ' + p + ': ' + p + ' = ' +
-                        str(data.val) + ' below minimum value (' +
-                        str(data.min_val) + ') at component ' + self.label +
-                        '.')
+                        f"Invalid value for {p}: {p} = {data.val} below "
+                        f"minimum value ({data.max_val}) at component "
+                        f"{self.label}."
+                    )
                     logger.warning(msg)
 
             elif isinstance(data, dc_cc) and data.is_set:
@@ -968,7 +966,8 @@ def enthalpy_equality_func_doc(self, label):
             indices = str(indices[0])
         latex = (
             r'0=h_{\mathrm{in,}i}-h_{\mathrm{out,}i}'
-            r'\; \forall i \in [' + indices + r']')
+            r'\; \forall i \in [' + indices + r']'
+        )
         return generate_latex_eq(self, latex, label)
 
     def enthalpy_equality_deriv(self, k):
@@ -1021,8 +1020,7 @@ def pr_func(self, pr='', inconn=0, outconn=0):
                 0 = p_{in} \cdot pr - p_{out}
         """
         pr = self.get_attr(pr)
-        return (self.inl[inconn].p.val_SI * pr.val -
-                self.outl[outconn].p.val_SI)
+        return self.inl[inconn].p.val_SI * pr.val - self.outl[outconn].p.val_SI
 
     def pr_func_doc(self, label, pr='', inconn=0, outconn=0):
         r"""
@@ -1083,6 +1081,15 @@ def pr_deriv(self, increment_filter, k, pr='', inconn=0, outconn=0):
         if pr.is_var:
             self.jacobian[k, self.pr.J_col] = i.p.val_SI
 
+    def calc_zeta(self, i, o):
+        if abs(i.m.val_SI) <= 1e-4:
+            return 0
+        else:
+            return (
+                (i.p.val_SI - o.p.val_SI) * np.pi ** 2
+                / (4 * i.m.val_SI ** 2 * (i.vol.val_SI + o.vol.val_SI))
+            )
+
     def zeta_func(self, zeta='', inconn=0, outconn=0):
         r"""
         Calculate residual value of :math:`\zeta`-function.

src/tespy/components/heat_exchangers/base.py

@@ -381,10 +381,10 @@ def calculate_td_log(self):
         o2 = self.outl[1]
 
         # temperature value manipulation for convergence stability
-        T_i1 = i1.calc_T(T0=i1.T.val_SI)
-        T_i2 = i2.calc_T(T0=i2.T.val_SI)
-        T_o1 = o1.calc_T(T0=o1.T.val_SI)
-        T_o2 = o2.calc_T(T0=o2.T.val_SI)
+        T_i1 = i1.calc_T()
+        T_i2 = i2.calc_T()
+        T_o1 = o1.calc_T()
+        T_o2 = o2.calc_T()
 
         if T_i1 <= T_o2:
             T_i1 = T_o2 + 0.01
@@ -581,8 +581,8 @@ def ttd_u_func(self):
         """
         i = self.inl[0]
         o = self.outl[1]
-        T_i1 = i.calc_T(T0=i.T.val_SI)
-        T_o2 = o.calc_T(T0=o.T.val_SI)
+        T_i1 = i.calc_T()
+        T_o2 = o.calc_T()
         return self.ttd_u.val - T_i1 + T_o2
 
     def ttd_u_func_doc(self, label):
@@ -636,8 +636,8 @@ def ttd_l_func(self):
         """
         i = self.inl[1]
         o = self.outl[0]
-        T_i2 = i.calc_T(T0=i.T.val_SI)
-        T_o1 = o.calc_T(T0=o.T.val_SI)
+        T_i2 = i.calc_T()
+        T_o1 = o.calc_T()
         return self.ttd_l.val - T_o1 + T_i2
 
     def ttd_l_func_doc(self, label):
@@ -830,20 +830,20 @@ def calc_parameters(self):
         for i in range(2):
             self.get_attr('pr' + str(i + 1)).val = (
                 self.outl[i].p.val_SI / self.inl[i].p.val_SI)
-            self.get_attr('zeta' + str(i + 1)).val = (
-                (self.inl[i].p.val_SI - self.outl[i].p.val_SI) * np.pi ** 2 / (
-                    4 * self.inl[i].m.val_SI ** 2 *
-                    (self.inl[i].vol.val_SI + self.outl[i].vol.val_SI)
-                ))
+            self.get_attr('zeta' + str(i + 1)).val = self.calc_zeta(
+                self.inl[i], self.outl[i]
+            )
 
