Merge pull request #355 from wouterpeere/update_hydraulic_separatus

Update hydraulic model separatus

Author: wouterpeere

CHANGELOG.md

@@ -21,6 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Remove ghe_logger since no longer used.
 - Make Re a property in borefield just like Rb.
 - Calculate Re and Rb at minimum temperature or, if there is no temperature, the Tf_min.
+- Hydraulic calculations of Separatus.
 
 ### Fixed
 

GHEtool/VariableClasses/PipeData/Separatus.py

@@ -1,6 +1,9 @@
 import pygfunction as gt
+from math import pi
 
 from GHEtool.VariableClasses.PipeData.SingleUTube import SingleUTube
+from GHEtool.VariableClasses.FluidData import _FluidData
+from GHEtool.VariableClasses.FlowData import _FlowData
 
 
 class Separatus(SingleUTube):
@@ -58,6 +61,61 @@ def pipe_model(self, k_s: float, borehole: gt.boreholes.Borehole) -> gt.pipes._B
 
         return single_u
 
+    def Re(self, fluid_data: _FluidData, flow_rate_data: _FlowData, **kwargs) -> float:
+        """
+        Reynolds number.
+        This model uses the hydraulic diameter of 25.51 mm.
+
+        Parameters
+        ----------
+        fluid_data: FluidData
+            Fluid data
+        flow_rate_data : FlowData
+            Flow rate data
+
+        Returns
+        -------
+        Reynolds number : float
+        """
+        u = flow_rate_data.mfr(fluid_data=fluid_data, **kwargs) / fluid_data.rho(**kwargs) / \
+            (pi * (0.02551 / 2) ** 2)
+        return fluid_data.rho(**kwargs) * u * 0.02551 / fluid_data.mu(**kwargs)
+
+    def pressure_drop(self, fluid_data: _FluidData, flow_rate_data: _FlowData, borehole_length: float,
+                      **kwargs) -> float:
+        """
+        Calculates the pressure drop across the entire borehole.
+        This model uses the hydraulic diameter of 25.51 mm.
+
+        Parameters
+        ----------
+        fluid_data: FluidData
+            Fluid data
+        flow_rate_data : FlowData
+            Flow rate data
+        borehole_length : float
+            Borehole length [m]
+
+        Returns
+        -------
+        Pressure drop : float
+            Pressure drop [kPa]
+        """
+
+        # Darcy fluid factor
+        fd = gt.pipes.fluid_friction_factor_circular_pipe(
+            flow_rate_data.mfr(fluid_data=fluid_data, **kwargs),
+            (0.02551 / 2),
+            fluid_data.mu(**kwargs),
+            fluid_data.rho(**kwargs),
+            self.epsilon)
+        A = pi * (0.02551 / 2) ** 2
+        V = (flow_rate_data.vfr(fluid_data=fluid_data, **kwargs) / 1000) / A
+
+        # add 0.2 for the local losses
+        # (source: https://www.engineeringtoolbox.com/minor-loss-coefficients-pipes-d_626.html)
+        return ((fd * (borehole_length * 2) / (0.02551) + 0.2) * fluid_data.rho(**kwargs) * V ** 2 / 2) / 1000
+
     def __export__(self):
         return {'type': 'Separatus',
                 'k_g [W/(m·K)]': self.k_g}

GHEtool/test/unit-tests/test_pipedata.py

@@ -212,6 +212,8 @@ def test_reynolds_number():
     assert np.isclose(double.Re(fluid_data=fluid_data, flow_rate_data=flow_data), 4244.131815783876)
     coaxial = CoaxialPipe(r_in_in, r_in_out, r_out_in, r_out_out, k_p, k_g, is_inner_inlet=True)
     assert np.isclose(coaxial.Re(fluid_data=fluid_data, flow_rate_data=flow_data), 1727.5977540504243)
+    assert np.isclose(SingleUTube(1.5, 0.02551 / 2, 0.03151 / 2, 0.4, 0.035).Re(fluid_data, flow_data),
+                      Separatus(1.5).Re(fluid_data, flow_data))
 
 
 def test_pressure_drop():
@@ -223,6 +225,8 @@ def test_pressure_drop():
     assert np.isclose(double.pressure_drop(fluid_data, flow_data, 100), 10.347836812519452)
     coaxial = CoaxialPipe(r_in_in, r_in_out, r_out_in, r_out_out, k_p, k_g, is_inner_inlet=True)
     assert np.isclose(coaxial.pressure_drop(fluid_data, flow_data, 100), 0.1639237572210245)
+    assert np.isclose(SingleUTube(1.5, 0.02551 / 2, 0.03151 / 2, 0.4, 0.035).pressure_drop(fluid_data, flow_data, 100),
+                      Separatus(1.5).pressure_drop(fluid_data, flow_data, 100))
 
 
 def test_repr_():

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = GHEtool
-version = 2.3.3.dev2
+version = 2.3.3.dev3
 author = Wouter Peere
 author_email = wouter@ghetool.eu
 description = Python package for borefield sizing