Merge pull request #366 from wouterpeere/conical-pipes

Conical pipes

Author: wouterpeere

CHANGELOG.md

@@ -10,6 +10,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ###
 
 - Added Turbocollector from Muovitech.
+- Add flag in pressure drop calculation to in or exclude the pressure drop in the bend.
+- Added conical borehole heat exchangers (like the GEROtherm VARIO and FLUX probe from HakaGerodur).
 
 ### Fixed
 

GHEtool/Borefield.py

@@ -1950,7 +1950,8 @@ def Re(self) -> float:
             Reynolds number
         """
         return self.borehole.Re(
-            temperature=self.results.min_temperature if self.results.min_temperature is not None else self.Tf_min)
+            temperature=self.results.min_temperature if self.results.min_temperature is not None else self.Tf_min,
+            borehole_length=self.H)  # for conical pipes
 
     def calculate_quadrant(self) -> int:
         """

GHEtool/Examples/Hydratech.py

@@ -0,0 +1,98 @@
+from GHEtool import *
+import matplotlib.pyplot as plt
+import numpy as np
+
+regular_pipe = SingleUTube(1.5, 0.013, 0.016, 0.4, 0.035)
+regular_pipe_PN12 = SingleUTube(1.5, 0.0135, 0.016, 0.4, 0.035)
+vario = ConicalPipe(1.5, 0.0135, 0.013, 80, 160, 0.016, 0.4, 0.035, 1)
+
+fluid = TemperatureDependentFluidData('MEG', 25).create_constant(3)
+flow = ConstantFlowRate(vfr=0.9 / 3.6)
+
+length = np.arange(100, 160, 1)
+
+dp_regular = [regular_pipe.pressure_drop(fluid, flow, i) for i in length]
+dp_regular_pn12 = [regular_pipe_PN12.pressure_drop(fluid, flow, i) for i in length]
+dp_vario = [vario.pressure_drop(fluid, flow, i) for i in length]
+
+reynolds_regular = [regular_pipe.Re(fluid, flow, borehole_length=i) for i in length]
+reynolds_vario = [vario.Re(fluid, flow, borehole_length=i) for i in length]
+
+plt.figure()
+plt.plot(length, dp_vario, label="vario")
+plt.plot(length, dp_regular, label="regular PN16")
+plt.plot(length, dp_regular_pn12, label="regular PN12")
+plt.xlabel('Length [m]')
+plt.ylabel('Pressure drop [kPa]')
+plt.legend()
+
+plt.figure()
+plt.plot(length, reynolds_vario, label="vario")
+plt.plot(length, reynolds_regular, label="regular")
+plt.xlabel('Length [m]')
+plt.ylabel('Reynolds [-]')
+plt.legend()
+
+# borehole resistance
+vfr_range = np.arange(0.05, 0.8, 0.005)
+
+rb_regular = []
+rb_regular_pn12 = []
+rb_vario = []
+r_f_regular = []
+r_p_regular = []
+r_f_regular_pn12 = []
+r_p_regular_pn12 = []
+r_f_vario = []
+r_p_vario = []
+dp_regular = []
+dp_vario = []
+dp_regular_pn12 = []
+
+for vfr in vfr_range:
+    flow = ConstantFlowRate(vfr=vfr)
+    borehole_regular = Borehole(fluid, regular_pipe, flow)
+    borehole_vario = Borehole(fluid, vario, flow)
+    borehole_regular_pn12 = Borehole(fluid, regular_pipe_PN12, flow)
+    rb_regular.append(borehole_regular.get_Rb(150, 1, 0.07, 2))
+    rb_regular_pn12.append(borehole_regular_pn12.get_Rb(150, 1, 0.07, 2))
+
+    rb_vario.append(borehole_vario.get_Rb(150, 1, 0.07, 2))
+    r_f_regular.append(borehole_regular.pipe_data.R_f)
+    r_f_regular_pn12.append(borehole_regular_pn12.pipe_data.R_f)
+    r_p_regular.append(borehole_regular.pipe_data.R_p)
+    r_p_regular_pn12.append(borehole_regular_pn12.pipe_data.R_p)
+    r_f_vario.append(borehole_vario.pipe_data.R_f)
+    r_p_vario.append(borehole_vario.pipe_data.R_p)
+
+    dp_regular.append(regular_pipe.pressure_drop(fluid, flow, borehole_length=160))
+    dp_regular_pn12.append(regular_pipe_PN12.pressure_drop(fluid, flow, borehole_length=160))
+    dp_vario.append(vario.pressure_drop(fluid, flow, borehole_length=160))
+
+plt.figure()
+plt.plot(vfr_range, rb_vario, label="vario")
+plt.plot(vfr_range, rb_regular, label="regular PN 16")
+
+plt.xlabel('Volume flow rate [l/s]')
+plt.ylabel('Effective borehole thermal resistance [W/(mK)]')
+plt.legend()
+
+plt.figure()
+plt.plot(vfr_range, r_p_vario, label="R_p vario")
+plt.plot(vfr_range, r_p_regular, label="R_p regular PN16")
+plt.plot(vfr_range, r_p_regular_pn12, label="R_p regular PN12")
+plt.plot(vfr_range, r_f_vario, label="R_f vario")
+plt.plot(vfr_range, r_f_regular, label="R_f regular PN16")
+plt.plot(vfr_range, r_f_regular_pn12, label="R_f regular PN12")
+plt.xlabel('Volume flow rate [l/s]')
+plt.ylabel('Effective borehole thermal resistance [W/(mK)]')
+plt.legend()
+
+plt.figure()
+plt.plot(vfr_range, dp_vario, label="Vario")
+plt.plot(vfr_range, dp_regular, label="Regular PN16")
+plt.plot(vfr_range, dp_regular_pn12, label="Regular PN12")
+plt.xlabel('Volume flow rate [l/s]')
+plt.ylabel('Pressure drop [kPa]')
+plt.legend()
+plt.show()

