Refactor/introduce time series fluid density (#1010)

* refactor: introduce time series fluid density

Author: frodehk

src/libecalc/domain/infrastructure/energy_components/legacy_consumer/consumer_function/pump_consumer_function.py

@@ -11,6 +11,7 @@
 )
 from libecalc.domain.process.pump.pump import PumpModel
 from libecalc.domain.time_series_flow_rate import TimeSeriesFlowRate
+from libecalc.domain.time_series_fluid_density import TimeSeriesFluidDensity
 from libecalc.domain.time_series_pressure import TimeSeriesPressure
 from libecalc.expression import Expression
 
@@ -21,10 +22,10 @@ class PumpConsumerFunction(ConsumerFunction):
 
     Args:
         pump_function: The pump model
+        fluid_density (TimeSeriesFluidDensity): Fluid density time series [kg/m3]
         rate (TimeSeriesFlowRate): Flow rate time series [Sm3/h].
         suction_pressure (TimeSeriesPressure): Suction pressure time series [bara].
         discharge_pressure (TimeSeriesPressure): Discharge pressure time series [bara].
-        fluid_density_expression: Fluid density expression [kg/m3]
         power_loss_factor_expression: Optional power loss factor expression.
             Typically used for power line loss subsea et.c.
     """
@@ -35,14 +36,14 @@ def __init__(
         rate: TimeSeriesFlowRate,
         suction_pressure: TimeSeriesPressure,
         discharge_pressure: TimeSeriesPressure,
-        fluid_density_expression: Expression,
+        fluid_density: TimeSeriesFluidDensity,
         power_loss_factor_expression: Expression = None,
     ):
         self._pump_function = pump_function
         self._rate = rate
+        self._fluid_density = fluid_density
         self._suction_pressure = suction_pressure
         self._discharge_pressure = discharge_pressure
-        self._fluid_density_expression = fluid_density_expression
 
         # Typically used for power line loss subsea et.c.
         self._power_loss_factor_expression = power_loss_factor_expression
@@ -64,14 +65,12 @@ def evaluate(
 
         stream_day_rate = self._rate.get_stream_day_values()
 
-        fluid_density = expression_evaluator.evaluate(expression=self._fluid_density_expression)
-
         # Do not input regularity to pump function. Handled outside
         energy_function_result = self._pump_function.evaluate_rate_ps_pd_density(
             rate=np.asarray(stream_day_rate, dtype=np.float64),
             suction_pressures=np.asarray(self._suction_pressure.get_values(), dtype=np.float64),
             discharge_pressures=np.asarray(self._discharge_pressure.get_values(), dtype=np.float64),
-            fluid_density=np.asarray(fluid_density, dtype=np.float64),
+            fluid_density=np.asarray(self._fluid_density.get_values(), dtype=np.float64),
         )
 
         power_loss_factor = get_power_loss_factor_from_expression(

src/libecalc/domain/time_series_fluid_density.py

@@ -0,0 +1,16 @@
+from abc import ABC, abstractmethod
+from collections.abc import Sequence
+
+
+class TimeSeriesFluidDensity(ABC):
+    """
+    Interface for evaluating fluid density time series.
+
+    """
+
+    @abstractmethod
+    def get_values(self) -> Sequence[float]:
+        """
+        Returns the evaluated fluid density values as a NumPy array.
+        """
+        pass

src/libecalc/presentation/yaml/domain/expression_time_series_fluid_density.py

@@ -0,0 +1,22 @@
+from collections.abc import Sequence
+
+from libecalc.domain.time_series_fluid_density import TimeSeriesFluidDensity
+from libecalc.presentation.yaml.domain.time_series_expression import TimeSeriesExpression
+
+
+class ExpressionTimeSeriesFluidDensity(TimeSeriesFluidDensity):
+    """
+    Provides fluid density values by evaluating a time series expression.
+    """
+
+    def __init__(self, time_series_expression: TimeSeriesExpression):
+        self._time_series_expression = time_series_expression
+
+    def get_values(self) -> Sequence[float]:
+        """
+        Returns the fluid density values as a NumPy array.
+        """
+
+        fluid_density_values = self._time_series_expression.get_evaluated_expressions()
+
+        return fluid_density_values

