Merge pull request #404 from wouterpeere/issue403-get_rb-is-slow-for-variable-fluid-properties

Issue403 get rb is slow for variable fluid properties

Author: wouterpeere

CHANGELOG.md

@@ -18,6 +18,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix problem with start month in optimise for power/balance (issue #380).
 - Return multiyear external load if multiyear load is given as an input (issue #380).
 - Change how DHW is stored in the classes (issue #381).
+- Speed up calculate required depth (issue #403).
 
 ### Fixed
 

GHEtool/Borefield.py

@@ -40,6 +40,8 @@ class Borefield(BaseClass):
     DEFAULT_LENGTH_PEAK: int = 6  # hours
     THRESHOLD_DEPTH_ERROR: int = 10000  # m
 
+    USE_SPEED_UP_IN_SIZING: bool = True
+
     HOURLY_LOAD_ARRAY: np.ndarray = np.arange(0, 8761, UPM).astype(np.uint32)
 
     def __init__(
@@ -1338,6 +1340,10 @@ def size_L3(self, H_init: float = None, quadrant_sizing: int = 0) -> float:
         if quadrant_sizing != 0:
             # size according to a specific quadrant
             self.H, _ = self._size_based_on_temperature_profile(quadrant_sizing)
+
+            # simulate with the correct temperatures
+            self.calculate_temperatures()
+
             return self.H
         else:
             try:
@@ -1352,6 +1358,10 @@ def size_L3(self, H_init: float = None, quadrant_sizing: int = 0) -> float:
             if sized:
                 # already correct size
                 self.H = max_temp
+
+                # simulate with the correct temperatures
+                self.calculate_temperatures()
+
                 if self.load.imbalance <= 0:
                     self.limiting_quadrant = 1
                 else:
@@ -1360,6 +1370,10 @@ def size_L3(self, H_init: float = None, quadrant_sizing: int = 0) -> float:
             min_temp, sized = self._size_based_on_temperature_profile(20)
             if sized:
                 self.H = min_temp
+
+                # simulate with the correct temperatures
+                self.calculate_temperatures()
+
                 if self.load.imbalance <= 0:
                     self.limiting_quadrant = 4
                 else:
@@ -1407,6 +1421,10 @@ def size_L4(self, H_init: float = None, quadrant_sizing: int = 0) -> float:
         if quadrant_sizing != 0:
             # size according to a specific quadrant
             self.H, _ = self._size_based_on_temperature_profile(quadrant_sizing, hourly=True)
+
+            # simulate with the correct temperatures
+            self.calculate_temperatures(hourly=True)
+
             return self.H
         else:
             try:
@@ -1428,6 +1446,10 @@ def size_L4(self, H_init: float = None, quadrant_sizing: int = 0) -> float:
             if sized:
                 # already correct size
                 self.H = max_temp
+
+                # simulate with the correct temperatures
+                self.calculate_temperatures(hourly=True)
+
                 if self.load.imbalance <= 0:
                     self.limiting_quadrant = 1
                 else:
@@ -1441,6 +1463,10 @@ def size_L4(self, H_init: float = None, quadrant_sizing: int = 0) -> float:
                 else:
                     self.limiting_quadrant = 3
                 self.H = min_temp
+
+                # simulate with the correct temperatures
+                self.calculate_temperatures(hourly=True)
+
                 return min_temp
             raise UnsolvableDueToTemperatureGradient
 
@@ -1450,7 +1476,7 @@ def calculate_next_depth_deep_sizing(self, current_length: float) -> float:
         borefield is sized for the maximum fluid temperature when there is a non-constant ground temperature.
         The method is based (as can be seen in its corresponding validation document) on the assumption that the
         difference between the maximum temperature in peak injection and the average undisturbed ground temperature
-        is irreversily proportional to the borehole length. In this way, given this difference in temperature and the current
+        is irreversibly proportional to the borehole length. In this way, given this difference in temperature and the current
         borehole length, a new borehole length can be calculated.
 
         Parameters
@@ -1517,10 +1543,11 @@ def _size_based_on_temperature_profile(self, quadrant: int, hourly: bool = False
         while not self._check_convergence(self.H, H_prev, i):
             if H_prev != 0:
                 self.H = self.H * .5 + H_prev * 0.5
+            limit = self.Tf_min if quadrant in (3, 4, 20) else self.Tf_max
             if hourly:
-                self._calculate_temperature_profile(self.H, hourly=True)
+                self._calculate_temperature_profile(self.H, hourly=True, fluid_temperature=limit)
             else:
-                self._calculate_temperature_profile(self.H, hourly=False)
+                self._calculate_temperature_profile(self.H, hourly=False, fluid_temperature=limit)
             H_prev = self.H
             if not deep_sizing:
                 if quadrant == 1:
@@ -1713,7 +1740,8 @@ def _delete_calculated_temperatures(self) -> None:
         self.results = ResultsMonthly()
         self.load.reset_results(self.Tf_min, self.Tf_max)
 
-    def _calculate_temperature_profile(self, H: float = None, hourly: bool = False) -> None:
+    def _calculate_temperature_profile(self, H: float = None, hourly: bool = False,
+                                       fluid_temperature: float = None) -> None:
         """
         This function calculates the evolution in the fluid temperature and borehole wall temperature.
 
@@ -1723,6 +1751,8 @@ def _calculate_temperature_profile(self, H: float = None, hourly: bool = False)
             Borehole length at which the temperatures should be evaluated [m]. If None, then the current length is taken.
         hourly : bool
             True if the temperature evolution should be calculated on an hourly basis.
+        fluid_temperature : float
+            During sizing, this differs from None so the specific temperature is taken.
 
         Returns
         -------
@@ -1740,12 +1770,13 @@ def calculate_temperatures(H, hourly=hourly, results_temperature=ResultsMonthly(
             results = None
 
             def get_rb(temperature):
+                if fluid_temperature is not None and Borefield.USE_SPEED_UP_IN_SIZING:
+                    return self.borehole.get_Rb(H, self.D, self.r_b, self.ground_data.k_s(depth, self.D), depth,
+                                                temperature=fluid_temperature)
                 if len(temperature) == 0:
-                    return self.borehole.get_Rb(H, self.D, self.r_b,
-                                                self.ground_data.k_s(depth, self.D), depth,
+                    return self.borehole.get_Rb(H, self.D, self.r_b, self.ground_data.k_s(depth, self.D), depth,
                                                 temperature=self.Tf_min)
-                return self.borehole.get_Rb(H, self.D, self.r_b,
-                                            self.ground_data.k_s(depth, self.D), depth,
+                return self.borehole.get_Rb(H, self.D, self.r_b, self.ground_data.k_s(depth, self.D), depth,
                                             temperature=temperature)
 
             if not hourly:

GHEtool/test/general_tests/test_GHEtool.py

@@ -496,4 +496,4 @@ def test_case_issue_390():
 
     borefield.borehole = borehole
     borefield.size_L3()
-    assert borefield.H == 86.4119598683636
+    assert np.isclose(borefield.H, 86.31427258402536)

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = GHEtool
-version = 2.4.0.dev11
+version = 2.4.0.dev12
 author = Wouter Peere
 author_email = wouter@ghetool.eu
 description = Python package for borefield sizing