modelDynamicPipe
Extends from AixLib.Obsolete.BaseClasses.ObsoleteModel.
Information
Overview
This model is based on pipeBase. The pipes parameter can be chosen from DataBase or entered manually . This model takes into account the heat loss due to convection and / or radiation and insulation can also be chosen.
Concept
The fluid inside the pipe is represented by the model HeatCapacitor. Two cilindrical layers with heat conduction and heat storage where added for the pipe wall and pipe insulation each.
The model directly calculates radiation and convection instead of modeling these phenomena outside the pipe, an ambient temperature can be prescribed at the heat-port and the star of the pipe and the loss to ambient will be calculated within the pipe model. The purpose is to clean up bigger models and to simplify modeling systems with pipes outside building-walls.
Please note that it's not possible to consider radiation without considering convection.
Also, be careful when using neither isolation nor convection, as this will result in ideal heat transfer to the outside of the pipe and so to a significant heat loss. Might be useful if used for example for CCA (concrete core activation).
Example Results
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | selectable | true | Pipe record |
| FastHVAC.Media.BaseClasses.MediumSimple | medium | FastHVAC.Media.WaterSimple() | Mediums charastics (heat capacity, density, thermal conductivity) |
| Modelica.Units.SI.Temperature | T_0 | Modelica.Units.Conversions.from_degC(20) | Initial temperature of fluid |
| Integer | nNodes | 3 | Number of discrete flow volumes |
| AixLib.DataBase.Pipes.PipeBaseDataDefinition | parameterPipe | AixLib.DataBase.Pipes.Copper.Copper_6x1() | Type of pipe |
| Boolean | withInsulation | true | Option to add insulation of the pipe |
| AixLib.DataBase.Pipes.InsulationBaseDataDefinition | parameterIso | AixLib.DataBase.Pipes.Insulation.Iso100pc() | Type of Insulation |
| Boolean | withConvection | false | = true to internally simulate heat loss to ambient by convection |
| Boolean | withRadiation | false | = true to internally simulate heat loss to ambient by radiation (only works with convection = true) |
| Boolean | withRadiationParam | if not withConvection then false else withRadiation | = true to internally simulate heat loss to ambient by radiation (only works with convection = true) |
| Modelica.Units.SI.CoefficientOfHeatTransfer | hConOut | 8 | Heat transfer coefficient to ambient |
| Modelica.Units.SI.Emissivity | eps | 0.8 | Emissivity |
| Boolean | calcHCon | true | Use calculated value for inside heat transfer coefficient |
| Modelica.Units.SI.CoefficientOfHeatTransfer | hConIn_const | 30 | Fix value for heat transfer coeffiecient inside pipe |
| Geometry | |||
| Integer | nParallel | 1 | Number of identical parallel pipes |
| Modelica.Units.SI.Length | length | 1 | Length of pipe |
| Modelica.Units.SI.Diameter | diameter | 0.01 | Inner diameter of pipe (if selectable=false) |
| Modelica.Units.SI.Thickness | s_pipeWall | 0.001 | Thickness of pipe wall (if selectable=false) |
| Pipe material | |||
| Modelica.Units.SI.Density | rho_pipeWall | 8900 | Density of pipe material (if selectable=false) |
| Modelica.Units.SI.SpecificHeatCapacity | c_pipeWall | 390 | Heat capacity of pipe material (if selectable=false) |
| Modelica.Units.SI.ThermalConductivity | lambda_pipeWall | 393 | Thermal Conductivity of pipe material (if selectable=false) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| AixLib.Utilities.HeatTransfer.CylindricHeatTransfer | pipeWall | ||
| AixLib.Utilities.HeatTransfer.CylindricHeatTransfer | insulation | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort_outside | ||
| FastHVAC.Interfaces.EnthalpyPort_a | enthalpyPort_a1 | ||
| FastHVAC.Interfaces.EnthalpyPort_b | enthalpyPort_b1 | ||
| AixLib.Utilities.Interfaces.RadPort | star | ||
| AixLib.Utilities.HeatTransfer.HeatConv | heatConv | Convection from pipe wall | |
| AixLib.Utilities.HeatTransfer.HeatToRad | twoStar_RadEx | ||
| FastHVAC.Components.Pipes.BaseClasses.PipeBase | pipeBase |
Revisions
-
November 17, 2017 David Jansen:
Reduced pipe models to two versions and moved to development -
December 20, 2016 Tobias Blacha:
Moved into AixLib -
January 27, 2015 by Konstantin Finkbeiner:
Addapted to FastHVAC -
November 26, 2014 by Roozbeh Sangi:
Updated connectors to EBC Library 2.2, Updated documentation, Added example -
May 19, 2014 by Roozbeh Sangi:
Added to the HVAC library -
November 13, 2013 by Ole Odendahl:
Formatted documentation appropriately -
August 9, 2011 by Ana Constantin:
Introduced the possibility of neglecting the insulation wall -
April 11, 2011 by Ana Constantin:
Implemented