src/libecalc/presentation/yaml/mappers/consumer_function_mapper.py

@@ -46,6 +46,7 @@
 from libecalc.dto.utils.validators import convert_expression, convert_expressions
 from libecalc.expression import Expression
 from libecalc.presentation.yaml.domain.expression_time_series_flow_rate import ExpressionTimeSeriesFlowRate
+from libecalc.presentation.yaml.domain.expression_time_series_fluid_density import ExpressionTimeSeriesFluidDensity
 from libecalc.presentation.yaml.domain.expression_time_series_pressure import ExpressionTimeSeriesPressure
 from libecalc.presentation.yaml.domain.reference_service import ReferenceService
 from libecalc.presentation.yaml.domain.time_series_expression import TimeSeriesExpression
@@ -275,6 +276,11 @@ def _map_pump(
             condition_expression=condition,
         )
 
+        fluid_density_expression = TimeSeriesExpression(
+            expressions=model.fluid_density, expression_evaluator=period_evaluator
+        )
+        fluid_density = ExpressionTimeSeriesFluidDensity(time_series_expression=fluid_density_expression)
+
         suction_pressure_expression = TimeSeriesExpression(
             expressions=model.suction_pressure, expression_evaluator=period_evaluator
         )
@@ -285,15 +291,14 @@ def _map_pump(
         )
         discharge_pressure = ExpressionTimeSeriesPressure(time_series_expression=discharge_pressure_expression)
 
-        fluid_density = convert_expression(model.fluid_density)
         pump_model = create_pump_model(pump_model_dto=energy_model)
         return PumpConsumerFunction(
             power_loss_factor_expression=power_loss_factor,  # type: ignore[arg-type]
             pump_function=pump_model,
             rate=rate_standard_m3_day,
             suction_pressure=suction_pressure,
             discharge_pressure=discharge_pressure,
-            fluid_density_expression=fluid_density,  # type: ignore[arg-type]
+            fluid_density=fluid_density,
         )
 
     def _map_multiple_streams_compressor(

tests/libecalc/core/consumers/system/test_consumer_system.py

@@ -28,6 +28,7 @@
 from libecalc.domain.regularity import Regularity
 from libecalc.expression import Expression
 from libecalc.presentation.yaml.domain.expression_time_series_pressure import ExpressionTimeSeriesPressure
+from libecalc.presentation.yaml.domain.expression_time_series_fluid_density import ExpressionTimeSeriesFluidDensity
 from libecalc.presentation.yaml.domain.time_series_expression import TimeSeriesExpression
 from libecalc.presentation.yaml.domain.expression_time_series_flow_rate import ExpressionTimeSeriesFlowRate
 
@@ -373,6 +374,9 @@ def test_pump_consumer_function_and_pump_system_consumer_function(self, expressi
         rate_expression = TimeSeriesExpression(expressions=6648.0, expression_evaluator=variables_map)
         rate = ExpressionTimeSeriesFlowRate(time_series_expression=rate_expression, regularity=regularity)
 
+        fluid_density_expression = TimeSeriesExpression(expressions=1021.0, expression_evaluator=variables_map)
+        fluid_density = ExpressionTimeSeriesFluidDensity(time_series_expression=fluid_density_expression)
+
         suction_pressure_expression = TimeSeriesExpression(expressions=1.0, expression_evaluator=variables_map)
         suction_pressure = ExpressionTimeSeriesPressure(time_series_expression=suction_pressure_expression)
 
@@ -382,17 +386,17 @@ def test_pump_consumer_function_and_pump_system_consumer_function(self, expressi
         pump_consumer_function = PumpConsumerFunction(
             pump_function=pump,
             rate=rate,
+            fluid_density=fluid_density,
             suction_pressure=suction_pressure,
             discharge_pressure=discharge_pressure,
-            fluid_density_expression=Expression.setup_from_expression(1021),
         )
         power_loss_factor = 0.03
         pump_consumer_function_with_power_loss_factor = PumpConsumerFunction(
             pump_function=pump,
             rate=rate,
+            fluid_density=fluid_density,
             suction_pressure=suction_pressure,
             discharge_pressure=discharge_pressure,
-            fluid_density_expression=Expression.setup_from_expression(1021),
             power_loss_factor_expression=Expression.setup_from_expression(str(power_loss_factor)),
         )