modelIndirect_HEX_const_T_out_L1
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 such that the return temperature doesn't fall below possible values.
8. Validation
(no remarks)
9. References
(no remarks)
10. Version History
Model created by Philipp Huismann (huismann@gwi-essen.de) on 10.10.2018
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Temperature | T_start | 90 + 273.15 | Temperature at start of simulation |
| SI.HeatFlowRate | Q_max | 90*1000 | Maximum Heat Supply |
| SI.MassFlowRate | m_flow_max | Q_max/(cp*(simCenter.T_supply - simCenter.T_return)) | Minimum mass flow rate |
| SI.MassFlowRate | m_flow_min | simCenter.m_flow_min | Minimum mass flow rate |
| SI.SpecificHeatCapacityAtConstantPressure | cp | TIL.specificIsobaricHeatCapacity_pTxi(simCenter.fluid1, simCenter.p_nom[2], T_start, {1, 0, 0}) | |
| SI.Temperature | T_out_const | simCenter.T_return | Desired constant outlet temperature |
| SI.Efficiency | overflow_rate | 1 | Used to introduce inefficiencies in heat transfer by scaling the calculated mass flow |
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.MassFlowRate | m_flow_calc | ||
| Modelica.Blocks.Sources.RealExpression | realExpression | ||
| Modelica.Blocks.Continuous.FirstOrder | T_in_delayed | ||
| Modelica.Blocks.Math.Gain | usedT |