modelMonoLayerDynamic
Dynamic layer for uniform solid.
Information
For the purpose of dynamic building simulation, the partial differential equation of the continuous time and space model of heat transport through a solid is most often simplified into ordinary differential equations with a finite number of parameters representing only one-dimensional heat transport through a construction layer. Within this context, the wall is modelled with lumped elements, i.e. a model where temperatures and heat fluxes are determined from a system composed of a sequence of discrete resistances Rn+1 and capacitances Cn. The number of capacitive elements n used in modelling the transient thermal response of the wall denotes the order of the lumped capacitance model.
Cc · dTc / dt = Σi=1n Q̇res,i + Q̇source
where
- Tc is the temperature of the lumped capacity,
- Q̇res is the heat flux through the lumped resistance,
- Rres is the total thermal resistance of the lumped resistance,
- Q̇source are internal thermal sources that represent the added energy to the lumped capacity, and
- Cc is the thermal capacity of the lumped capacity, equal to (ρ · cp · dc · A), where
- ρ denotes the density,
- cp is the specific heat capacity of the material,
- dc is the equivalent thickness of the lumped capacity, and
- A is the surface area of the wall.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Area | A | Layer area | |
| IDEAS.Buildings.Data.Interfaces.Material | mat | Layer material | |
| Modelica.Units.SI.Temperature | T_start | 293.15 | Start temperature for each of the states |
| Integer | nStaMin | 2 | Minimum number of states |
| Boolean | present | mat.d > Modelica.Constants.small | |
| Integer | nSta | max(nStaMin, mat.nSta) | Number of states |
| Real | R | mat.R | Total specific thermal resistance |
| Modelica.Units.SI.HeatCapacity | Ctot | A*mat.rho*mat.c*mat.d | Total heat capacity |
| Boolean | addRes_b | false | Set to true to add a resistor at port b. |
| Dynamics › Equations | |||
| Modelica.Fluid.Types.Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamics.FixedInitial | Static (steady state) or transient (dynamic) thermal conduction model |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealOutput | E | sum(T.*C) | |
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | port_a | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_b | port_b |
Revisions
-
June 17, 2025, by Lucas Verleyen:
Replaced images with inline equations. See #1440. -
January 25, 2019, by Filip Jorissen:
Revised initial equation implementation. See issue #971. -
January 25, 2018, by Filip Jorissen:
PropagatedT_startin the declaration ofT. See issue #692. -
December 8, 2016, by Filip Jorissen and Damien Picard:
Revised implementation of placeCapacityAtSurf_b, which has been renamed to addRes_b. This is for solving problems when linearising a model. See issue 591. -
February 10, 2016, by Filip Jorissen and Damien Picard:
Revised implementation.