modelConsumer_LowTemperatureDHN
Information
Purpose of model
A model of a low temperature district heating network consumer. It contains a P-Controller, a pump, a heat exchanger, a thermal capacity and a heat conductance. The heat exchanger contains an integrated heat pump to increase the temperature of the heat source. The P-Controller sets the mass flow rate through the pump so that the temperature of the thermal capacity is kept constant. The thermal capacity represents the thermal capacity of the building. Heat losses are calculated with the thermal resistance and the temperature difference between the thermal capacity and the ambient temperature. The ambient temperature is set with a RealInput.
The difference to the consumer and Consumer_SLP model is that the supply and the return temperature of the building are calculated from the heat characteristics of the building.
The difference to the ConsumerHeatCharacteristic model is that the heat exchanger model has an integrated heat pump.
The model ist based on TransiEnt.Consumer.Heat.ConsumerHeatCharacteristic.
Level of detail, physical effects considered, and physical insight
- P-controler
- heat losses from the building to the environemnt
- a thermal capacity of the buildings
References
Version History
Model was inserted by Jan Westphal (j.westphal@tuhh.de) August 2025
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | multiplicationFactor | 1 | Factor for the heat flow rate multiplication (for upscaling of consumer) |
| Real | G | 155.737 | Thermal Conuctivity of the thermal resistor |
| SI.HeatCapacity | C | 570000 | Thermal capacity of the heat capacitor |
| SI.PressureDifference | delta_p_nom | 0.1e5 | Nominal pressure difference of the valve inside the consumer |
| SI.MassFlowRate | m_flow_nom | 0.18 | Nominal mass flow rate of the water (used in the valve) |
| SI.HeatFlowRate | Q_flow_nom | 8e3 | Nominal heat flow rate (used in the heat exchanger) |
| SI.Temperature | T_room | 295.15 | Set value for room temperature |
| SI.Time | tau_i | 1000 | Constant for integrator part of PI-controller |
| Real | k | 20 | Constant for proportional part of PI-controller |
| Real | y_max | 3*m_flow_nom | Max. opening of valve |
| Real | y_min | 0.0001 | Min. opening of valve |
| Real | cp | 4186 | |
| String | DHWfileName | "Data_files/dhw_demand_w_dym.txt" | |
| String | DHWtableName | "tab1" |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.Basics.Interfaces.Thermal.FluidPortIn_simple | inlet | ||
| TransiEnt.Basics.Interfaces.Thermal.FluidPortOut_simple | outlet | ||
| Modelica.Blocks.Interfaces.RealInput | T_outdoor_K |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.HeatFlowRate | Q_flow_C | ||
| Modelica.Thermal.HeatTransfer.Components.HeatCapacitor | heatCapacitor1 | ||
| Modelica.Thermal.HeatTransfer.Components.ThermalConductor | thermalConductor1 | ||
| TransiEnt.Components.Heat.HeatFlowMultiplier | heatFlowMultiplier | ||
| Modelica.Thermal.HeatTransfer.Sources.PrescribedTemperature | AmbientTemperature1 | ||
| TransiEnt.Components.Heat.SimplePump_mflow | pump | ||
| Modelica.Blocks.Sources.RealExpression | SetTemperature | ||
| Modelica.Thermal.HeatTransfer.Celsius.TemperatureSensor | temperatureSensor1 | ||
| TransiEnt.Producer.Heat.Power2Heat.Heatpump.HeatPump_LowTemperatureDHN | heatPump | ||
| Modelica.Blocks.Continuous.LimPID | PID1 | ||
| TransiEnt.Consumer.Heat.HeatCharacteristicDoublePort | heatCharacteristicsDoublePort |