modelConnectionCondensatePipe
Extends from Buildings.DHC.Networks.BaseClasses.PartialConnection2Pipe2Medium (Partial model for connecting an agent to a two-pipe distribution network with two medium declarations).
Information
This network connection model contains one pipe declaration for the condensate pipe, featuring a fixed hydraulic resistance. This model is intended for steam heating systems that utilize a split-medium approach with two separate medium declarations between liquid and vapor states.
In this model, it is assumed that there are no mass losses in the network connection. Further, heat transfer with the external environment and transport delays are also not included.
References
Kathryn Hinkelman, Saranya Anbarasu, Michael Wetter, Antoine Gautier, Wangda Zuo. 2022. “A Fast and Accurate Modeling Approach for Water and Steam Thermodynamics with Practical Applications in District Heating System Simulation,” Energy, 254(A), pp. 124227. 10.1016/j.energy.2022.124227
Kathryn Hinkelman, Saranya Anbarasu, Michael Wetter, Antoine Gautier, Baptiste Ravache, Wangda Zuo 2022. “Towards Open-Source Modelica Models For Steam-Based District Heating Systems.” Proc. of the 1st International Workshop On Open Source Modelling And Simulation Of Energy Systems (OSMSES 2022), Aachen, German, April 4-5, 2022. 10.1109/OSMSES54027.2022.9769121
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | n | 2 | Flow exponent, n=1 for laminar, n=2 for turbulent |
| General › Nominal condition | |||
| Modelica.Units.SI.MassFlowRate | mDis_flow_nominal (from PartialConnection2Pipe2Medium) | Nominal mass flow rate in the distribution line | |
| Modelica.Units.SI.MassFlowRate | mCon_flow_nominal (from PartialConnection2Pipe2Medium) | Nominal mass flow rate in the connection line | |
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialConnection2Pipe2Medium) | false | = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
| Dynamics › Equations | |||
| Modelica.Fluid.Types.Dynamics | energyDynamics (from PartialConnection2Pipe2Medium) | Modelica.Fluid.Types.Dynamics.FixedInitial | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics › Nominal condition | |||
| Modelica.Units.SI.Time | tau (from PartialConnection2Pipe2Medium) | 10 | Time constant at nominal flow for dynamic energy and momentum balance |
| Nominal condition | |||
| Modelica.Units.SI.PressureDifference | dp_nominal | Pressure drop at nominal mass flow rate | |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | port_aDisSup (from PartialConnection2Pipe2Medium) | Distribution supply inlet port | |
| Modelica.Fluid.Interfaces.FluidPort_b | port_bDisSup (from PartialConnection2Pipe2Medium) | Distribution supply outlet port | |
| Modelica.Fluid.Interfaces.FluidPort_a | port_aDisRet (from PartialConnection2Pipe2Medium) | Distribution return inlet port | |
| Modelica.Fluid.Interfaces.FluidPort_b | port_bDisRet (from PartialConnection2Pipe2Medium) | Distribution return outlet port | |
| Modelica.Fluid.Interfaces.FluidPort_b | port_bCon (from PartialConnection2Pipe2Medium) | Connection supply port | |
| Modelica.Fluid.Interfaces.FluidPort_a | port_aCon (from PartialConnection2Pipe2Medium) | Connection return port |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Model_pipDisSup | pipDisSup (from PartialConnection2Pipe2Medium) | Distribution supply pipe | |
| Model_pipDisRet | pipDisRet (from PartialConnection2Pipe2Medium) | Distribution return pipe | |
| Buildings.Fluid.FixedResistances.Junction | junConSup (from PartialConnection2Pipe2Medium) | Junction with connection supply | |
| Buildings.Fluid.FixedResistances.Junction | junConRet (from PartialConnection2Pipe2Medium) | Junction with connection return | |
| Buildings.Fluid.FixedResistances.PressureDrop | pipConRet | Connection return pipe |
Revisions
-
June 17, 2026, by Michael Wetter:
Updated implementation to allow a flow coefficientnthat is different from2. This allows use of the model for not fully turbulent flow.
This is for Buildings, #4620. -
September 15, 2023, by Kathryn Hinkelman:
Updated publication references. -
March 2, 2022, by Kathryn Hinkelman:
First implementation.