modelExergyMeters
Extends from Modelica.Icons.Example.
Information
Overview
This model shows the usage of all three ExergyMeters, namely
- enthalpy flow: AixLib.Utilities.Sensors.ExergyMeter.FlowExergyMeter
- heat flow: AixLib.Utilities.Sensors.ExergyMeter.HeatExergyMeter
- stored energy: AixLib.Utilities.Sensors.ExergyMeter.StoredExergyMeter
The system is a simplified energy supply system. The supplied heat flow rate matches the extracted heat flow rate. Due to the irreversibilities, especially in the storage, the exergy output is smaller than the exergy input.
Two different exergy balances can be compared. One is calculated using the enthalpy flows. The other is calculated using the heat flow rates. Due to the different system boundaries, the exergy destructions is a little different, as the following figure shows.
- by Marc Baranski and Roozbeh Sangi:
implemented
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Temperature | T_start | 323.15 | Start reference temperature of medium |
| Integer | n | 10 | Number of layers |
| Modelica.Units.SI.Mass | mass | 1000 | Mass of one layer |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Sources.Sine | pulse | Sine wave to vary heat generation and demand | |
| AixLib.Utilities.Sensors.ExergyMeter.StoredExergyMeter | exergyStorageMeterMedium | Outputs the exergy content and rate of change of the considered storage | |
| Modelica.Blocks.Sources.Constant | T_ref | Reference temperature | |
| Modelica.Blocks.Sources.Constant | p_ref | Reference pressure | |
| Modelica.Blocks.Sources.Constant[1] | X_ref | Reference composition | |
| Modelica.Fluid.System | system | Basic parameters | |
| AixLib.Utilities.Sensors.ExergyMeter.HeatExergyMeter | exHeatSec | Exergy content of the heat flux on secondary side | |
| AixLib.Fluid.Movers.FlowControlled_m_flow | pumpPrim | ||
| AixLib.Fluid.Storage.StorageDetailed | bufferStorageHeatingcoils | Storage tank | |
| AixLib.Fluid.FixedResistances.PressureDrop | pipePrim | Main resistance in primary circuit | |
| AixLib.Utilities.Sensors.ExergyMeter.FlowExergyMeter | exPrimIn | Exergy content of medium flow entering the storage on primary side | |
| AixLib.Utilities.Sensors.ExergyMeter.FlowExergyMeter | exPrimOut | Exergy content of medium flow exiting the storage on primary side | |
| Modelica.Fluid.Vessels.ClosedVolume | heater | Volume to heat up the medium | |
| AixLib.Fluid.Movers.FlowControlled_m_flow | pumpSec | Pump in secondary circuit | |
| AixLib.Fluid.FixedResistances.PressureDrop | pipeSec | Main resistance in secondary circuit | |
| Modelica.Fluid.Vessels.ClosedVolume | consumer | Volume to cool down the medium | |
| AixLib.Utilities.Sensors.ExergyMeter.FlowExergyMeter | exSecOut | Exergy content of medium flow entering the storage on secondary side | |
| AixLib.Utilities.Sensors.ExergyMeter.FlowExergyMeter | exSecIn | Exergy content of medium flow exiting the storage on secondary side | |
| Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow | consumerHeatFlow | ||
| Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow | heaterHeatFlow | ||
| Modelica.Blocks.Math.Gain | gain | Negative sign to switch the direction of the heat flux | |
| AixLib.Utilities.Sensors.ExergyMeter.HeatExergyMeter | exHeatPrim | Exergy content of the heat flux on primary side | |
| Modelica.Blocks.Sources.RealExpression[n] | storageTemperatures | Outputs the temperatures of the single storage layers | |
| Modelica.Blocks.Sources.Constant | pumpMassFlow | ||
| AixLib.Fluid.Sources.Boundary_pT | expansionVesselSec | Expansion vessel in secondary circuit | |
| AixLib.Fluid.Sources.Boundary_pT | expansionVesselPrim | Expansion vessel in primary circuit | |
| Modelica.Blocks.Math.Sum | calcExergyDestructionLoss_1 | Calculate the sum of exergy destruction and loss, calculated from enthalpy flows | |
| Modelica.Blocks.Math.Sum | calcExergyDestructionLoss_2 | Calculate the sum of exergy destruction and loss, calculated from heat flows | |
| Modelica.Blocks.Math.Gain | gain1 | Negative sign to switch the direction of the exergy flow | |
| AixLib.Utilities.Sensors.ExergyMeter.StoredExergyMeter | exergyStorageMeterConsumer | Outputs the exergy content and rate of change of the consumer volume | |
| AixLib.Utilities.Sensors.ExergyMeter.StoredExergyMeter | exergyStorageMeterHeater | Outputs the exergy content and rate of change of the heater volume | |
| Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor | heaterTemperature | Measure the temperature in the heater volume | |
| Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor | consumerTemperature | Measure the temperature in the consumer volume |
Contents
| Name | Description |
|---|---|
| Medium | Medium in the sensor |