         # kA and logarithmic temperature difference
         if self.ttd_u.val < 0 or self.ttd_l.val < 0:
             self.td_log.val = np.nan
         elif self.ttd_l.val == self.ttd_u.val:
             self.td_log.val = self.ttd_l.val
         else:
-            self.td_log.val = ((self.ttd_l.val - self.ttd_u.val) /
-                               np.log(self.ttd_l.val / self.ttd_u.val))
+            self.td_log.val = (
+                (self.ttd_l.val - self.ttd_u.val)
+                / np.log(self.ttd_l.val / self.ttd_u.val)
+            )
         self.kA.val = -self.Q.val / self.td_log.val
 
     def entropy_balance(self):

src/tespy/components/heat_exchangers/condenser.py

@@ -19,8 +19,6 @@
 from tespy.tools.data_containers import GroupedComponentCharacteristics as dc_gcc
 from tespy.tools.data_containers import SimpleDataContainer as dc_simple
 from tespy.tools.document_models import generate_latex_eq
-from tespy.tools.fluid_properties import T_mix_ph
-from tespy.tools.fluid_properties import T_sat_p
 from tespy.tools.fluid_properties import dh_mix_dpQ
 from tespy.tools.fluid_properties import h_mix_pQ
 
@@ -329,9 +327,9 @@ def calculate_td_log(self):
         o2 = self.outl[1]
 
         T_i1 = i1.calc_T_sat()
-        T_i2 = i2.calc_T(T0=i2.T.val_SI)
-        T_o1 = o1.calc_T(T0=o1.T.val_SI)
-        T_o2 = o2.calc_T(T0=o2.T.val_SI)
+        T_i2 = i2.calc_T()
+        T_o1 = o1.calc_T()
+        T_o2 = o2.calc_T()
 
         if T_i1 <= T_o2 and not i1.T.is_set:
             T_i1 = T_o2 + 0.5
@@ -454,7 +452,7 @@ def ttd_u_func(self):
         i = self.inl[0]
         o = self.outl[1]
         T_i1 = i.calc_T_sat()
-        T_o2 = o.calc_T(T0=self.outl[1].T.val_SI)
+        T_o2 = o.calc_T()
         return self.ttd_u.val - T_i1 + T_o2
 
     def ttd_u_func_doc(self, label):

src/tespy/components/heat_exchangers/parabolic_trough.py

@@ -274,7 +274,7 @@ def energy_group_func(self):
         i = self.inl[0]
         o = self.outl[0]
 
-        T_m = 0.5 * (i.calc_T(T0=i.T.val_SI) + o.calc_T(T0=o.T.val_SI))
+        T_m = 0.5 * (i.calc_T() + o.calc_T())
 
         iam = (
             1 - self.iam_1.val * abs(self.aoi.val)
@@ -361,10 +361,8 @@ def calc_parameters(self):
 
         self.Q.val = i.m.val_SI * (o.h.val_SI - i.h.val_SI)
         self.pr.val = o.p.val_SI / i.p.val_SI
-        self.zeta.val = (
-            (i.p.val_SI - o.p.val_SI) * np.pi ** 2
-            / (4 * i.m.val_SI ** 2 * (i.vol.val_SI + o.vol.val_SI))
-        )
+        self.zeta.val = self.calc_zeta(i, o)
+
         if self.energy_group.is_set:
             self.Q_loss.val = - self.E.val * self.A.val + self.Q.val
             self.Q_loss.is_result = True