GHEtool/Examples/Muovitech_new.py

@@ -296,7 +296,7 @@ def calculate_Rb(self, H: float, D: float, r_b: float, k_s: Union[float, callabl
         borehole = gt.boreholes.Borehole(H, D, r_b, 0, 0)
 
         def calculate(**kwargs):
-            self.pipe_data.calculate_resistances(self.fluid_data, self.flow_data, **kwargs)
+            self.pipe_data.calculate_resistances(self.fluid_data, self.flow_data, borehole_length=H, **kwargs)
 
             # initiate pipe
             pipe = self.pipe_data.pipe_model(k_s if isinstance(k_s, (float, int)) else k_s(depth, D), borehole)

GHEtool/Examples/Vario.py

@@ -147,7 +147,7 @@ def Re(self, fluid_data: _FluidData, flow_rate_data: _FlowData, **kwargs) -> flo
         return fluid_data.rho(**kwargs) * V * D_h / fluid_data.mu(**kwargs)
 
     def pressure_drop(self, fluid_data: _FluidData, flow_rate_data: _FlowData, borehole_length: float,
-                      **kwargs) -> float:
+                      include_bend: bool = True, **kwargs) -> float:
         """
         Calculates the pressure drop across the entire borehole.
         It assumed that the U-tubes are all connected in parallel.
@@ -160,6 +160,8 @@ def pressure_drop(self, fluid_data: _FluidData, flow_rate_data: _FlowData, boreh
             Flow rate data
         borehole_length : float
             Borehole length [m]
+        include_bend : bool
+            True if the losses in the bend should be included
 
         Returns
         -------
@@ -178,9 +180,12 @@ def pressure_drop(self, fluid_data: _FluidData, flow_rate_data: _FlowData, boreh
             flow_rate_data.mfr(fluid_data=fluid_data, **kwargs), r_h, fluid_data.mu(**kwargs), fluid_data.rho(**kwargs),
             self.epsilon)
 
-        # add 0.2 for the local losses
-        # (source: https://www.engineeringtoolbox.com/minor-loss-coefficients-pipes-d_626.html)
-        return ((fd * (borehole_length * 2) / (2 * r_h) + 0.2) * fluid_data.rho(**kwargs) * V ** 2 / 2) / 1000
+        bend = 0
+        if include_bend:
+            # add 0.2 for the local losses
+            # (source: https://www.engineeringtoolbox.com/minor-loss-coefficients-pipes-d_626.html)
+            bend = 0.2
+        return ((fd * (borehole_length * 2) / (2 * r_h) + bend) * fluid_data.rho(**kwargs) * V ** 2 / 2) / 1000
 
     def draw_borehole_internal(self, r_b: float) -> None:
         """