modelSubstation_indirect_noStorage_L1
Information
1. Purpose of model
District heating Substation model without a storage based on mass flow calculation for constant dT.
2. Level of detail, physical effects considered, and physical insight
Ideal temperature difference assumed.
3. Limits of validity
(no remarks)
4. Interfaces
inlet: a fluid port for the inflowing heat transfer medium
outlet: a fluid port for the outflowing heat transfer medium
real input: heating demand of the consumer
real input: hot water demand of the consumer
5. Nomenclature
(no remarks)
6. Governing Equations
Based upon the calculation of necessary mass flow for a given temperature difference at heat demand and the Richmann's Rule of mixture.
7. Remarks for Usage
Due to the simple nature of the model, it is important to have a realistic supply temperature to avoid the return temperature to fall below possible values.
8. Validation
(no remarks)
9. References
(no remarks)
10. Version History
Model created by Philipp Huismann (huismann@gwi-essen.de), Oct 2018
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Temperature | T_start | simCenter.T_supply | Temperature at start of the simulation |
| SI.MassFlowRate | m_flow_min | simCenter.m_flow_min | Minimum mass flow rate to counteract possible zero massflow sitations, equals a simplified bypass |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.Basics.Interfaces.Thermal.FluidPortOut | waterPortOut | ||
| TransiEnt.Basics.Interfaces.Thermal.FluidPortIn | waterPortIn | ||
| Modelica.Blocks.Interfaces.RealInput | Q_demand_RH | ||
| Modelica.Blocks.Interfaces.RealInput | Q_demand_DHW |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.SimCenter | simCenter | ||
| TransiEnt.ModelStatistics | modelStatistics | ||
| SI.Temperature | T_mix | Mixing temperature from room and domestic hot water | |
| room_heating_hex_model | room_heating_hex | ||
| dhw_heating_hex_model | domestic_hot_water_hex | ||
| Modelica.Blocks.Math.Gain | signChanger_2 | ||
| ClaRa.Components.Sensors.SensorVLE_L1_T | T_in_sub | ||
| Modelica.Blocks.Math.Add | add_supply | ||
| Modelica.Blocks.Math.Add | add_return | ||
| ClaRa.Components.BoundaryConditions.BoundaryVLE_Txim_flow | m_flow_in | ||
| ClaRa.Components.BoundaryConditions.BoundaryVLE_Txim_flow | m_flow_out | ||
| Modelica.Blocks.Math.Gain | signChanger_1 | ||
| ClaRa.Components.Sensors.SensorVLE_L1_T | T_out_sub |
Contents
| Name | Description |
|---|---|
 room_heating_hex_model | |
| dhw_heating_hex_model |