modelVarTSupplyDpFixedTempDifferenceBypass
Substation with variable supply temperature and fixed dT
Extends from AixLib.Fluid.Interfaces.PartialTwoPortInterface.
Information
A simple substation model using a fixed temperature difference and the actual supply temperature to calculate the mass flow rate drawn from the network. This model uses an open loop design to prescribe the required flow rate.
- Novemver 22, 2019, by Nils Neuland:
Revised variable names and documentation to follow guidelines. - October 23, 2018, by Tobias Blacha:
First implementation.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.HeatFlowRate | Q_flow_nominal | Nominal heat flow rate added to medium | |
| Modelica.Units.SI.TemperatureDifference | dTDesign | Constant temperature difference for the substation's heat exchanger | |
| Modelica.Units.SI.MassFlowRate | m_flo_bypass | Minimum bypass flow through substation | |
| Design parameter | |||
| Modelica.Units.SI.Pressure | dp_nominal | 30000 | Pressure difference at nominal flow rate |
| Flow resistance | |||
| Real | deltaM | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Dynamics | |||
| Modelica.Units.SI.Time | tau | 30 | Time constant at nominal flow (if energyDynamics <> SteadyState) |
| Modelica.Fluid.Types.Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamics.SteadyState | Type of energy balance: dynamic (3 initialization options) or steady state |
| Modelica.Fluid.Types.Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealInput | Q_flow_input | Prescribed heat flow | |
| Sensors.TemperatureTwoPort | senT_supply | Supply flow temperature sensor | |
| Sensors.TemperatureTwoPort | senT_return | Return flow temperature sensor | |
| Modelica.Blocks.Math.Gain | gain | ||
| Modelica.Blocks.Math.Division | hea2MasFlo | ||
| Sources.MassFlowSource_T | sink | Sink extracting prescribed flow from the network | |
| Modelica.Blocks.Math.Gain | changeSign | Changes sign of prescribed flow for extraction from network | |
| Sources.MassFlowSource_T | source | Source sending prescribed flow back to the network | |
| Modelica.Blocks.Interfaces.RealOutput | dpOut | Output signal of pressure difference | |
| Modelica.Blocks.Sources.Constant | deltaT | Fixed temperature difference between supply and return | |
| Modelica.Blocks.Math.Add | temRet | ||
| Utilities.Math.SmoothMax | smoothMax | ||
| Modelica.Blocks.Sources.RealExpression | m_flo_min | ||
| Utilities.Logical.SmoothSwitch | switch1 | ||
| Modelica.Blocks.Logical.LessEqualThreshold | lessEqualThreshold | ||
| MixingVolumes.MixingVolume | vol |