Heat buffer efficiency

CHANGELOG.md

@@ -5,6 +5,8 @@
 - Maximum profile constraint for PV asset is considered in PV sizing
 - Cater for input via esdl constraints to specify the upper limit for OPTIONAL assets in DTK
 - Initial implementation of adaptable pipe DN lower limit per pipe
+- DischargeEfficiency is parsed from HeatStorage assets in ESDL to a heat loss coefficient
+
 
 ## Changed
 - Speed-up timeseries check in from InfluxDB

src/mesido/esdl/esdl_heat_model.py

@@ -551,12 +551,20 @@ def convert_heat_buffer(self, asset: Asset) -> Tuple[Type[HeatBuffer], MODIFIERS
             else 10.0e6
         )
 
+        # The asset attribute "dischargeEfficiency" represents the fraction of stored heat
+        # that is lost per day.
+        heat_loss_coefficient = (
+            asset.attributes.get("dischargeEfficiency") / (24.0 * 3600.0)
+            if asset.attributes.get("dischargeEfficiency")
+            else 0.01 / (24.0 * 3600.0)
+        )
+
         q_nominal = self._get_connected_q_nominal(asset)
 
         modifiers = dict(
             height=r,
             radius=r,
-            heat_transfer_coeff=1.0,
+            heat_loss_coefficient=heat_loss_coefficient,
             min_fraction_tank_volume=min_fraction_tank_volume,
             Stored_heat=dict(min=min_heat, max=max_heat),
             Heat_buffer=dict(min=-hfr_discharge_max, max=hfr_charge_max),

src/mesido/pycml/component_library/milp/heat/heat_buffer.py

@@ -32,11 +32,15 @@ def __init__(self, name, **modifiers):
 
         self.component_type = "heat_buffer"
 
-        self.heat_transfer_coeff = 1.0
         self.height = 5.0
         self.radius = 10.0
         self.volume = math.pi * self.radius**2 * self.height
-        self.heat_loss_coeff = 2 * self.heat_transfer_coeff / (self.radius * self.rho * self.cp)
+        self.heat_loss_coefficient = nan
+        # self.heat_transfer_coeff = 1.0
+        # self.heat_loss_coefficient = (
+        #     2 * self.heat_transfer_coeff / (self.radius * self.rho * self.cp)
+        # )
+
         # The hot/cold tank can have a lower bound on its volume.
         # Meaning that they might always be, for e.g., 5% full.
         self.min_fraction_tank_volume = 0.05
@@ -78,7 +82,9 @@ def __init__(self, name, **modifiers):
         # 10.0, we aim for a state vector entry of ~0.1 (instead of 1.0)
         self._heat_loss_error_to_state_factor = 10.0
         self._nominal_heat_loss = (
-            self._nominal_stored_heat * self.heat_loss_coeff * self._heat_loss_error_to_state_factor
+            self._nominal_stored_heat
+            * self.heat_loss_coefficient
+            * self._heat_loss_error_to_state_factor
         )
 
         self.add_variable(Variable, "Heat_loss", min=0.0, nominal=self._nominal_heat_loss)
@@ -91,7 +97,8 @@ def __init__(self, name, **modifiers):
             / self._heat_loss_eq_nominal_buf
         )
         self.add_equation(
-            (self.Heat_loss - self.Stored_heat * self.heat_loss_coeff) / self._nominal_heat_loss
+            (self.Heat_loss - self.Stored_heat * self.heat_loss_coefficient)
+            / self._nominal_heat_loss
         )
 
         self.add_equation((self.Heat_flow - self.Heat_buffer) / self.Heat_nominal)

tests/models/test_case_small_network_with_ates_buffer_geo/model/test_case_small_network_with_ates_buffer_geo.esdl

@@ -401,7 +401,7 @@
           </investmentCosts>
         </costInformation>
       </asset>
-      <asset xsi:type="esdl:HeatStorage" name="HeatStorage_74c1" id="74c13eed-9ca8-4247-bd72-a68e242d8e1b" maxDischargeRate="10000000.0" maxChargeRate="10000000.0" volume="500.0">
+      <asset xsi:type="esdl:HeatStorage" name="HeatStorage_74c1" id="74c13eed-9ca8-4247-bd72-a68e242d8e1b" maxDischargeRate="10000000.0" maxChargeRate="10000000.0" volume="500.0" dischargeEfficiency="0.01">
         <geometry xsi:type="esdl:Point" lon="4.313871860504151" CRS="WGS84" lat="52.042658996032856"/>
         <port xsi:type="esdl:InPort" id="8c09b9ff-5070-4fbc-97fe-db7a501932dc" name="In" connectedTo="636a1943-2289-4d57-a2dd-33aaa4f25b49" carrier="7b32e287-d775-480c-b317-64ffdacf12c9"/>
         <port xsi:type="esdl:OutPort" id="cc725203-e648-490f-a12d-91fa85ee58f2" name="Out" connectedTo="a581c340-3cab-46b1-924f-c5ddc0120de6" carrier="7b32e287-d775-480c-b317-64ffdacf12c9_ret"/>