modelFirstOrderHeatingNetworkConsumer
Extends from PartialHeatConsumer (Partial model of a heat sink).
Information
1. Purpose of model
Model represents a district heating station consumer. The model calculates the mass flow according to the feed water temperature and the prescribed heat flow demand. It reacts to a change in feed water temperature by reducing mass flow in returning mass flow path. There is no mass flow balance active.
2. Level of detail, physical effects considered, and physical insight
(no remarks)
3. Limits of validity
Model makes sense only if it is used in a closed loop, meaning that the mass flow at outlet and inlet is the same by definition. Otherwise mass flow balance is not forfilled!
4. Interfaces
(no remarks)
5. Nomenclature
(no remarks)
6. Governing Equations
(no remarks)
7. Remarks for Usage
(no remarks)
8. Validation
Tested in the check models "TransiEnt.Consumer.Heat.Check.TestFirstOrderHeatingNetworkConsumer" and "TransiEnt.Consumer.Heat.Check.TestFirstOrderHeatingNetworkConsumer_withPlant"
9. References
(no remarks)
10. Version History
Model created by pd (dubucq@tuhh.de) in April 2016.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| TILMedia.VLEFluidTypes.BaseVLEFluid | medium (from PartialHeatConsumer) | simCenter.fluid1 | |
| ClaRa.Basics.Units.Temperature | T_return_const | 293.15 | Return temperature, if use_T_return_const |
| SI.Pressure | p_feed_const | 12e5 | Pressure at consumer station, feed water side |
| SI.Pressure | p_return_const | 10e5 | Pressure at consumer station, return water side |
| SI.MassFlowRate | m_flow_large | 2000 | Limit of mass flow rate |
| SI.MassFlowRate | m_flow_small | simCenter.m_flow_small | Lower limits of input signals |
| SI.Time | T_massflow_ctrl | 0.5 | Time constant of mass flow adaption |
| Real | m_flow_init | 750 | Initial or guess value of output (= state) |
| Boolean | use_T_return_const | true |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.Basics.Interfaces.Thermal.FluidPortOut | fluidPortOut (from PartialHeatConsumer) | ||
| TransiEnt.Basics.Interfaces.Thermal.FluidPortIn | fluidPortIn (from PartialHeatConsumer) | ||
| TransiEnt.Basics.Interfaces.Thermal.HeatFlowRateIn | Q_flow_demand | Total heatflowrate demand | |
| TransiEnt.Basics.Interfaces.General.TemperatureIn | T_return_set | Return temperature set point | |
| TransiEnt.Basics.Interfaces.General.EyeOut | eye |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.ModelStatistics | modelStatistics (from PartialHeatConsumer) | ||
| TransiEnt.SimCenter | simCenter (from PartialHeatConsumer) | ||
| TransiEnt.Components.Sensors.TemperatureSensor | T_in (from PartialHeatConsumer) | ||
| TransiEnt.Components.Sensors.TemperatureSensor | T_out (from PartialHeatConsumer) | ||
| TransiEnt.Components.Statistics.Collectors.LocalCollectors.CollectHeatingPower | collectHeatingPower (from PartialHeatConsumer) | ||
| ClaRa.Components.BoundaryConditions.BoundaryVLE_Txim_flow | source | ||
| ClaRa.Components.BoundaryConditions.BoundaryVLE_pTxi | sink | ||
| Modelica.Blocks.Sources.RealExpression | m_flow_target_set | ||
| SI.MassFlowRate | m_flow_target | Mass flow is determined by heat balance | |
| SI.SpecificHeatCapacity | cp_in | TILMedia.Internals.VLEFluidConfigurations.FullyMixtureCompatible.VLEFluidFunctions.liquidSpecificHeatCapacity_phxi(medium, fluidPortIn.p, inStream(fluidPortIn.h_outflow), inStream(fluidPortIn.xi_outflow)) | |
| SI.Density | rho | TILMedia.Internals.VLEFluidConfigurations.FullyMixtureCompatible.VLEFluidFunctions.liquidDensity_phxi(medium, fluidPortIn.p, inStream(fluidPortIn.h_outflow), inStream(fluidPortIn.xi_outflow)) | |
| SI.HeatFlowRate | Q_consumer_is | fluidPortIn.m_flow*inStream(fluidPortIn.h_outflow) + fluidPortOut.m_flow*fluidPortOut.h_outflow | |
| Modelica.Blocks.Nonlinear.Limiter | m_flow_lim_set | ||
| Modelica.Blocks.Continuous.FirstOrder | m_flow |