modelIndirect_HEX_const_dT_L1
Constant dT Heat Exchanger Model
Extends from TransiEnt.Producer.Heat.Base.PartialHEX.
Information
1. Purpose of model
Simple heat exchanger model specifically modeled to be used in district heating networks.
2. Level of detail, physical effects considered, and physical insight
(no remarks)
3. Limits of validity
(no remarks)
4. Interfaces
(no remarks)
5. Nomenclature
(no remarks)
6. Governing Equations
Calculates the necessary mass flow for a constant dT between supply and return:
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 | 90 + 273.15 | Temperature at start of simulation |
| Real | dT_set | simCenter.dT | Setpoint temperature difference between supply and return pipe |
| SI.MassFlowRate | m_flow_min | 0.01 | Minimum mass flow rate to counteract possible zero massflow sitations |
| SI.SpecificHeatCapacityAtConstantPressure | cp | TIL.specificIsobaricHeatCapacity_pTxi(simCenter.fluid1, simCenter.p_nom[2], T_start, {1, 0, 0}) |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealInput | Q_demand | ||
| Modelica.Blocks.Interfaces.RealOutput | T_out_calc | ||
| Modelica.Blocks.Interfaces.RealOutput | m_flow | ||
| Modelica.Blocks.Interfaces.RealInput | T_in |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.SimCenter | simCenter | ||
| SI.HeatFlowRate | Q_withdrawal | Heat taken out of the district heating | |
| SI.Temperature | T_out | Outlet temperature of the ideal HEX |