modelVarTSupplyDp
Substation with variable dT for fixed return temperature
Extends from AixLib.Fluid.Interfaces.PartialTwoPortInterface.
Information
A simple substation model using a fixed return temperature 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. - March 4, 2018, by Marcus Fuchs:
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 | Design temperature difference for the substation's heat exchanger | |
| Modelica.Units.SI.Temperature | TReturn | Fixed return temperature | |
| 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.Add | deltaT | Differernce of flow and return line temperature in K | |
| Modelica.Blocks.Sources.Constant | temRet | Temperature of return line in °C | |
| 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 | mindeltaT | Temperature of return line in °C | |
| Modelica.Blocks.Math.Max | max | ||
| Modelica.Blocks.Math.Min | min | ||
| Modelica.Blocks.Sources.Constant | temRet_nominal | Temperature of return line in °C | |
| Modelica.Blocks.Math.Add | deltaT1 | Differernce of flow and return line temperature in K |